Building Capacity

Green Gut Rehab Serves as Building Science Laboratory for Guild’s 2011 Green Home Tour: Interview with Colleen Groll, CSBA, LEED AP Homes, Energy Star Verifier and Performance Tester

Colleen Groll, Residential Services Manager and Senior Project Associate at O’Brien & Company, is in the process of finishing up a gut rehab in attempt to convert a leaky 1918 “fixer” into an energy-efficient, comfortable, and healthy home with optimized functionality.

Editor: What were you hoping to accomplish with your remodel? Colleen: Generally I was hoping to modernize an architecturally traditional shell, so it feels and functions more like 2011. My sustainable building goals were mainly around energy efficiency and indoor air quality. I was hoping to achieve LEED for Homes Platinum, but now I’ll be happy with Gold.

So you’ve had to rethink your LEED goals? Yes. We had major challenges working with existing 2x4 construction, lots of structural issues we had to address. Gut rehabs tend to expand exponentially as you open up the walls, and I ran up against the limits of my budget trying to get the home structurally sound and ready for earthquakes. We basically had to rebuild the house.

LEED Gold is pretty good, though! What have you been able to do to earn your spot in the Guild’s Green Tour? Green building features are incorporated throughout, including: double 2x4 walls for super insulation; high performance “heat mirror” windows; diligent air sealing; high-efficiency boiler for domestic hot water and radiant heating; heat recovery ventilation; water-efficient low flow fixtures; metal roof for future rainwater collection; and numerous salvaged materials such as flooring, cabinetry, doors.

We’re also offering a Building Science Laboratory to those touring the house. O’Brien & Company will have a team of Green Raters and Green Building Consultants on hand as we perform a Blower Door Test on the house four times each day (check the website for the schedule). We’ll also have an InfraRed (IR) camera on hand to demonstrate various diagnostic tools and techniques. We’ll be sealing up the last leaky areas during the tour. The ultimate question everyone asks is how much the project cost you.

Care to share? Sure, I’ve spent $167 a square foot.

 

What practical tips would you offer to someone trying the same thing, or others wanting to help others try the same thing?

• Do lots of up front research on green strategies to see what fits your situation.
• Have a great contractor with green building experience if possible, or at least one that is enthusiastic about the process.
• Plan on working hard on air sealing, the unsung hero of energy efficiency. I call it: spray, caulk, foam, then pray and repeat.
• Be prepared to recalibrate your goals. In a gut rehab, a lot of your budget may have to go, like mine did, on things like getting your shear walls, foundations, and house to foundation connections up to snuff.
• Prioritize. You can’t have it all. I wanted a functional, modern building that was energy efficient, healthy, and comfortable. Aesthetics are very important to me, but the green/energy efficiency goals came first.

Colleen’s project is one of 27 featured on the 2011 Northwest EcoBuilding Guild Tour this April 16th and 17th, and one of two associated with O’Brien & Company. The second is Bastyr University Housing, a LEED Gold project featured earlier this year in the Building Capacity Blog. For more info on how to build or remodel a home in the Cascadia region (southern British Columbia to Northern California) check out The Northwest Green Home Primer , which will be available for sale to visitors at Colleen’s project and at A Mighty House, another home on the tour.

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Tips for Optimizing Forced-Air Heating and Cooling Systems Part 1
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How do you optimize a forced-air system to maintain a green home? Alistair Jackson, LEED AP for Homes Rater Responds: Part 4: MECHANICAL VENTILATION

If not installed or maintained properly, forced-air heating and cooling systems can perform poorly, creating air quality problems and unnecessary expense. To optimize a forced-air system, you need to design or refine it to prevent leaks and pressure imbalances, protect it properly during construction (or make sure the ductwork is clean and sound), and use the right filter.

The performance spec of the heat (or cooling) source is also important, but it is critical to address the distribution system first before investing in better furnace and air handler performance. This article is the FINAL of four focused on optimizing forced-air systems on the topics of Distribution, Filtration, Heat Source (and Controls), and Ventilation.

Whether in a new house or an existing home, mechanical ventilation is an important component of indoor comfort and building durability. Here in Washington, codes have required it for several years, but that doesn’t necessarily mean the ventilation system in a home is effective.

This is another system that is worth having tested by a qualified contractor to see if it is over- or under-performing. A system that is under-performing (provides less airflow than recommended) may not provide adequate fresh air or remove enough moisture from the home. A system that is over-performing (providing too much airflow) will increase energy consumption, as heating system has to heat or cool the additional volume of  air.

The ventilation performance requirements of the IRC 2009 (and the current Washington Residential Code) are consistent with ASHRAE 62.2-2007, a recognized national reference standard, and a great performance benchmark even for a project that isn’t covered by the code. The intent of this standard is to ensure adequate air changes in the home, based on size and occupancy load. It requires mechanical ventilation with dedicated outside air inlets in new construction to increase the likelihood of effective ventilation.

For existing homes, it should be noted that mechanical ventilation becomes increasingly important as the building envelope becomes more air-tight. If a blower door test gives a result of ≥7 ACH@50, the focus should be on reducing envelope leakage rather than adding mechanical ventilation. This test result is roughly equivalent to 0.35 nACH or about one air change every three hours. With this much leakage in the envelope, the house will experience more than enough ventilation through the natural convection caused by “stack effect” as well as those induced by the influence of wind on the structure. But if your envelope weatherization efforts have brought envelope leakage substantially below this level, adding effective mechanical ventilation is a top priority.

Let’s assume we’re talking about a project that has successfully upgraded the building envelope to something less than 4 ACH50. A common practice in forced air homes is to integrate a mechanical ventilation system into the forced air system; a logical approach since you already have a system of ducts to deliver air to all the living spaces. This is called a “Central Fan Integrated System (CFIS)” – Imagine that. It is a straightforward solution that can be properly implemented for around $500 as long as your distribution ductwork is clean and sound and there’s easy access for a duct run from your air handler to an exterior wall, away from other exhaust outlets.

In its simplest form, this approach consists of a duct into the return side of the air handler, drawing fresh air into the system whenever the air handler fan runs. The problem with this approach is that the ventilation rate is totally dependent on how much the air handler runs. So on the coldest days (or the warmest days in a cooling-dominated climate) you get the greatest ventilation. On these days, the outside air also needs more conditioning to meet the indoor set-point temperature – so that means more heating (or cooling) energy; a recipe for higher energy bills.

