How to Build an Eco-Friendly Custom Home

Rear exterior image of a custom home from Regency Builders

Photo courtesy of Regency Builders

Building a custom home? In addition to fitting your lifestyle dream, would you like that home to also be eco-friendly? Would it be comforting to request a sustainable design that can make up for the typically larger carbon footprint of a custom home? Perhaps you’re environmentally conscious and simply like the idea of “green” building. Or, maybe you see the potential financial return of energy-efficient construction.

According to custom home builder Jon Schoenheider, owner of Regency Builders Inc., Milwaukee, Wis., there is no “maybe” among today’s home buyers. “It’s become recognized that eco-friendly construction is no longer an option,” he says, “but a necessity when building for a custom home buyer.”

Here’s what you should do to ensure your beautiful new home is constructed as sustainably as possible:

1. Ask your building team about their energy audit process

It’s important to make your builder and architect aware from the get go that building an eco-friendly home is a top priority, he says. The question then becomes just what constitutes an eco-friendly home? What should you ask for? What construction techniques, products, features, and building systems can best reach that goal? How can you evaluate the eco-friendly capability of your potential builder?

According to Schoenheider, a key indication of a savvy, eco-friendly builder is whether or not that builder has an energy audit program.

For example, Regency Builders uses an independent firm to test the performance of each home at three construction stages. Studies include blower door fan tests and use of an infrared thermal Imaging gun to spot and have air leaks repaired. These tests, he says, cost about $1,200 per house.

  • Pre-construction test gauges potential energy efficiency performance of computer modeled home.
  • Pre-drywall test evaluates air tightness, ventilation capacity, and combustion safety of the home.
  • Performance test checks mechanical systems and the air leakage integrity of windows, doors and attic insulation.

“Thanks to these tests we have embraced better [construction] technology,” says Schoenheider. “In the past, for example, we spray foamed the entire house. Now we blow insulation into the wall cavity and then have the pre-drywall energy test done. We always fail this test in 15 or 20 locations where spray foam, caulking or blocking is needed.”

In addition, it helps to have a team that embraces research, i.e. job site managers and trades people that, when putting up Tyvek or installing windows, look for problem areas they may not be able to reach once the house is closed up.

“If your builder does not have an energy audit program,” Schoenheider advises, “I would pay to have my own audit done on the house prior to drywall and then point out problem areas to the builder.”

“Five years go an energy bill for our typical 4,500 square foot Wisconsin home would have been about $600 per month,” according to the builder. “The monthly energy bill for a similar house today would only be $275. So, we have saved the buyer $3,800 a year.”

Majestic exterior image of a custom home by Regency Builders

Schoenheider from Regency Builders selects features based on their return on investment. Photo courtesy of Regency Builders. 

2. Ask about products and materials that will be used in your home

Schonenheider bases his selection of green building products or methods on their environmental impact, impact on buyer health/safety, and, importantly, the item’s Return on Investment or ROI.

“I like to buy on value,” he explains. “If something pays itself off in seven years or less, I use it or highly recommend it to our clients. For example, in Wisconsin we are only required to have R5 insulation along the foundation and only half way down. We found putting R10 foam insulation on the outside edge of the foundation all the way from the footing to the wall has a solid payback in 3 ½ years. So, that’s our norm.”

Another example: Schoenheider recently replaced his own old HVAC system with an unlimited variable pulse furnace and immediately noticed the improved comfort level. Better yet, with the new furnace his energy costs dropped from $755 to $500 a month. A variable speed furnace is now part of the firm’s energy package.

Great room in a grand custom home built by Regency Builders

Some custom home builders, such as Regency Builders, conduct energy audits at three construction stages. Photo courtesy of Regency Builders

3. Ask to see an average monthly energy bill from the builder’s typical homes

Another way to quickly evaluate the sustainability capabilities of a local builder, says Schoenheider, is to simply “ask to see the monthly energy bill for one of their typical homes. Or, ask one of their buyers what their energy bill has been for the last six months.”

Additional Questions to Ask Your Custom Home Builder

Besides energy efficiency, building an eco-friendly home involves providing indoor air quality, effective moisture control and the use of sustainable products and building practices. To evaluate your proposed custom home architect and/or builder on their capabilities in this area, try asking your builder and architect the following questions:

Will the design of your home be sprawling or compact (the latter style will reduce the home’s interior heat loss and environmental impact)? Will the home be oriented to capitalize on daylighting and maximize passive solar heat (i.e. windows that face within 30 degrees of true south)? Will the designer/builder control passive solar heat gain in summer by planting trees in front of windows or by adding sun shades, awnings, or a large roof overhang?

What will be the thickness and R-value of the insulation provided? Does the builder use 2”x 6” or double wall construction? Will the building envelope (i.e. exterior wall) be thermally sealed with continuous insulation, house wrap, and air and moisture barrier membranes? Do construction details work to close up all the openings and penetrations in walls and roof and use spray foam insulation on cracks to reduce air leakage? Will hot water pipes be insulated?

