October 2006

Energy and Resource Efficient Communities through Systems
Engineering: Building America Case Studies in Gainesville, FL

Leads --  Ken Fonorow (Florida Home Energy & Resources Organization),
Subrato Chandra and Eric Martin (FSEC).

Two builders in Gainesville, FL chose to improve the performance and marketability of their homes taking different paths. A study of each of these builders’ cases details the critical elements of a systems engineering process that has resulted in increased sales and fewer callbacks. Additional benefits these builders realized include enhanced customer satisfaction through improved comfort, improved indoor air quality and lower operating costs.

In the first case, the builder, Atlantic Design and Construction, elected to use an incremental approach towards the process of improvement over time. In the second case, G.W. Robinson Builder, used a comprehensive approach. While both case studies represent two different approaches to achieving the goal of the construction of high performance homes on a community scale, the comprehensive approach reduces ongoing complications and provides a better opportunity to control costs, quality assurance and enhance profits. The comprehensive approach is discussed below.

G.W. Robinson Builder – Cobblefield, Gainesville: Build out 265 homes, 241 built; Turnberry Lake in Gainesville: Build out 186 homes, 30 completed.

In contrast to Atlantic Design’s incremental approach and despite the recommendation of a market survey, it was G.W. Robinson’s desire to build the healthiest, most energy- efficient and “green” subdivision possible for move-up buyers within reasonable financial constraints. Typical home sizes are 2,500 to 3,500 square feet, with a selling price of $300,000 to $400,000. Homes implement properly sized 12+ SEER air conditioners; engineered air distribution system; double pane low-E windows; radiant barrier; air handler located within the thermal envelope; programmable thermostat; cellulose insulation, filtered outside air for mechanical ventilation, and new quality assurance procedures.

While recognizing that a home’s most significant environmental resource impact will be the energy needed for its ongoing operation, this builder also addressed the issues of durability, health, maintenance, landscaping and irrigation. To enhance durability each home is treated with Bora-Care®, a termiticide whose active ingredient is Disodium Octoborate Tetrahydrate (DOT), which is a mixture of borax and boric acid. A 50+ year cementitious lap siding is installed over a continuous drainage plane. The entire exterior of the home receives three coats of paint which carries a ten-year warranty. Thirty-year architectural shingles have been selected.

To help ensure better indoor air quality, low volatile organic compound (VOC) paint is used in the interior, all gas-burning fireplaces receive outside combustion air and all rigid duct board material used in the distribution system is a coated style to help separate the air stream from any raw fiberglass. Where applicable, alkaline copper quaternary (ACQ) wood is used, which is arsenic and chromium free.

After protecting wooded areas whenever possible, homes are landscaped with drought tolerant indigenous species which are grouped according to their watering needs. No islands of turf are created. Irrigation is provided through a municipal reclaimed water system where water that would normally be discharged via a deep well injection system is routed to the subdivision to meet the irrigation needs. It is important to note that this service is being provided to homeowners by the developer for $10 a month while a homeowner who uses the potable water for irrigation often pays $40-50 a month.
This initial broad-based adoption of the high-performance specifications provided the opportunity to develop formal scopes of work for each of the different subcontractors that took into consideration the interrelationship of the different components and trades. At the completion of the framing of the model center at the Cobblefield, a team meeting was held at this venue with the builder, all senior office staff, the project real estate agents and representatives or owners of all subcontractors. The builder’s goals, objectives and expectations were clearly articulated with the opportunity for the team to ask questions.

In spite of the real estate agents’ concerns about the increased price per square foot, this Building America (BA) partner chose to move forward with his vision and was rewarded by market acceptance of his high performance homes. This Building America partner’s success with the program has resulted in an increased level of performance for his latest subdivision, Turnberry Lake, where homes feature 14 SEER air conditioners, 0.93 AFUE sealed combustion natural gas furnaces with variable speed motor located within the thermal envelope, natural gas instantaneous water heaters, and double pane vinyl frame windows with SHGC of 0.28.

All of the homes currently built by this builder achieve a Home Energy Rating System (HERS) score of 88.6 or better and are expected to qualify for the $2,000 Federal Energy Tax Credit. All homes are individually performance tested as part of a commissioning process. These homes are calculated to have whole house energy savings in excess of 30% as calculated by the Building America benchmark methodology.

The complete paper detailing research on both case studies can be seen at: http://www.baihp.org/pubs/aceee_fonorow/ACEEEpaper.pdf


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