                                      

This can be mitigated by adding a “fan cycler” – a control box connected to a mechanical damper in the fresh air duct. See the mechanics of an AprilAire fan cycler  in the photo at left. The fan cycler opens and closes the fresh air duct and monitors how much time the fan runs with the duct open. On cold days, it will close the fresh air duct once the ventilation air volume for a given period has been reached. On mild days, when heat (or cooling) demand is low, it will also switch on the air handler fan to circulate fresh air to meet the ventilation requirement. The disadvantage of this action is that it uses the large air handler fan (and associated electrical consumption) to circulate a relatively small amount of fresh air. If your air handler includes an efficient, variable speed fan this impact is significantly reduced. Aircycler provides an interactive  schematic showing the airflow.

 

Another approach that reduces fan energy is to tie the Fan Cycler to one or more exhaust fans and use these fans to pull outside air through the ducts when the air handler is not running. Energy Star labeled fans from Panasonic and others use a fraction of the energy of a typical air handler fan. I’m not personally convinced this solution provides good outside air distribution but it may be worth further exploration.

Energy (or heat) recovery, where energy from the stale exhaust air is used to pre-condition the incoming fresh air, can also be integrated into this approach. Typically, the air handler fan of an HRV or ERV is not large enough to effectively circulate fresh air through the large, forced air duct system, resulting in inadequate distribution and mixing of outside air. It is better to integrate the ERV/HRV with a fan cycler and use the furnace air handler fan, (Venmar AVS used to sell a passive  HRV unit called the Enerflo, that offered all this in one convenient unit, but I’m not sure this product is still available – comment if you know differently!).

You can also install small diameter, dedicated ductwork for the ventilation air distribution. Either approach will involve increased installation cost and control complexity (see the photo). In simple payback terms, this probably only makes sense in very cold or hot climates.

 

IMPORTANT NOTE: Any CFIS system requires proper commissioning by a qualified technician to ensure it is performing properly and delivering the required rate of ventilation in a range of conditions. Your HVAC contractor may be able to provide this service, or you may choose to use an independent contractor such as those listed with Home Performance Washington, RESNET, Building Performance Institute (BPI), National Comfort Institute Certified Contractors. 

Alistair Jackson, LEED AP, CSBA is Principal in Charge of O’Brien & Company’s Residential Technical Services, and is a LEED for Homes, Energy Star and Built Green Verifier, LEED for Homes Faculty and ARCSA certified Rainwater Harvesting designer. Alistair is a frequent contributor to the Building Capacity Blog and was also a major contributor to the Northwest Green Home Primer.

Did you enjoy this article?  You might also like these Building Capacity Blog articles:
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 1
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 2
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 3
Interview with LINC’s Maria Elena Marquez-Brookes
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How do you optimize a forced-air system to maintain a green home? Alistair Jackson, LEED AP for Homes Rater Responds: Part 3: HEAT SOURCE & CONTROLS

If not installed or maintained properly, forced-air heating and cooling systems can perform poorly, creating air quality problems and unnecessary expense. To optimize a forced-air system, you need to design or refine it to prevent leaks and pressure imbalances, protect it properly during construction (or make sure the ductwork is clean and sound), and use the right filter.

The performance spec of the heat (or cooling) source is also important, but it is critical to address the distribution system first before investing in better furnace and air handler performance. This article is the THIRD of four focused on optimizing forced-air systems on the topics of Distribution, Filtration, Heat Source (and Controls), and Ventilation.

The most effective upgrades to the heat source in a forced air system are typically: 1) Improve the thermal envelope of the home; and 2) Seal and insulate the ductwork. Once those things are done, investments in improving the furnace or heat pump are likely to be returned to the homeowner rather than being lost. If you’ve dealt with those, then consider the following.

CONTROLS

The simplest way to improve performance of an existing system is to add a programmable thermostat, if it doesn’t already have one. EPA claims you can reduce energy consumption by 5% to 15% with a properly programmed thermostat. But there’s the rub. Just installing it doesn’t help; it has to be properly programmed. Make sure it’s set up and the homeowner knows how to use and reprogram it. Heat pumps need a heat pump thermostat. In cold climates, many say it doesn’t pay to set back the night time temperature with a heat pump system, because the system will switch to electric strip heat during the early morning warm up cycle. However, the better heat pump thermostats include algorithms in their programming to lock out or minimize the use of strip heat at such times, which can significantly reduce overall energy consumption.

Zoning can be an energy-saving upgrade. This can be achieved in a forced air system by including motorized dampers to control air flow to each zone, controlled by multiple thermostats connected to a system controller that operates the heat source and air-handler. Once again, it is important to have a reasonably air-tight, thermally efficient building envelope before you think about this upgrade, or it may lead to unanticipated comfort and control issues. Zoning can be difficult to retrofit depending on the duct design and accessibility. Since turning off a zone reduces the effective size of the system it can result in too much back pressure which may damage the air handler. For this reason, zoned systems generally use oversized ductwork, though there are other ways to address this.

HEAT SOURCES

What if it is in the budget to think about upgrading the heat source? I’m only going to address a few big picture issues here, since this is a huge topic with a lot of great resources available on the web and elsewhere.

First - Make sure the person who designs the HVAC system does a proper room-by-room load calculation, using a reputable tool (ask for ACCA Manual J or equivalent) the actual design specs for the home (floor, wall and ceiling insulation values, glazing area and u-factors, envelope infiltration rates). This way, the heat source will be properly sized for the house and sufficient heat will be delivered to each room. If the loads are significantly different from the original system design, the ductwork may also be oversized and may require some redesign, too.

Second – If you have the option, locate the heat source and all the distribution ductwork inside the conditioned space, eliminating almost all the heat loss to the outside. This can be challenging in smaller homes or retrofit situations, but it can be done. If you are retaining the existing ductwork, this likely means relocating the thermal and pressure envelope to enclose the mechanical space and should only be done if you are using a closed combustion appliance.

Third - Consider a multi-stage heat source (gas furnace or high-efficiency electric heat pump). Since a heating system is designed to provide enough heat to keep the home comfortable on the coldest day of the year, it spends most of the heating season running at less than full capacity, which is generally less efficient. In a combustion system (furnace), this means the burner/gas valve has more than one heating level, so it can modulate how much gas is burned according to the amount of heat that is needed. A dual stage furnace might have a peak capacity of 60 kBTUh and a first-stage capacity of 30kBTUh. In a house with a peak heating load (the heat required to keep the inside of the house comfortable on the theoretical coldest day of the year) of 24 kBTUh (not uncommon for a typical, quality-built 3- or 4 bedroom house), such a furnace might NEVER use the full 60 kBTUh capacity.