Will a “cool” roofing product (such as slate, terra cotta, white tiles, or special membranes) be specified to reflect the sun’s energy in summer and reduce cooling costs?

Does the design call for the inclusion of energy-efficient ENERGY STAR windows, high efficiency doors with proper weather stripping, energy-efficient lighting (LEDs or CFLs), and energy efficient appliances?

Do plans demand a high-efficiency HVAC system with programmable thermostat, natural ventilation, heat exchanger or a heat recovery ventilation system or an air-source heat pump? Are there options for the use of alternative or renewable energy sources?

Is attention paid to reducing water usage? Are their Low-flow plumbing fixtures and an Energy Star rated washer? Is the water heater properly sized? Can the builder provide a tankless water heater or, perhaps, a gray water irrigation system or drains/gutters that collect rainwater to irrigate landscaping? Have they considered xeriscaping (a landscaping technique that uses native plants and rock to minimize water use)?

Will the home use other sustainable building products that require less energy to produce, are produced locally, are durable and require less long-term maintenance – such as certified sustainable or reclaimed wood, sustainable flooring products (like bamboo, cork and linoleum), recycled steel, insulation made from old blue jeans, and/or countertops made from recycled material? Are low VOC-emitting materials specified, especially with cabinets, carpeting, glues and paint?

Top Four Eco-friendly features in Custom Homes

Custom builder Kim Hibbs, owner and general manager, Hibbs Homes, St. Louis, MO, agrees regarding the increasing importance of sustainable and energy-saving feature and techniques among custom home buyers.

“Eco-friendly design has become more and more important every year,” Hibbs says. “More consumers understand it and ask for a home that performs efficiently. Of clients that come to us, a good three-fourths are already thinking in this direction.”

Hibbs builds true custom, infill homes from 3,000 to 10,000 square feet with a price point of $500,000 on up. “Our sweet spot is between $700,000 and $1.5 million and we’ve done everything from Frank Lloyd Wright styles to Italianate designs,” he says.

Hibbs is an ENERGY STAR® and RESNET Energy Smart builder. [See related article: Six Steps – Five Phases to Building a Custom Home.] The typical HERS score (a Home Energy Rating System by RESNET) for a Hibbs home is 52 – making the homes 52% more energy efficient than a standard new home and over 80% more efficient that the average resale home.

Hibbs rates the top features of an eco-friendly home as follows:

1. Windows. “Without a doubt,” Hibbs says, “the number one sustainable home feature is windows. Make sure you have a good quality, ENERGY STAR® rated window that is right for your climate zone.

2. HVAC. “Number two is the HVAC system. It’s critical that you have an HVAC system that’s efficient. This also involves using variable speed blowers, sealing your ductwork, and using upgraded filters.

3. Insulation. “Another critical component is insulation.” Hibbs suggests a combination of foam, blown in blanket insulation and a very through caulk and seal package.

4. Lighting. “Finally,” Hibbs advises, “make sure your lighting and appliances are energy efficient and Energy Star rated.

An Example of an Eco-Friendly Custom Home Package

Regency Builders Inc., Pewaukee, WI, offers custom home customers a host of energy saving and sustainable features, including:

  • Framing consisting of 2”x6” exterior walls; wood “I” joists with less wood fiber than conventional lumber joists; L/600 or higher floor calculations for stiff floors; and LSL or LVL studs for exterior tall walls. Lumber products use low-emitting, safe resins and do not add urea formaldehyde.
  • Treated engineered wood, factory-primed LP SmartSide ® siding.
  • High performance wood and fiberglass frame Marvin windows.
  • Roofing that offers 100% non-prorated umbrella warranty coverage for 20 years, plus a 130 MPH wind warranty, with shingles warranted for as long as you own your home.
  • Insulation, including: 3” closed cell spray foam insulation at box sill and band joist area between floors; R-23 high-density blown in fiberglass insulation at exterior 2”x6” walls; R-19 batt insulation at garage walls; R-50 blown insulation at garage ceiling; R-50 blown insulation at accessible ceilings; R-10, 2” rigid foam insulation from footing to grade on foundation walls.
  • Completely weather-stripped and thermally-insulated garage doors with CFC free insulation and energy efficient door opener.
  • Drywall manufactured with 100% recycled paper with drywall debris recycled for agricultural use.
  • Zero VOC interior paint and carpeting.
  • Multi-zone HVAC system, high efficiency, multi-stage variable speed furnace, programmable thermostats, and media air filters.
  • Energy efficient CPVC/PEX water piping, a hot water recirculating water line with pump, and a high efficiency water heater.
  • A pipe from drain through roof with an in-line attic fan for radon mitigation.
  • LED lighting, occupancy sensors, lighting timers and controls, and a central vacuum system.
  • Maintenance free deck.

Roy Diez is a freelance writer and marketing professional specializing in the architectural, building and construction industry. He is a former editor-in-chief of Professional Builder magazine.

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