Builders, architects, urban planners, and sustainability experts held a design charrette on Wednesday, Oct. 24, to come up with floor plans, construction processes, and product suggestions for Concept House Charleston, in South Carolina, the second PATH Concept Home and the first in the Southeastern U.S.

PATH is a program run by the U.S. Department of Housing and Urban Development (HUD) and is a public/private partnership of home builders, manufacturers, researchers, professional groups, and federal agencies that address housing needs.

The first PATH concept home, built in Omaha, Neb., focused on innovative construction techniques that cut cycle time and improve durability. It also emphasized flexible systems to meet the specific needs of homeowners, such as movable interior walls to respond to family changes.

The Charleston house will showcase innovative products and systems that produce a cost-effective, efficient, sustainable house. Because of its location near the Atlantic Coast, this house also will focus on disaster resistance. While hurricane protection will take top consideration, the house also will be designed to resist seismic activity. "Charleston had a devastating earthquake in the 1800s that almost destroyed the entire city," says builder Hank Hofford, president of Bennett Hofford Construction in Charleston.

With year-round humidity, termites, a high-wind zone, and a risk of flooding, Charleston is "a very interesting area to build in," says Jamie Lyons, project engineer for Newport Partners, the Davidsonville, Md.-based project management firm for Concept House Charleston.

The distinction of a PATH concept house from other show houses is that the project goals drive the technology that's used in the house, Lyons says, as opposed to a show house that shows off the latest and greatest products. "We'll have a little glitz in there, but far, far less than the typical show house," Lyons says.

The goal of Wednesday's charrette is to complete the floor plan and the elevation, with "some feel for the sustainability features," Lyons says. The day will include two tracks- a design track for the architects, including project architect Mark Bombaugh from the Silver Spring, Md.-based firm of Torti Gallas and Partners, to actually draw the plans, and a sustainability track "where the technology-oriented folks will look at how we'll meet those goals."

The plans are scheduled for completion by February 2008. Construction should be finished by fall of the same year. Once finished, the house will be open for tours for six months before it's put on the market for sale.

The design of the 2,400-square-foot, three-bedroom house will be consistent with Low Country architecture, Hofford says. Low Country plans incorporate such features as wide covered porches, large front windows, and open floor plans. Beyond that, "we've tried to keep an open slate," Hofford says. "Everybody is bringing floor plans they like for us to look at."

The participants in the charrette also have been asked to bring "one specific product or building system they thought should be included in a green house," Hofford says. The energy-efficiency goal for the house is a Home Energy Ratings System (HERS) index of 60, which would be 40 percent more energy efficient than a current home built to code.

Already high on the list of innovations to be considered are tankless hot water heaters, photovoltaic power cells, and water recycling for landscape irrigation. "This house, by default, will meet LEED certification," he says.

For more information about PATH's concept homes, visit www.pathnet.org/concepthome.

Project parameters and timeline for PATH Concept House Charleston

PATH Concept Home II, being built in Charleston, S.C., will present a stylish, cost-effective, and durable home with a healthy and flexible living environment. The program objective is to design, build, evaluate, and demonstrate America's second Concept Home, creating a vision for the future of home building that resonates with both builders and buyers.

The purpose of this building program description is to describe the basic design and technology parameters for the house. The program will inform the October 2007 design charrette, which will largely define the home's design.

Building Systems: The design will ultimately drive technology decisions, although at the charrette one breakout group will discuss out-of-the-box technology ideas brought forward by charrette participants.

Site: The home will be built on one of a few possible lots, with the exact site being selected prior to the design charrette. All lots are generally level. Side-to-side lot dimensions are: width about 75 feet and depth around 130 feet for all the potential sites. The long axis of the site runs north-south, with the front of the house facing directly north.

House Type: 2 feet to 3 feet raised foundation typical (piers or crawl) although a slab foundation possible on this site; could be story-and-a-half or two-story; the minimum size for first level is 1,800 square feet per the architectural guidelines.

Set Backs: Side - 15 feet; Front and back - 25 feet

House Size: Single-story home minimum is 2,200 square feet. A two-story home minimum is 2,400 square feet with 1,800 square feet on the first floor. We will design a base plan of 1,800 square feet that includes options to easily capture or increase square footage to 2,400 square feet. The Concept Home built will be the 2,400-square-foot model that has exercised the pre-designed options.

  • Exterior Style: Southern vernacular architecture
  • Roof: Architectural shingles, copper standing seam, slate, metal 5V crimp, cedar shake
  • Siding: Cementitious composite shingle and siding, red cedar shake, board and batten. No aluminum or vinyl siding, soffit or fascia
  • Foundation: Brick, tabby or stucco
  • Chimney: Masonry or stucco, with windscreen or chimney pot
  • Glass block: Prohibited
  • Skylights: Prohibited

    • Garage Type: Detached, alley-fed

    Driveway: Surface may be concrete, oyster shell or salt-cured concrete, asphalt, and permeable.

    Spaces: To meet square footage goals, it's envisioned that we won't have formal living or dining but rather address some of these functions with the flexibility theme; three bedrooms, 2.5 baths

    Accessibility: Features such as wider doorways, larger landings, and blocking for future grab bars. A zero-step entry option should be possible and presented in the base plan and alternative floor plans configuration drawings. Accessibility strategies are being pursued to provide built-in flexibility to the homeowner, not to achieve a FHA or universal design home status.

    General Amenities:

  • Wrap-around porch: 8 feet minimum front and 10 feet minimum back
  • Fireplace
  • Overhangs (for design as well as energy-efficiency purposes)

    • Energy: All-electric house; with option for propane tank

    Preliminary Technology Selections with Design Implications:

  • Seasonal shading as a design feature
  • Standing seam metal roof
  • Centralized utility zone to consolidate and simplify mechanical systems
  • Photovoltaic and/or solar hot water systems that optimize cost versus benefits
  • Energy dashboard for the home that shows real-time consumption, carbon footprint, etc.
  • Hybrid-ready carriage house, which contains photovoltaic array that can power a plug-in hybrid or supply energy to the home - blending tradition with innovation
  • Conditioned crawlspace (not ventilated with outdoor air)
  • Conditioned attic which is not ventilated, but is instead insulated at the roof line

    • Schedule:

    The preliminary schedule for the project is detailed below:

  • Design charrette - Oct. 24, 2007
  • Design refinements and selection of building systems -- October-December 2007
  • Construction documents and specifications -- January-February 2008
  • Plan unveiling at 2008 International Builders' Show - February 2008
  • Groundbreaking event - March 2008
  • Begin construction -- March 2008
  • Complete construction -- September 2008

    • Source: Newport Partners, PATH Concept Home Charleston project manager