In a heat-pump system, performance depends on the outdoor compressor unit’s ability to extract heat from the outside air – the colder the outside air, the harder it is to get heat from it. So on the cold days when more heat is needed inside, there is less heat available outside. In older heat pump systems, this situation triggers the “Emergency Heat” source, electric resistance heat strips in the heat exchanger. This is expensive and inefficient. There are a few cold climate forced air heat pumps that use multiple, staged compressors to address this. They seem to perform well but availability and technical support is currently limited and these systems do need specialist attention. To address this, some HVAC installers recommend hybrid systems with a heat pump AND a combustion furnace – the furnace replaces the electric emergency heat with a more efficient gas combustion supply. This is more efficient, but it adds a lot of cost and equipment up front.

The latest in heat pump technology features multi-stage or variable speed compressors. With this technology, heat pumps can deliver satisfactory heating performance even at outdoor temperatures well below freezing. The heat-extracting capacity of the outdoor units is matched to the outdoor temperature and the need for heat indoors, so that the system runs at its most efficient whatever the conditions. 

While this technology is commonly available in Ductless Mini-split heat pumps, which are a great solution for smaller homes with small heating and cooling loads (typically less than 1-ton per unit), it is not available in ducted forced air systems – at least not yet. In a smaller home with a thermally efficient envelope, however, abandoning the forced air system altogether and installing one or two ductless mini-split heat pumps may yield great, energy efficient and comfortable results. But that’s for another column.(Just to whet your appetite, we understand that several mini-split heat pumps, most notably the Fujitsu Halcyon system pictured in the photo, perform quite well in our Northwest climate).  We are waiting with baited breath to get the results from a two-winter study of heat pump technology being conducted by the Northwest Energy Efficiency Alliance.  For a great overview of heat pumps, check out Green Building Advisor.

Fourth – Use a variable speed fan. The air handler – the fan that moves air around the building – provides another opportunity to improve performance. Most air handler fans are single-speed units – they blow at the same speed whenever they are switched on, using the same amount of electricity. Variable speed fans (which typically use Variable Frequency Drives or VFDs, or Electrically Commutated Motors or ECMs) are an optional upgrade, often standard in higher-efficiency furnace packages. When a house is at a steady temperature, it takes relatively little heated air to keep it comfortable. A variable speed fan will run at a much lower speed in these conditions – reducing energy consumption and noise. (See my fourth and last installment of this series on Ventilation, next week).

FUEL TYPE

Climate – In moderate heating climates, where it rarely stays much below freezing, and in cooling dominated climates, electric air-to-air heat pumps are a good choice. In cold climates, a combustion-based heat source is generally preferred - natural gas if it is available, propane or fuel oil if it is not. But be aware that oil and propane prices fluctuate significantly with supply and demand, sometimes making them more expensive than electricity in the heating season. If gas is not available, and the budget allows, it might be worth considering a ground-source heat pump. Very high efficiencies are achievable but unless you are dealing with large heating and/or cooling loads, the simple payback on such a system will be very long. Other benefits, such as quietness and reduced carbon footprint may be important to the homeowner (see fuel source).

Fuel Source - If your homeowner is concerned about carbon emissions and your electricity comes from gas, oil or coal, an electric-based heating system is probably not the greenest choice. Because of distribution inefficiencies in the electricity grid, you get less than half the energy value of the source fuel delivered to your house as electricity. Better to burn that fuel in a high efficiency appliance in the house and get 90%+ of the fuel value. A heat pump is much more efficient than electric resistance heating, but only the most efficient air-to-air heat pumps for forced air systems offer enough efficiency to offset the grid energy losses (look for HSPF of 9.5 and above, or a COP of 2.5 or better). In the Pacific Northwest, we are less carbon-dependent because of the large portion of hydroelectric power in our grid energy. Also, in the area west of the Cascades and Coast Ranges, we have mild climates, making heat pumps a great choice. In all cases, if you choose an electric system, consider a green power purchase to effectively neutralize those carbon emissions

Alistair Jackson, LEED AP, CSBA is Principal in Charge of O’Brien & Company’s Residential Technical Services, and is a LEED for Homes Rater, LEED for Homes Faculty, Energy Star Verifier and Performance Tester, ARSCA Accredited Professional, and Built Green Verifier. He is a regular contributor to the Building Capacity Blog, and was a major contributor to the Northwest Green Home Primer on the subject of home operating systems and the energy picture. He is a regular

Did you enjoy this article?  You might also like these Building Capacity Blog articles:
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 1
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 2
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 4
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How do you optimize a forced-air system to maintain a green home? Alistair Jackson, LEED AP for Homes Responds: Part 2: FILTRATION

If not installed or maintained properly, forced-air heating and cooling systems can perform poorly, creating air quality problems and unnecessary expense. To optimize a forced-air system, you need to design or refine it to prevent leaks and pressure imbalances, protect it properly during construction (or make sure the ductwork is clean and sound), and use the right filter.

The performance spec of the heat (or cooling) source is also important, but it is critical to address the distribution system first before investing in better furnace and air handler performance. This article is the SECOND of four focused on optimizing forced-air systems on the topics of Distribution, Filtration, Heat Source, and Ventilation.

Some are inclined to believe that forced air systems are more of a cause of air quality problems than a solution. However, one of the advantages they offer is the ability to continuously filter the re-circulating indoor air as well as the outside ventilation air (in a central fan integrated system). While filtration shouldn’t replace efforts to reduce source contaminants, this can be a real bonus to homeowners who have pets (including small children :), live in areas with a lot of particulates in the outside air or have a need for highly-filtered indoor air.

Filters in forced air systems are generally (and preferably) located in the return trunk immediately upstream of the air handler, though sometimes they are located at central return grilles. An important consideration here is accessibility – filters must be cleaned or changed according to manufacturers’ instructions to maintain performance and minimize wear and tear on the equipment. So they should be easily accessible to the homeowner and the access door should be air-sealed in such a way that it will reseal easily and effectively, even after it’s been opened multiple times.

If the air handler is in a garage or mechanical closet, that’s probably a good place for the filter, but if it is in an attic, crawl space or other location that’s hard to reach installing high-efficiency 1-inch filters at the central return grilles might increase the likelihood they’ll get changed regularly. Clogged filters will reduce the air flow through the system, affecting comfort and energy efficiency and potentially increasing wear and tear on the system.

Use the highest efficiency filter appropriate for the system, preferably a filter with a MERV rating of 10 or higher. MERV, or Minimum Efficiency Reporting Value, is a simplified expression of the effectiveness of a filter at removing particles of different sizes from the air stream flowing through it. What you need to know is that MERV is a scale from 1 to 16, that 10 and above are considered to be high-efficiency, and that the non-woven, fiberglass filter that was supplied with your furnace (and may still be in there . . .) probably wouldn’t even get a MERV of 1! (Such filters are installed to protect the air handler from large dirty objects, not your respiratory system from small ones.) If you want more details on what MERV is really all about, visit the National Air Filtration Association website.

