The Millennium House: A Strong, Affordable Home for the 21st Century
Is it really possible to design and build an affordable home that costs less than $20 per month to operate, provides a low-maintenance living environment, and is strong enough to withstand the weather in Oklahoma’s infamous tornado alley? Most people wouldn’t think so. But then, retired engineer Don McCarthy isn’t most people.
The 81-year-old McCarthy saw his dream home become a reality thanks to the assistance of Neighbor for Neighbor, the non-profit umbrella organization that brought together the groups and the resources to build the Millennium House on North Wheeling Avenue near downtown Tulsa. In summer 2004, construction was completed on this durable, low-cost, extremely healthy home that was designed specifically for low-income homeowners. The 1,200-square-foot house features cutting-edge technology, structural innovations, and a lot of common sense.
[IMAGE: The Millennium House combines technology, structural innovations and common sense to create model for affordable housing.]To meet McCarthy’s stringent requirements for durability, the house needed a shell with adequate insulation and structural integrity. Built on a concrete slab, the house includes Insulated Concrete Form (ICF) walls, which are constructed with stacked, high-density Styrofoam block and filled with concrete. The ICF provides 12-inch insulated and reinforced concrete walls with an R-factor greater than 30. With energy-efficient windows and the planned addition of R-40 insulation in the ceiling, the house will also exceed ENERGY STAR® specifications.
To ensure that the home was as healthy as possible, McCarthy conferred with the American Lung Association (ALA). Since the concrete-walled structure was exceptionally tight, a consultant from the ALA of Eastern Oklahoma suggested installing a 120-CFM ventilation unit to replace the interior air every few hours. McCarthy incorporated an energy recovery unit into the ductwork to boost efficiency and a filtration unit to enhance air quality. These additions, and the lack of carpeting and foundation plantings within ten feet of the house, earned the home the American Lung Association’s designation of a “Healthy House.”
Besides maximum energy retention, the Millennium House needed a high-efficiency heating and cooling system to limit utility costs in Oklahoma’s blistering summers and icy winters. McCarthy chose a geo-source heat pump. With expertise from the Mechanical Contractors Association of Eastern Oklahoma, two 200-foot wells were drilled in the backyard to accommodate the geo-source unit. Together, the energy-retaining IFC walls and state-of-the-art HVAC equipment brings the home’s utility costs to less than $20 per month.
To weather life in tornado alley, the Millennium House’s walls are tied to the concrete slab and footings with No. 4 rebar on 4-foot centers. The roof trusses are also secured to the walls with hurricane straps. The structure can withstand an F3 tornado and winds up to 205 miles per hour. But in case of a particularly fierce Oklahoma twister, the home also features a safe room built to withstand F5 tornadoes, which can generate winds of more than 260 mph. To meet requirements of the Americans with Disabilities Act, the safe room-like the rest of the home-is wheelchair accessible.
Fire safety was an important issue to McCarthy, who chose electric over gas to make the home more fire retardant. The use of nonflammable materials-the ICF walls, steel studs, and an ancillary steel framework-also contribute to the safety of the home.
To control costs in the construction of the Millennium House, McCarthy solicited funds from multiple non-profits and recruited a lot of volunteers. He also built the house on inexpensive property. The house is on one of five lots he owns that he purchased about 3 years ago for $3,000. Because of these cost savings, he estimates the price tag of the finished home will be about $62,000-some $45,000 under market value.
But for now, the Millennium House is not for sale. Researchers with the University of Tulsa and the American Lung Association will be conducting tests on the home’s performance. The house is also serving as a demonstration site and meeting facility for industry professionals.
McCarthy is hopeful the Millennium House will not be the last of its kind in Tulsa. In 2003, voters approved a community improvement plan called Vision 2025, which includes a measure seeking to replace the 6,300 sub-standard moderate- to low-income houses in the city. That would require the city to build or remodel 300 units per year to accomplish its goal-a golden opportunity to expand the impact of innovative housing technologies on the quality of life. McCarthy hopes the city will use the Millennium House as a model for new construction.
