Davis Construction: La Plata, MD

The attached homes, sized between 1,000 and 1,500 square feet, were constructed with Arxx insulating concrete forms. One-story models fell at the low end of the size scale. All homes were Cape Cod styles on slab foundations. Second story floor framing systems were wood I-joists; the roof was framed with scissor trusses.

Rendering of house

Floor plan

Model house

Whole House Mechanical Ventilation Strategies:

Two ventilation systems were evaluated—a central-fan integrated (CFI) system and an energy recovery ventilator (ERV). The CFI system utilized a four-inch supply duct to bring outdoor air to the return side of the air handler. To avoid pressurizing the home with the ventilation system, an exhaust fan in the bath ran continuously at 20 cfm..

The ERV was a balanced system in which incoming supply air was preheated through a heat exchanger core with outgoing exhaust air. Moisture can also be transferred between the two airstreams with an ERV. .

Fiber Cement Siding:

8¼-inch, dutch lap fiber cement siding was specified as the standard cladding for the homes. .

Tubular Skylight:

A 10-inch tubular skylight was installed in the subdivision’s model home..