If you are upgrading the filter in an existing system, bear in mind that for a given surface area of filter, the higher the MERV rating, the greater the pressure drop across it. One inch filters above MERV 11 may cause sufficient pressure drop to significantly affect the performance of an existing system. If you are upgrading the air handler, the fan/blower spec can be altered to accommodate this, but if you’re adding more efficient filtration to an existing air handler it may be worth increasing the surface area of the filter. This typically means switching to a thicker, pleated filter (perhaps 3” or 4”) which may create an installation challenge in the existing sheet metal. However, if the upgrade also includes full duct sealing and insulation, the reduced losses in the system may offset the reduced flow from a moderate improvement in filter performance. Measuring the pressure drop across the filter and in various parts of the system will provide useful data to support good design decisions. Add a manometer (such as the JMW digital manometer pictured above,  and the know-how to use it to your toolbox, or find an HVAC balancing contractor or home energy specialist to assist you.

Make sure the homeowner understands the maintenance requirements of medium- or high-efficiency filters, the benefit of fulfilling those requirements, and the downside of not doing so. The photo to the left shows two filters, one new and one with just a few months of wear that is quite clogged.

Filters with the lowest first cost, such as one-inch (1”) pleated media, require regular replacement (four times per year), amounting to considerable cost over time. Four-inch pleated media filters are now commonly available. Though they cost more individually, they generally require less frequent replacement (so have a lower lifecycle cost) and cause less pressure drop than a 1” filter of similar cross-sectional area. For systems in big homes that move large volumes of air, high efficiency bag-type filters (some of which are washable) may be a worthwhile consideration.

Although electrostatic air filters enjoy a PR buzz, green designers generally don’t recommend them. To maintain their performance, they should be cleaned as often as once or twice per month, and most homeowners are not willing to keep that schedule up. When they’re dirty, their filtration performance drops dramatically, and they may generate and introduce ozone—a significant respiratory irritant—into indoor air stream.

Next week we’ll be looking at heat sources in a little more detail.

Diagnostic HVAC Resources: To find a qualified Home Performance Testing contractor, check out websites for Building Performance Institute (BPI) or RESNET. If you are located in Washington see Home Performance Washington or Northwest Energy Star. To locate a Balancing Contractor, see National Comfort Institute Certified Contractors.

Alistair Jackson, LEED AP, CSBA is Principal in Charge of O’Brien & Company’s Residential Technical Services, and is a LEED for Homes Rater, LEED for Homes Faculty, Energy Star Verifier and Performance Tester, ARSCA Accredited Professional, and Built Green Verifier. Alistair was also a major contributor to the Northwest Green Home Primer where much of the information for this article originally appeared. It has been expanded upon for this publication.

Did you enjoy this article? You might also like these Building Capacity Blog articles:
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 1
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 3
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 4
Mechanical Systems and Fuel Choices for the Warming World
Cracking the Energy Code: What Will It Cost?
Passive House: A Bit of Overkill

How do you optimize a forced-air system to maintain a green home? Alistair Jackson, LEED AP for Homes Responds: Part I: Distribution

If not installed or maintained properly, forced-air heating and cooling systems can perform poorly, creating air quality problems and unnecessary expense. To optimize a forced-air system, you need to design or refine it to prevent leaks and pressure imbalances, protect it properly during construction (or make sure the ductwork is clean and sound), and use the right filter.

The performance spec of the heat (or cooling) source is also important, but it is critical to address the distribution system first before investing in better furnace and air handler performance. This article is the first of four focused on optimizing forced-air systems on the topics of Distribution, Filtration, Heat/Cooling Source, and Ventilation.

Leaks in the distribution system – the ductwork – can quickly undermine the efficiency of a forced air heating system. Ideally, the ductwork should be air tight and well-insulated. A “duct blaster” test, performed by a qualified technician, is the best way to find out how leaky the ducts are. In new construction, a “total leakage” test can be done at rough-in when all the ductwork is still accessible to measure tightness. If needed, theatrical smoke blown into the ducts can help identify leaks to facilitate sealing. If the ductwork is already hidden, a “leakage to exterior” test will identify how much heated air is leaking outside the building envelope. These are the most important leaks to fix since they represent wasted heat. A qualified home performance contractor (see resources below) can perform these tests, explain what the performance targets are for the home and how the system is actually performing. As a rough guide, the Northwest Energy Star target for new construction – a good benchmark for any home - is 6cfm@50 pascals per 100 sqft of conditioned floor area.

In an existing forced-air system, it can be very difficult and time consuming to access all the ductwork to fix leaks. In addition, old ductwork may be full of dust and other contaminants. These factors might lead you to consider replacing the whole duct system – an often overwhelming proposition with ducts buried in the building structure. There is an alternative: First, replace the accessible parts of the system, often located in unconditioned crawl or attic spaces, where in many homes up to 30% of the heat loss occurs. Second, strategically block and air-seal where ducts penetrate the building envelope and disappear out of sight, thereby ensuring they are enclosed in the building envelope. This can be confirmed with blower door and duct blaster to perform the “leakage to exterior” test mentioned above. (NOTE: If unlined building cavities are used as ducts, these must be lined or ducted)

If the thermal performance of the building envelope is significantly improved through weatherization and/or remodeling, this will affect the whole system.  Reduced heat loss/gain will result in smaller heating and cooling loads.  So a smaller furnace/heat-pump will keep the house comfortable.  Smaller volumes of air can be delivered efficiently through smaller ducts. We will discuss this further in the heating/cooling source article coming up (number 3 of this series).

A qualified technician or HVAC contractor should perform a “Room by Room” load calculation (ACCA Manual J or equivalent) and a duct system design calculation (ACCA Manual D or equivalent). This will show if your existing duct system is appropriately sized for your heating and/or cooling loads – and will inform the design/sizing of a new or replacement system.

You should also consider the path of air from the supply registers to the returns. Obstructions to free airflow along this path, such as closed bedroom doors, will cause pressurization of the bedrooms and depressurization of the core of the house where the return registers are located. These pressure imbalances can cause:

• Reduced supply air flow which may make the room uncomfortable;
• Increased leakage from supply ducts, wasting energy; and
• Most importantly, the risk of back drafting of naturally-ventilated gas- or oil-fired combustion appliances, as well as wood-burning stoves and fireplaces located in the core of the house. The negative pressure sucks flue gases into the living space instead of letting them exhaust to the outside—not a good situation. As a rule, combustion appliances installed inside conditioned space should be power-vented or, ideally, closed combustion.

