This new house would have been located on a lot in the second phase of Sharingwood, a co-housing development northeast of Woodinville, near Lost Lake, in Snohomish County. The community has approximately 40 acres of mixed woodlands. The development is an air-space condominium, with 18 homes is the first phase, and 12 in the second. Homes are clustered near the center, with the surrounding acreage left as a greenbelt.This will be a totally "green" construction project. The owners are very committed to minimizing the use of building materials and construction practices that may damage the environment and/or may be dangerous to human health, and maximizing the use of durable, energy-efficient, resource-efficient, and healthier materials and design techniques.The first and probably most important conservation design tactic is to design a smaller house. We're aiming for 1,500 square feet for this 3-bedroom home with study.

Draft Specifications

Sitework

• The site slopes at about 25%, which translates to about 18 feet from on the buildable portion of the lot, with the main entrance to the house on the high end. Sitework will include one set of exterior steps, probably stone, with vertical gap in risers for ground cover.
• Septic system alternate: a "subsurface flow constructed wetland". Wastewater flows into an ordinary septic tank and then into a plastic-lined wetlands bed before reaching a smaller than normal drain field disposal area. The small wetlands area consists of two 25 foot trenches each 3 feet wide by 18 inches deep (150 square feet). The trenches are lined with impervious plastic, filled with pea gravel, and covered with mulch. Various species of water-loving vegetation, including bulrush, sedge, and lily, are then planted. (Cost: $2,000-3,000.)
• Retaining walls made with recycled concrete aggregate, fly ash admixture. Trellises would be made by placing masonry nails in a regular grid pattern, and stringing 20 guage copper wire between them.
• As an extention to the house, an outdoor room will be created with walls of a planted hedgerow and roof of open trelliswork covered by a grape arbor.

Basement Floor

• Remilled fir at Master Bedroom & Closet on Junkers clip system, ceramic tile at M. Bath, linoleum at Storage, all over PFG industries EasyFloor system for hydronic floors [Bio-coverstone tiles joined with joint bar, modular plastic interlocking blocks, thermal reflecting foil, (206.463-1267)] on concrete slab on grade with fly ash added to the mix, full insulation, over poly vapor barrier on 6" washed pea gravel. Soil gas venting via ABS pipe to roof.

Main Floor Floors

• 3/4" remilled fir on Junkers clip system at Living Room, natural linoleum on 5/8" strawboard on 1/2" homosote underlayment at Kitchen, Pantry, Bath and Dining, over 2x T&G beadboard fir decking on 3x3 purlins on doubled 2x6 center beam.

Exterior Walls Below Grade (retaining wall at west of lower floor)

• Cement stucco over insulated concrete forms. Fly ash added to the infill concrete mix.

Exterior Walls Above Grade

• Alternate A: Rainscreen wall with advanced framing and airtight drywall approach. (~R-25)
• Above belly band (at window head height): 4x8 rough sawn cedar panels with vertical 1x2 battens 12 inches on center. Below belly band: 6" lap cedar siding from a well-managed source. Sidings as noted above on 1/2" x 3" vertical plywood furring 2'-0" o.c. over building paper on 1 1/2" tongue and groove EPS rigid insulation over 2x6 wood studs 2'-0" o.c. with unfaced R-19 Owens Corning "Miraflex" encapsulated fiberglass insulation, 5/8" LP Fiberbond wall board, gasketed top & bottom and at studs, latex vapor retarder paint.
• Alternate B: Timber frame with insulated panels. (~R-27)
• Typically 4'-0" x 8'-0" non-structural insulated panels consisting of 1/4" rough sawn cedar plywood exterior face with 1x4 battens at joints (copper flashing at horizontal joints), Weather-Bos stain, 7 1/2" EPS foam insulation, 1/4" OSB on interior face. Hung on z-clips on beam at top and bolted with brackets to 4x4 remilled fir posts 4'-0" on center, with blocking top and bottom to leave 2 1/2" raceway for plumbing & electrical runs. Between posts, removable 1/2" fir plywood panels with clear finish, screwed to 1x1blocking on posts. Fasteners and brackets stainless steel.

Interior Walls

• Alternate A: 2x3 wood studs, 16" o.c., 5/8" GWB. Walls between baths and bedrooms and public areas to have sound insulation.
• Alternate B: Same as above, except fir plywood panels with clear finish, screwed to studs instead of GWB. 1x4 remilled fir battens 4'-0" o.c. continue spacing of posts.

Doors & Windows

• Double glazed, argon filled. Operable casements and fixed. Quantum or Northwest Window Works fir windows. Wood from sustainable source.

High Roof

• Terne coated stainless steel standing seam roofing with water collection system, over R-38 rigid insulation on 2x T&G beadboard fir decking on 3x3 purlins on exposed remilled fir and steel rod trusses 8'-0" o.c. Trusses built up from 2x members, none larger than 2x8.

Low Roof

• Planted roof, SupraNature system by Soprema. Planted with low-growing, low-maintenance wildflowers.

Finishes

• Paints: Safecoat by AFM or Best Paints. Clear finishes: O/S system for walls, trusses, trim. AFM Polyureseal BP for floors.

Cabinets

• From Environmental Home Center. Shaker style fir doors, 1/2 of kitchen uppers with glass fronts. Doors made with fir from sustainable source, clear finish. Cases strawboard substrate with white melamine.

Countertops

• Terrazzo with colored recycled glass. (Kevin Spitzer)

Appliances

• Refrigerator: Vestfrost
• Washer/Dryer: Maytag Neptune front loading.
• Dishwasher: Bosch
• Range: Dacor electric, with ribbon elements.
• Range Hood: TBD
• Microwave: TBD 

Fixtures & Fittings

• BioLet composting toilet downstairs, low-flush standard toilet (Kohler EcoLite) main floor.
• Faucets:
• Sinks: 

Mechanical

• Sealed combustion combination heat/hot water boiler, with zones for in-floor radiant hydronic system for lower floor, and in-wall or kickspace hydronic fan/coil units for main floor, perimeter Runtal radiators for Living Room and Guest Bedroom.

Electrical

• Provision for addition of PV panels to roof as the price comes down. Use high CRI T-8 and compact flourescents for most applications.