TechPractices: FBC Infill Housing, Louisville, KY

PATH's Technologies in Practice are large scale housing projects throughout the U.S. where innovative technologies are being installed and used. Information is presented from the viewpoint of builders and remodelers who can use these examples as models for projects of their own.

Summary

A for-profit developer in Louisville, KY is providing affordable infill housing in tough neighborhoods, and they're selling. Durable yet inexpensive, these houses are planned with energy- and cost-saving features that make them affordable to would-be home buyers with marginal resources. Technically, the homes feature structural insulated panels (SIPs) prefinished with fiber-reinforced drywall that allow rapid assembly. Innovative plumbing and heating equipment are also used. Financing and maintenance programs associated with the project help the buyer with housing costs.

Details

The developer, FBC, has built 20 single-family houses so far on scattered sites around Louisville's inner city. The two-story houses are offered in two models, 1,152 sf at 16 feet wide by 36 feet deep, and 1,488 sf at 24 feet wide by 32 feet deep.

The SIPs are manufactured by FischerSIPS, who is also acting as the developer, and comprise the exterior walls of the houses, with sheathing on each side of a core of foam insulation. Because SIP sheathing is structural, it is normally made of plywood or oriented strand board, which must be covered with gypsum board on the interior side. FBC avoids this extra step by using 'Fiberbond' fiber reinforced gypsum instead of wood panels. Fiberbond is strengthened with cellulose layers to achieve axial load capabilities. This eliminates most of the on-site drywall application. FBC says these panels reduce erection time by approximately 50% compared to stick-built construction, in addition to providing superior thermal qualities. The SIP manufacturer is local, reducing transportation and coordination, further cutting costs. Another advantage of this SIP system is the large panel size. At 24 feet by 8 feet, the panels allow for fewer joints and simplify construction.

The supply plumbing utilizes a plastic plumbing manifold system with a non-jointed, flexible run from the supply manifold to the fixture. The manifold allows plumbing installation by non-skilled workers, which should save costs. The HVAC system relies on a pressurized ductless plenum return. An "Aquatherm" air handler/heating and cooling coil with a thermostatically-controlled pump allows the water heater to provide space heating, similar to a combination air handler/water heater. By integrating the domestic hot water and space heating systems, added efficiency results in energy savings.

Installation/Construction

The homes were designed for narrow urban infill lots, common in most U.S. cities. Envelopes of large panels are quickly assembled on the foundations and clad with either vinyl siding or brick. Covered porches are then added.

The developer plans to convert housebuilding operations to a modular SIPs system by the end of 1998. The house would be trucked to the site in several prefabricated sections. This system would make it one of the first modular plants basing its production on structural insulating panels.

Benefits/Costs

While these homes sell for $62,900 and $72,900 -- only 41% and 48% of the median for the area -- many potential buyers need assistance. The builder's "rent-to-own" option allows a buyer to rent the house, for perhaps a year at $500 a month, with a portion of the rent going into escrow toward the down payment, which is typically 3% of the cost of the house. The buyer currently can take a year to improve his/her credit rating and six months to close on the house. FBC claims that the strength of the program lies in its providing for the large local housing demand while allowing for the many with poor credit to qualify.

The rapid assembly system using drywall SIPs helps keep costs down. The developer stresses, however, that these are not budget-quality houses. The panels do not compromise quality and result in true and level surfaces. SIP construction is quite strong and able to resist the range of weather-related assaults that frequent the area. FBC believes energy savings for these houses to be in the 30% to 50% range, due mostly to the reduced infiltration/exfiltration and more continuous insulation that the SIPs afford. The Aquatherm air handler allowed for the elimination of a separate furnace, resulting in cost and energy savings. Likewise, the pressurized supply plenum eliminates most ductwork.

Code/Regulatory

The local code officials had initially questioned the use of the water heater for space heating. They were concerned that the domestic hot water might be contaminated from circulation through the heating coil. The developer showed literature illustrating that the hot water is used for heat exchange but does not exit the system as domestic hot water. The city has assisted the developer in assembling the sites. The county and state governments have also made a homeownership counseling program available to the development.

Feedback

The 20 houses in the first phase have been completed. Although FBC planned to build 50 houses per year, the area's housing market is slowing down, and the new goal is to build 15 to 20 per year. FBC estimates the plant is adding 60 to 70 jobs in the area.

The homes have received a Five-Star and Five-Star Plus rating from the EPA Energy Star Homes Program. The developer was one of four companies honored with the "Building Innovation for Homeownership" program from the U.S. Department of Housing and Urban Development.

Contact(s)

Do you have a specific question? Try the contacts listed below:

FBC, Inc., FischerSIPs Incorporated
1843 Northwestern Parkway
Louisville, KY 40203
502-778-5577

Structural Insulated Panel Association (SIPA)
P.O. Box 1699
Gig Harbor, WA 98335
253-858-7472

Energy Star Homes Program
U.S. Environmental Protection Agency
401 'M' St., SW
Washington, DC 20460
888-STAR-YES
http://www.energystar.gov/homes

Aquatherm
First Co.
8273 Moberly Lane
Dallas, TX 75227
214-388-5751
http://www.firstco.com