Pressure imbalances can also cause poor-quality air to be drawn into the house from attics and crawl spaces or force warm, moisture-laden indoor air through leaks into wall cavities, where it may condense against the cooler surface exposed to the outside and cause serious moisture problems. You can mitigate small imbalances by installing return ducts in each bedroom, by installing transfer grills (a small duct often installed above a door connecting it to the next room or hallway) or jumper ducts (a duct that runs over the top of a partition wall, bypassing a bedroom door, for example), or by undercutting doors to allow some air to pass from room to room or to return ducts in each bedroom. A rule of thumb for sizing is one square inch of opening for each CFM of air supplied to the area “behind” the door.

During construction, don’t forget to protect the system from particulate pollutants by sealing supply and return registers and not storing ducts in the construction area before installation. Periodically inspect and clean registers and ducts if necessary.

Performance Testing Resources: To find a qualified Home Performance Testing contractor, check out websites for Building Performance Institute (BPI) or RESNET. If you are located in Washington see Home Performance Washington or Northwest Energy Star.

Alistair Jackson, LEED AP, CSBA is Principal in Charge of O’Brien & Company’s Residential Technical Services, and is a LEED for Homes Rater & Faculty, Energy Star Verifier and Performance Tester,  ARCSA Accredited Professional, and Built Green Verifier. Alistair was also a major contributor to the Northwest Green Home Primer where much of the information for this article originally appeared. It has been expanded upon for this publication.

Did you enjoy this article?  You might also like these Building Capacity Blog articles:
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 2
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 3
Tips for Optimizing Forced-Air Heating and Cooling Systems Part 4
Mechanical Systems and Fuel Choices for the Warming World
Creating Effective Energy Efficiency & Conservation Strategies Part 1
Type of Construction for Passive House System
LEED EB: O+M's Energy Threshold

How can COMMUNITIES accelerate change towards green building? Kathleen O'Brien, LEED AP, CSBA responds.

When serving on a panel for the Living Future Conference last spring, an audience member, noticeably distressed, asked: “How can we move towards sustainability faster? We don’t have time to waste!” Last week, I responded to this question in terms of what an individual can do. As promised, this week, the post focuses on what our communities can do.

Many within the environmental sector respond to environmental problems with: “There oughta be a law.” This is certainly an appropriate response when the desire is for "minimum compliance." With green building we want and need much more than the minimum. We want creative, integrated, and restorative solutions that move towards the ideal of sustainability. In my experience, that requires an approach that allows the interplay of private and public sector partnerships that build market, identifies solutions, and moves us ever forward.

The first step of this approach -- and one that continues to reward -- is education. Government agencies have provided free and low-cost education on environmental issues since the ‘70s, when the EPA and the DOE were formed. Local agencies -- cities, counties, and states -- have followed suit.

Much of the initial education was focused on obtaining industry compliance with (as well as public awareness of) regulations administered by these agencies. Over time, the educational approach has shifted to promoting going beyond code or law, as regulators discovered that the law had quickly become the ceiling rather than the floor -- an unintended consequence.

In the early '90s, when these agencies began to offer education on green building solutions, they realized it would require the cooperation of the design and construction industry -- both in terms of building the market for these solutions as well as building the capacity to respond to this demand. Not everyone understood this, of course. When I was publicizing "Building with Value" in 1993 -- the first green building conference aimed at contractors in the Northwest, I was asked: "Why are you doing this? We'll just tell the builders what to do, and they'll do it!" Fortunately, many regional organizations, both government and non-profit, DID understand the value, and provided enough funding to cover the costs of this conference, helping to set the stage for a vital green building movement in the Northwest.

As time went on, these organizations joined with the design and construction industry to create more and more learning opportunities for professionals and the public, including workshops, demonstration projects, fact sheets, brochures, videos, websites, and more. And now, the educational pathways are robust and diverse. In addition to finding high quality educational resources through the U.S. Green Building Council as you would expect, you can find them through industry groups, such as the AGC, AIA, ASHRAE, or NAHB at the national and local levels. Government entities (EPA and DOE) are still doing good work at the national level; a great example of a local jurisdictional effort is the King County GreenTools Program. And public/private education efforts continue to produce demonstration homes around the country. A must-see example in our backyard is the ZHome townhome project (link) under construction in Issaquah, Washington, which aspires to net-zero energy and carbon emissions, 60% reduction in water consumption, and the use of healthy, green materials. There is no doubt in my mind that the level and quality of educational investment correlates directly with the level of awareness and acceptance of green building principles and practices.

The next step that forward-thinking government agencies have taken is to incentivize green building. This strategy makes doing the right thing "convenient." An example of this is when municipalities provide grants, fee-bates, density bonuses, or streamlined approval process in return for exemplary implementation of green building techniques or standards. Jurisdictions around the country have used this technique to move awareness and acceptance forward to action. It is essential that the incentives are designed to be meaningful. For example, expedited permitting may be an incentive in a hot building market, but not in today’s cool one. Early adopters have been willing to assume more risk and have required less incentive to act. For most of the industry, however, and particularly now when the stakes are so high, aggressive incentives will be needed to offset the risk (even if merely perceived) to provide the comfort level required to spur action.

Another important aspect of designing effective incentives is to focus on performance, rather than prescription. In this way, projects that use the incentives are much more likely to produce the results you are looking for, as well as inspire innovation that can transform building across the board.

Making the wrong thing" inconvenient" to do is the natural next step (and often skipped to my dismay). For example, policy that makes it more expensive to permit a building because it lacks green features or certification or is “super-sized” can be particularly valuable in raising awareness, gaining acceptance, and motivating action. The Washington State Energy Code 2009 (currently suspended but expected to go into effect sometime next year) discourages “McMansions” by requiring additional energy efficiency measures for projects over 5,000 square feet. Other jurisdictions around the country have added requirements or fees to buildings that exceed size limitations or fail to include a particular green feature. (The fees are often used to fund energy efficiency or renewable energy projects.)

Although eager beavers among us would like to do it first…the very last step should be “Just tell 'em what to do.” And even with this step, there is an order to it – apply the mandate inward (to public sector buildings) first, and then outward (to private sector buildings). In the first step, public money is invested to help redirect the economy by creating demand for new products and services – a time-honored practice. It makes a poor case, to say the least, if government representatives are not willing to take the same risk they are asking the private sector to take! Fortunately, we have many examples of jurisdictions that are willing to hold themselves accountable in this way.

