High Performance and Durability Homes At Market Prices
Weiss Building & Development LLC introduces yet another first of a kind project in Illinois by completing the first DOE (US Department of Energy) Challenge Home in the state. Challenge Home is the DOE’s new program that certifies homes to not only a high level of energy efficiency, but also addresses comfort, health, quality construction, durability, and advanced technology. Challenge Home also requires that homes be net zero ready on top of their stringent energy requirements.
This new custom residence at 4711 Northcott in Downers Grove, also received NAHB Green Building Emerald, their highest green certification level, EPA Indoor Air Plus, and is the first third party certified green home to be built in Downers Grove. This home offers a great case study into the fact that healthier, very efficient homes, that are sustainable and built to a high level of building science can be done at market prices. This 3600 sq ft home was completed for less than $140 per sq ft, proving that “green homes” do not have to cost more than code built homes. Included in this modest budget was an extensive underground storm water system, and 35’ deep caissons for a foundation due to soil conditions and lot elevations.
Part of the final performance testing of this home was our third party testing. We tested the home for duct tightness, air tightness, and indoor air quality. Our final numbers for the blower door test on this home were 1.25 ACH@50 (60% better than Energy Star 3.0 requirements) which with our insulation values, mechanical systems, lighting, and appliances led to a HERS score of 35. HERS is a home energy rating, and this score means that this home was 65% more efficient than a code built home.
Beyond just being an energy efficient home, this home takes a holistic approach to green. Health is a major priority for all of our construction, so we sourced materials from start to finish that were third party certified for indoor air quality such as GreenGuard Gold (which used to be GreenGuard Children & Schools). We also use an ERV to exhaust stale air and bring fresh air into the home while also recovering the energy from the exhaust air. There is also a whole house air cleaning system attached to the ductwork that does electronic air cleaning to a MERV 13 level.
The comfortable nature of a green home is something that is often overlooked in a green high performance home. Because we have paid such close attention to air sealing, and using high efficiency windows there are no uncomfortable drafts in the home. This home also contains return air in all rooms except for bathrooms, laundry, and the kitchen. This helps to keep air circulating throughout the house to keep temperatures more stable throughout.
Water efficiency is also important from a sustainability perspective. All of the toilets were Water Sense rated dual toilets, and the faucets / showers are all low flow Water Sense rated fixtures. This efficient plumbing fixtures all leads to substantial less water consumption and will help to save money on water bills.
Building science is a major passion of Weiss Building & Development. All flashing systems, which promote drainage of water on the roof or siding away from the home, were designed and built to the highest level of building science, assuring the clients that they will not have roof, window, or wall leaks. In fact, Weiss Building & Development stands behind this with a 10 year warranty on any leaks in their assemblies, knowing their details are done to the highest level. The roof has flashings around the entire perimeter, as well as around any penetrations. These penetrations are actually double flashed with a self adhesive underlayment on top of the flashing system to further protect it. The walls were built on a rainscreen. Outside the plywood sheathing is 2 inches of exterior foam, which helps to reduce conductive heat loss (AKA thermal bridging). Then the home is wrapped in a weather resistant barrier, with all seams taped and flashings integrated into this layer. The siding is actually installed ¾” from the weather barrier on furring strips, with vents at the top and bottom of the wall. This allows for any moisture that finds its way behind the siding to drain via gravity and shed away from the home with a kickout flashing at the base. Any residual moisture will dry via convection loops through the venting system. This is done because it drains moisture behind the cladding (which water will find its way behind any type of exterior cladding), and allows that draining to freely happen. If siding was attached directly to the wall, the pressure of that would drive moisture through any holes or nail holes from siding. Without pressure that moisture freely drains. This building science ensures this home is much more durable due to this detailing, and will last longer. The siding used has a 50 year warranty on the product and 30 on the finish, but this installation will prolong the life of the finish because of the drying out potential as well as the even temperatures on both sides of the product. Weiss Building & Development believes the lower maintenance a home for the owners, the better.
Other finish highlights of this home include custom cabinets with slow close adjustable drawers and doors, that contain no added urea formaldehyde, and are finished with water based non-toxic finishes. The bamboo floors are sustainably harvested, are 154% harder than red oak, and have a 10 coat finish to protect the durability of the finish as well as the impact resistance of the wood. The finishes meet European air quality standards, and contain no added urea formaldehyde. The Certainteed Air Renew drywall actively absorbs, breaks down, and stores VOC’s and –aldehydes as non-volatile. Studies show this drywall actually actively improves air quality. Most of the lighting in the home is LED, with some CFL fixtures. The 96% efficient variable speed furnace, and 17 SEER AC unit help to keep the home comfortable and efficient, with the addition of the Nest Thermostat that learns owners behaviors for hands off programming. All of the insulation in the home meets GreenGuard Gold standards for indoor air quality as well, as does the drywall, tile backer board, tile mortar, caulks glues, stains, and drywall finishing products. The tile grout used is epoxy based that never requires sealing or maintenance while also offering stain protection.
This home built by Weiss Building & Development and designed by Tom Bassett Dilley Architects exemplifies how you can design and build a high performing, healthier home while dismissing the notion that ”green homes” have to cost a lot more. It also helps to illustrate that quality claims have to be quantified and qualified, and currently green certifications are the only third party quality stamp available for home buyers. Green is efficiency, durability, comfort, indoor air quality, but ultimately it is Third Party Assured Quality!