Tasked with creating a nearly zero-energy house in fickle Midwest climate conditions, architect Dominique Davison searched for a balance between an ultra-tight building envelope and the clients’ request for plenty of natural light and ventilation.
For the suburban infill project in Leawood, Kansas, Davison relied on a combination of R-40 SIPs construction, plentiful R6 windows, radiant-heat floors, and a large solarium designed to be closed off from the rest of the house during extreme temperatures. High ceilings and a circular floor plan add to the feeling of openness.
“The clients wanted to get as close to net zero energy as possible but at same time create a bright, open space with a lot of light,” explains Davison, principal of Kansas City-based Davison Architecture + Urban Design. “We were also trying to keep the footprint smaller while making the house feel bigger.”
For maximum sunshine, Davison oriented the main living spaces to face south and placed the garage on the north to help shelter the living spaces from cold winter winds. In addition, the 2,520-square-foot home taps into solar and geothermal power for nearly non-existent energy bills.
The LEED-Platinum project started with a sustainable teardown of the original 1960s home, a dark and outdated ranch. Due to a compromised concrete foundation, the structure was not livable but the clients were committed to thorough deconstruction. More than 80% of materials were recycled or repurposed through the local Habitat ReStore, Davison says, including roof tiles, windows, doors, light fixtures, casework, fixtures, appliances, flooring, and trim.
In addition, the cracked, leaking foundation walls, brick chimney, and basement slab were crushed on site and reused to create a gravel-type mix for backfill drainage of the new 30% fly ash concrete foundation.
The home’s geothermal heat pump from Water Furnace provides heating, air conditioning, and hot water while using about 30% less energy than a standard heat pump and saving about 50% of energy costs over standard furnace systems, Davison says. A 4kW solar panel system from Eagle Roofing, integrated into the concrete tile roof, provides much of the home’s energy needs, and “the clients really liked the look of it,” says Davison.
The owners also adore their 390-square-foot enclosed sun room, which allows them to relax and enjoy nature sans mosquitos, Davison says. Windows across the bottom open for extra ventilation in mild months. In the summer, 3-foot-deep custom exterior awnings and careful orientation keep the sun under control and low-E, argon-filled windows and ceiling fans help to keep heat gain to a minimum. On sunny winter days the room acts as a solar collector but when it’s too cloudy and cold, the homeowners close off the space from the rest of the house with folding doors.
Constructed by Homoly Construction, the house cost a total of $770,000, including the renewable energy systems. Other sustainable products include:
--Thermocore exterior wall, floor, and roof framing systems
--ProGreen low-VOC paints and primers
--77% recycled granite countertops in the master bathroom and kitchen
--a rainwater catchment system, which provides irrigation for low-maintenance native plantings
--a detailed tree protection plan