If you wait until the market has done all the work it can before crafting and implementing codes, you’ll have already won over most of your constituency. You’ll avoid quashing innovation that provides broad-based benefit. And you’ll avoid the unfortunate circumstance of obsolescing incentives before they've been optimized. Many are unaware that the minute an energy efficiency measure becomes code, utilities can no longer justify grants or rebates for this measure. We have seen this in Hawaii with solar hot water, and I anticipate we will see this in Washington State where performance testing, now promoted by utilities through incentive programs, will become required with the new code.

If you take this incremental approach, you've maximized the joy, and minimized the pain. No one is suggesting this approach shouldn’t be accelerated given the realities we face, nor that there isn’t a place for thoughtfully designed green building legislation. The effort, however, should recognize how people and organizations really change. In addition, regulators need to understand that the building sector is incredibly diverse. Readiness for green building implementation varies significantly with the building sector you are targeting, whether it is residential, commercial, or infrastructure, and varies even further depending on project types within these sectors. And geography matters -- urban locations may be better suited to aggressive change, rural locations maybe not. I prefer regulations that recognize the need to phase change in, allowing the regulatory process to incorporate lessons learned. An example of the latter was the implementation of the Washington Sustainable Schools Protocol we helped develop, where the State Legislature funded pilots first, voluntary participation second, and then applied a mandate (which itself was phased in based on school district size). Even this phased approach was challenging for school districts, but I believe it was much better than an approach aimed at "instant change." (In the land of coffee drinkers, try suggesting that instant coffee is equivalent to that double shot soy latte!)

Communities inspired to become change agents should be constantly vigilant in recognizing where their constituents are relative to the desired change (are they in awareness, acceptance, and/or action?) and provide them with the information, motivation, and tools they need to feel confident as they move along this spectrum of change.

Kathleen O’Brien is Editor of Building Capacity Blog and President of O’Brien & Company, which she founded nearly 20 years ago. She is author of The Northwest Green Home Primer and has consulted on many public and public/private projects aimed at getting green buildings on the ground.

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LEED for Existing Buildings: Operations & Maintenance's Energy Threshold: What does it take to get through the door? Kelly Kirkland, LEED AP O+M, Responds

A prospective client asks: Is it possible for our building to get LEED-EB certified? Although we'd love to get the rating, we're not sure if we'll meet the minimum energy efficiency standard to make the effort worthwhile. How do we find out before we get too far down the road?

KELLY: That's a great question, and you're not alone in wondering about this, because in truth it can be a little complicated.

But first, for our readers who aren’t familiar with LEED for Existing Buildings (LEED-EB), or the Energy Star Portfolio Manager (ESPM), which is the benchmarking tool required by LEED-EB, here is a quick overview:

The LEED-EB rating system recognizes buildings for their ongoing high performance in sustainable operations and maintenance. This rating system relies on another tool, Energy Star Portfolio Manager (ESPM), which was developed by the Environmental Protection Agency (EPA). It’s currently the best available national benchmark for building energy performance. It is built on a baseline of data collected from the Commercial Buildings Energy Consumption Survey (CBECS) which includes a wide variety of buildings, from old to new, and leaky to tight.

One of the key prerequisites of LEED-EB is proving that your building’s energy performance is, to paraphrase, “better than average”. You can use ESPM to compare your building’s energy use with similar buildings. This tool assigns a score (a rating on a scale of 1 to 100). A score of 69 or higher means the building has met one of the eligibility requirements for LEED-EB certification. Simple, right?

The reason it gets confusing is that not all buildings are eligible for a score from ESPM. The basic eligibility requirements are clearly stated on the ESPM web site.

However, there are sometimes complications. For example, some space types have their own additional set of requirements. And sometimes, when combined, the requirements don’t quite work for buildings that otherwise seem eligible. For example, two basic requirements are

1. meeting the minimum square footage (usually 5000 sq ft)
2. having building space types for which there is data to compare to

But if you have a building that is 10,000 square feet, half hotel (5000 sq ft) and half office (5000 sq ft), you won’t be eligible for a score because neither portion takes up more than 50% of the total square footage.

The good news is, even if you’re not eligible for a score on a scale of 1 to 100, you should still be able to use ESPM to get certified under LEED-EB. The LEED rating system has a calculator that allows you to plug in data points generated by ESPM, specifically your “weather-normalized source energy intensity”. Plugging this number into the calculator allows you to determine whether you are “better than average” or not.

There are other options for complying, too. You can do your own detailed analysis of your historical energy use (normalizing the baseline for occupancy changes and weather), or you can do that plus collect data from other comparable facilities. This can take a lot of time and, because these methods are not as reliable, you may find that there are fewer points available.

My best advice is to just give ESPM a try—especially since, starting in 2011, it’ll be required reporting in Washington State for buildings larger than fifty thousand square feet. Enter your space types, energy use, occupancy and other data as accurately as you can. If you don’t see a rating in the upper right, click on the “NA” and you’ll get a custom message that explains why. If the answer is that you are not eligible for a rating, then get your “weather-normalized source energy intensity” from ESPM and use the LEED-EB calculator to get your adjusted benchmark.

Kelly Kirkland, LEED AP O+M and CSBA is a Project Associate at O'Brien & Company and provides technical assistance to the firm’s clients seeking LEED-EB: O&M certification. The firm also provides a LEED-EB: O&M "Lite Bite" to help you get up you get up to speed on the ways you can use this standard to your advantage

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Passive House: Isn’t it a bit of overkill? James Jenkins, Certified PH Consultant responds

Jenny Nakao Hones of Three Frogs Design asks the question: Passive House seems like it could be a great idea for places that have extreme weather conditions, with significant temperature swings. I’m wondering about more temperate climates though, such as the West Coast. Isn’t it a bit of costly overkill? 

Great questions, Jenny. For those unfamiliar with Passive House (PH) it’s a green building standard originating in Germany, gaining popularity worldwide. It’s based on predicted performance and results in very low-energy buildings that maintain comfortable temperatures with minimal input. The name is a bit of a misnomer; the German word “haus” translates directly to shelter or building – not house. So it applies to non-residential projects as well as homes. PH’s technical focus is on Energy and IAQ.

The principles found in the PH Standard actually have deep roots in the super-insulation movement of the US mid-west decades ago. Many of these projects failed because moisture and ventilation were not well considered and the same R-values were used universally, independent of climate. PH has taken the idea and infused it with building science to ensure that the problems of the past are not those of the future.

The beauty of this new and improved approach to passive technology is that it addresses what many believe is the biggest threat we face today – climate change and maintaining a habitable planet – in a way that leverages lessons learned about how buildings actually perform, and provides multiple “side” benefits to the building owner (more on that later).

