CREAGAN MESINA DETAILS
Energy Conservation and Efficiency: Designed for clients professionally engaged with the technology and computer industries, this house uses both passive and technology-intensive strategies to cutback or eliminate gas and electric bills. These strategies were developed early in the design phase to assure that the building would perform well as a system.
Passive strategies include: very high insulation values and low air infiltration, large windows and living spaces on the South side of the house and small windows and storage on the North as a buffer. A skylight at the highest point in the house both provides daylight and stack-effect ventilation on hot days. Dormers with high windows also ventilate and daylight each bedroom. The furnace size and the duct layout were designed by Sustainable Spaces to optimize performance. There is no air conditioning; good ventilation and good insulation obviate its need in this climate.
Active strategies include: A 7kW photovoltaic system, a solar hot water system with recirculating hot water, 2 whole house ventilation fans in the attics and destratification fans in the main two-story space, and a fresh air intake.
Materials and Resources: Resource efficiency played a key role throughout the design and construction of this house. The existing house was carefully deconstructed. All of the deconstructed framing lumber was saved on site and reused throughout for trim and other millwork. The leftover wood was sold to other builders. During construction, a comprehensive waste management plan generated 60% recycling of construction waste.
Materials choices for construction also significantly reduce the building’s ecological impact: all concrete is 50% flyash substitution—with 110 yards of concrete in the project, this alone eliminated 34,100 pounds of carbon emissions from the project. All of the insulation is blown-in, damp-spray, cellulose insulation—made from used newspapers, cardboard boxes and phonebooks. Cellulose insulation not only is made from post consumer waste, but it requires only a small fraction of the energy to manufacture compared to other insulative materials like fiberglass and polyurethane.
Ninety percent of the framing lumber and all of the wood flooring is FSC certified sustainably harvested. The flooring is harvested in northern California and milled by a small local mill. The wood is used more efficiently as well with the framing at 24” on center. Larger pieces of wood are engineered lumber and the floor and roof rafters are engineered lumber I-joists. Two-thirds of the siding is durable and resource efficient Hardi-plank.
Indoor Air Quality: As one of the clients suffers from asthma, indoor air quality was a significant factor in the design. There are no wall to wall carpets. All of the finishes installed in the house are low/non voc and many are also low/non toxic—for example green seal approved American pride paint and natural linseed oil based finish from Bioshield on the trim. All of the cabinet boxes are made from wood with no added formaldehyde. The insulation is blown-in cellulose which is non toxic and does not off-gas carcinogenic formaldehyde or other toxic chemicals. The energy efficient design reduces the need for heating and eliminates the need for air conditioning, both of which can irritate asthma sufferers. A whole house vacuum was installed as well to minimize dust and other allergens. A fresh air circulation fan is connected to the forced air ductwork to provide 1 fresh air change every 3 hours.
Construction by Ian MacLeod
Photographs by Leger Wanaselja Architecture and Ian MacLeod