Achieving PH’s strict energy requirements is typically done through a super-insulated envelope, nearly air-tight construction, and a heat recovery ventilator (HRV) to provide continuous fresh air. There is no prescribed approach beyond meeting the maximum energy consumption targets, however. Katrin Klingenberg, Director of Passive House Institute (US) recently completed a post occupancy evaluation of her personal residence in Illinois. Passive House Planning Package (PHPP), the rating system’s energy modeling software, proved to be accurate within 10% of her actual energy consumption and 70% lower than the typical American home.

In another study of a low income housing project, Katrin concluded that the cost per kWh saved was 7 cents when building to PH standards. By way of comparison, this is slightly less than the cost of purchasing a kWh from the Seattle City Light (around 8 cents per kWh). Thus it is cheaper to save the energy than to purchase it. Bearing in mind that in Seattle energy is relatively cheap today, but isn’t expected to stay that way, the long term cost justification for PH will only get stronger. There are several PH projects under construction in the Seattle area, and like other green certified buildings, reported first costs are all over the map – ranging from 0% to 18%. Given this wide range, it does not seem that PH is the driving force where first cost premiums exist.

Let’s discuss your first concern, whether super-insulation is cost-effective in mild climates. It’s important to keep in mind that the PH system includes little reliance on conventional technologies. This is the key to it being cost effective. We need to insulate passive buildings only to the extent that we can minimize or eliminate the traditional heating and cooling equipment found in typical buildings. Precisely calculated insulation values allow the internal and solar gains in a building to be roughly the same as the heat loss through the walls and windows in any climate. Super-insulation may not be necessary, or appropriate, in all climates. In general, higher indoor to outdoor temperature differentials will require higher insulation values in heating dominated climates, moderate climates such as Seattle might require R-40 walls in a single family residence. (This is roughly twice the Washington State Energy code minimum; in colder climates, you’ll see wall values of R-50, 60, or even higher.)

And let’s not forget windows! Even at their best, windows are the single largest source of heat loss in all buildings. PH requires the indoor surface temperature of a window be 64 degrees F, based on the low design temperature for the climate zone. In the Puget Sound area that’s roughly U-.19. The bottom line is that PH projects in milder climates can use less expensive windows and less insulation when compared to more extreme conditions.

An even more important aspect to PH is air tightness. PH details achieve .6 air changes per hour at 50 Pascals (ACH50). This significantly improves energy savings in two ways, by reducing air infiltration, and by redirecting heated air flow through the HRV where it can be of use.

With proven operational savings and a cost-effective design approach, PH is a financial boon to green designers, builders, and building owners looking for answers in this lean and mean economy. But that’s not all the system offers. There are several additional owner benefits, including:

• Predictable long term ownership cost;
• Comfort;
• Passive survivability in cases of lengthy power outages or energy disruptions;
• Protection against likely carbon taxation;
• Lower replacement cost of mechanical equipment due to less complex systems requirements; and
• Future readiness for net zero energy capability.

Designers thinking about employing PH should know that the modeling protocols for PH are not accepted by other rating systems (such as LEED) at this time. Its proven accuracy suggests, however, that it’s a great tool to optimize designs. Designers will be able to identify the least cost strategies required to meet an energy savings target. PHPP software can be used to find just the right window u-values, insulation R-value, and window placement for your project.

For builders wondering how they can make the case to owners, understand that when we design the envelope precisely and with the goal of eliminating the traditional mechanical system, added insulation and better windows are not added first costs but costs that can be offset. The key challenge to the contractor will be meeting the aggressive air tightness requirements. Even at its best, current practice rarely generates anything below 2.0 ACH50. However, this challenge also serves as a tremendous opportunity for the business-savvy contractor to add value to their building projects. Quality assurance on a PH project is critical. Better buildings will be the result. That means fewer callbacks, and better referrals – as well as experience you can transfer to other projects.

James Jenkins, CPHC, CSBA, LEED AP BD+C, and Homes, is a Project Manager at O'Brien & Company, consulting on residential and non-residential green building projects. He is a Certified Passive House Consultant and currently serves as Vice-President of Passive House Northwest. Linda Whaley provided the construction photo. You can see more in-progess shots at her blog Existing Resources.

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U.S. Coast Guard Leader Builds Sustainable Foundation: Interview with Captain John Hickey

EDITOR: We recently toured the Oahu Sand Island Base where you’ve been Base Commander until recently. We were pretty impressed with the savings you’ve been able to accomplish. What got you started? CAPTAIN HICKEY: I started my Command there in 2007. There were already several mandates in place focused on sustainability – the Energy Policy Act (2005), Executive Order 13423, and the Energy Independence and Security Act of 2007. At the same time the base had seen some action with an Energy Savings Performance Contract, but it left a lot to be done. I felt it was important as the Commanding Officer of the biggest facility in the Pacific to get something going in-house.

And what was that “something?” We enrolled in Hawaiian Electric Company's Demand Response Program "Energy Scout". (Demand Response Programs, or load control programs are not unique to Hawaii; Captain Hickey has enrolled other CG facilities in such programs in California, Baltimore,  Boston, New Jersey, and Virginia.) With the connected load of our ships, we had more than 1 megawatt of curtailable load that we could disconnect if the grid was in trouble. Our incentive for this participation was over $100,000 a year. We used this money to train our crews in energy efficiency and renewable energy. Then we let them go to work looking for ways for the base to save energy.

What did you find?We found lots of opportunities. For example, by de-lamping and re-lamping exterior fixtures, we reduced our consumption for exterior lighting by 80%. We looked for less obvious things to do as well. We found that in some of our vending machines we were spending $4 on energy for every soda we sold! Easy enough, we got rid of the vending machines. We also began promoting commuting by bike (see bike rack in photo), that helps with reducing our carbon footprint, as well as with the weight issue. Furthermore, we improved our HVAC controls and installed several solar domestic hot water systems.

So you were able to really leverage that $100,000 HECO Incentive.Yes, we needed to be creative with our resources, and we certainly made a lot of headway with the HECO money. We also used interns from the University of Hawaii for some of our analysis. One resource we’ve been taking advantage across the board are the National Laboratories. NREL (National Renewable Energy Laboratory), for example, is doing some high performance building training and energy auditing for us; PNNL (Pacific Northwest National Laboratory , is helping us with a REM and coordinating with BPA (Bonneville Power Authority); LBL (Lawrence Berkeley Laboratory) is helping us with our data centers; Oak Ridge National Lab is assisting with compressed air systems, and so forth.

What other opportunities for sustainability have you explored?Well I got my start in the Northeast when the Coast Guard “solar-ized” all our offshore lighthouses. And I’m happy to report that the crew in Hawaii is continuing to take leadership in this regard. Now that I’m stationed in Seattle, I’m focused on how we can maximize sustainability in our projects in the Northwest. As you know, we’re pursuing LEED for Existing Buildings Certification on the U.S. Coast Guard’s Seattle Shore Ops building (see photo). That’s an interesting project, because we have a complicated situation there, both in terms of hours of operation and HVAC equipment, making it a challenge to get the crew up to speed. Turnover is an issue, too. We had someone trained and then they were mobilized to Afghanistan. Frankly, my preference is to use passive, less complicated designs as much as possible; it will make training easier, and won’t matter so much if we have turnover.

What do you think of LEED EB?Actually I like using LEED EB, because it’s a way to get everyone on board. For me, it isn’t just about new construction of green buildings or maintenance of an existing building. It’s about general operations too – for example, environmentally preferable purchasing (EPP), solid waste management, alternative transportation. To use a maritime term, LEED EB makes it an “all hands on deck” situation. LEED EB isn’t difficult; we just have to do it.

What’s next?We’re working on a few things. There’s a pilot program for our training campus in Petaluma starting up later this year that’s going to help us transition from individual buildings to volume LEED-EB certification. I’m very interested in a “fence to fence” approach. And with new construction, we need to focus on getting as many energy points we can get. A LEED Silver rating is the goal, but in some projects there hasn’t been adequate attention to how it’s achieved. We’ll be looking at improving our RFP process so we get what we need.

Are you optimistic?I believe that a lot of our people want to take a sustainable approach; the Coast Guard attracts people who want to do the right thing, and marine environmental protection is a core mission for our organization. We just need to provide the right leadership, opportunity, and power to take the action – and a little creative support, like we did with the HECO incentive and UH Interns. I actually think the bar is set a bit low. We can do this, and it’s more than a nice thing to do. It’s urgent. Our national security depends on energy efficiency and a solid economic base. Sustainability will get us there.

Captain John Hickey, PE is an officer in the U.S. Department of Homeland Security/Coast Guard, recently transferred from the Oahu Sand Island Base to Seattle. Kelly Kirkland of O’Brien & Companyis managing the LEED-EB: O&M certification of the Shore Operations building in partnership with ECH Architectureand USCG Energy Manager Bob Mallahan.

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Cracking the Energy Code: What will it Cost Me? Alistair Jackson responds.

TRAVIS ROHRER OF TOPLINE BUILDERS (http://topline-builders.com/) ASKS: The upcoming change in the Washington State Energy Code is really raising the bar. I appreciate the need to conserve energy, but as contractors, how can we meet the code without losing our shirts?

ALISTAIR: You are absolutely correct about the fact that WSEC is raising the bar in a big way. Washington’s Energy Code has been one of the strictest in the country, and with the changes planned to take effect July 1, 2010 (the WSEC 2009), it will certainly be continuing this legacy. With the current economy and construction market, it’s easy to view this as a big barrier to recovery. However, for the smart contractor, this could actually be an opportunity.

First, let’s summarize the kinds of changes coming up:  The code increases insulation requirements in roofs and some wall conditions, and requires more efficient windows. Under the infamous Chapter 9, it also provides a range of prescriptive options for the additional performance requirement from thermal envelope and infiltration upgrades, to increased equipment efficiency; there’s even credit for smaller than average homes and a “debit” for very large homes.

Perhaps the biggest change the Code offers is the provision for performance testing for both envelope infiltration and duct leakage. For some time, we’ve known that getting a blower door test on a home is at least educational and occasionally a revelation. The result is better upstream detailing and construction management, more comfortable homes and happier customers.

Failing a building inspection is one thing – a finished house that can’t get an Occupancy Certificate until the leaks are found and sealed is a liability nobody wants. Far worse are callbacks from an unhappy general contractor or homeowner. And even worse are lawsuits due to mold or durability issues. For a home to be high performing energy- AND durability- wise, properly sequenced detailing will be key. And frankly that means proactively reviewing your construction process and practices, TESTING the outcome and improving them if necessary. Proactive testing can prevent headaches and save you money in the end, whether you’re talking envelope infiltration or duct sealing. In one of our projects, an HVAC contractor was sealing their ducts with mastic and thought they had Energy Star sewn up until we showed up with the duct blaster. What started as a teaching moment ended with a team of installers signing each new duct system with pride, competing for the tightest system of the month. Despite the “difficult” start to the relationship, Lyle Kargel of Air America had this to say of O’Brien & Company: “The best experience in the 23 years of being a HVAC contractor was working with your group. My hat’s off to your group.” Talk about turning lemons into lemonade!

There will undoubtedly be some upfront costs associated with the Code changes. In a WSU study done for the Washington State Energy Office, Chuck Murray estimates an extra $0.50 to $2.04 per sq. ft. This includes the cost of blower door and duct blaster testing. But if you treat the blower door test as “end of the line” Quality Control (QC), the real cost comes when you get a failure and have to track down and seal leaks in a finished home – we once had a project that had to take out one wall of a finished kitchen to seal up an old sheathing penetration for a range hood that was repositioned; Ouch! The secret to controlling those costs is Quality Assurance (QA) – Identify where your construction system is weak, develop prescriptive steps to fix them, educate your crew, check for implementation, stop work and correct as necessary, learn from the results, update as necessary.

Using this approach, including a pre-insulation air sealing inspection and rough-in blower door test, Dave Brogan of Bellingham Bay Builders (www.bellinghambaybuilders.com) just brought their first LEED for Homes project in at about 0.9ach50. Nice work, Dave!

There’s a learning curve cost with this approach but once you have a system, the cost is minimal. Then the payback comes not only in referrals from comfortable customers with lower energy bills, but in avoided rework costs and reduced callbacks; that goes straight to the bottom line. It’s important to keep in mind the rationale behind these changes. Energy Independence, Climate Change, and Green Construction Jobs. Don’t forget, more jobs mean more people who can afford homes.

Let me close with this. For all the hubbub about increased costs, it’s possible to build a very tight stick-built house (<3 ach50) for the addition of a couple of hundred dollars of caulk and foam. Here’s how: • Hire someone to test the last house you built and identify where the leaks are (Yes – we can do that ;-); • Develop a thorough Quality Management Plan; • Use Energy Star Critical Details and Thermal Bypass Checklist, Built-Green Trade Tips and/or LEED for Homes Durability Plan to help take the fear out of July 1, 2010.

Alistair Jackson (LEED AP, CSBA) is Principal-in-Charge of O’Brien & Company’s residential green building services team. Learn more about O’Brien & Company’s Code Prep Diagnostics and more at www.obrienandco.com/services/green-building-consulting/cracking-the-code-wsec-2009.

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