We built a new home for a couple who are concerned about chemical sensitivity, so in addition to the home being passive solar, ENERGY STAR and energy efficient, it is also non-toxic, using "green" building materials and techniques. "Green" construction means buildings are environmentally responsible and provide healthy places to live.  Here's the Passive Solar Home plan we built:

South Elevation	East Elevation
First Floor Plan	Second Floor Plan

Our homes are designed and built for energy efficiency.

First we build the foundation with a fully sealed crawl space. This means no vents are added to the foundation wall.
The interior space is insulated with Thermax Insulated Sheathing (R-9.7) by Dow, then plastic sheeting is placed on the ground to prevent water coming up through the earth - keeping the crawl space dry. Due to chemical sensitivity, glues commonly used to attach the insulation could not be used. Insulation was tightly attached to the concrete block with screws. Edges of the sheathing were sealed with a "caulk" type product - M-1 Structural Sealant by ChemLink. This product contains no solvents nor VOC's (Volatile Organic Compounds).
	Plastic sheeting seals out moisture. Adding a dehumidifier creates a conditioned space (even though not heated and cooled) that can be used for storage. Photo taken at another home being built in Greentree Community.

	Foundation is weatherproofed.
Innovative Framing Techniques: Walls built flat on the ground and then raised up. This keeps walls straight and even as well as making it easier to add the extra Styrofoam R-3 Residential Foam Sheathing Insulation by Dow.
	Insulation is then sealed around edges and caulk applied to all possible joints on exterior walls as well as between floors and walls. Again, M-1 Structural Sealant by ChemLink is used for caulk. Then Tyvek HomeWrap by Dupont covers the entire wall.
	Flooring: Avoiding toxic chemicals, means no treated products could be used in the home. AdvanTech flooring is an alternative to treated plywood. It is built in layers like OSB, but has a 50-year warranty and withholds water so it won't swell like OSB. The floor joists are nailed then screwed to AdvanTech floor to eliminate the need for any glue.

Windows: Low E argon filled EnergyStar Pella Proline windows are used. On the outside of the home, after the window is installed, the Tyvek HomeWrap sheeting is pushed back into place securely around the window and then Tite-Seal™ self-adhesive waterproof flashing covers the edges of the window to seal the joint and prevent water or moisture from entering the home.
Great Stuff Pro Windows and Doors by Dow Chemical is applied around windows and Great Stuff Pro Gaps and Cracks is used between studs, in corners, etc. They offer a more successful and tight insulating sealant than standard fibreglass insulation. Also once off-gassing occurs it leaves a 100% inert product after 24 hours, which makes it a much greener product and less chemically sensitive than fiberglass insulation. This is all finalized before sheetrock is installed. Photos taken at another home being built in Greentree Community.

Insulation: Corner 2x4 is placed away from exterior wall to allow for blown-in cellulose insulation to be added. This provides extra R-value to home and eliminates gaps as insulation is tight against the 2x4's, for much greater energy efficiency. It fills all spaces around outlets, in corners and along interior walls. Wood is R-1 per inch, blown-in insulation is R-3.5/inch and then Styrofoam sheathing is an additional R-3. Due to the excellent sealing of the blown-in insulation which expands after it is installed, the wall "acts like" it is R-22.
Left photo shows exterior corner of home. Right photo shows wall with gap between 2x4 and Styrofoam sheathing to allow room for blown in insulation to fill all the spaces.
	Left: We insulate behind the tub prior to the sheetrock being installed with rock wool covered by water resistant sheetrock. This insulates and provides an air barrier, while preventing moisture building up on the inside.
	Left and below: Rockwool used in between walls and floors as a sound barrier.

Insulation (continued)
	Blown-in cellulose insulation is non-toxic and made from primarily recycled material. It includes boric acid, which is fire retardant and deters insects
A roller then smoothes the insulation making it even with the walls.
Extra insulation is vacuumed up and returned to the main unit to be reused - ensuring minimal waste of product.	Cellulose makes a very neat and tight seal between the 2x4's and around receptacles.

Heating Ventilating and Air Conditioning (HVAC): The HVAC system is designed and built to save energy. It also provides a comfortable living environment (without hot and cold spots in some rooms). Up to 33% of heat can be lost through duct leakage alone in an average home, so our ducts, pipes and vents are carefully sealed to meet ENERGY STAR® requirements. Most electric companies offer a discount on your utility bill for an ENERGY STAR®home. Our Duct Blaster Test shows performance of 5% or less of total loss in the home.
	Pipes are covered with R6 Insulation, and insulation joints are tightly sealed using Nashua 556 tape by Tyco Adhesives. We have found that this works better than standard duct tape since that does not hold up well in very cold or hot conditions. Mastic paint (duct sealant) is applied completely surrounding the collar and all connecting joints to eliminate any air leakage.

HVAC Continued: Each section of pipe is then taped again with Nashua 556 tape to make a sturdy, and sealed unit.
All vents in the floor and ceiling are sealed with Mastic Paint.

HVAC Continued: When installed each section of pipe is carefully attached to the return air handler to eliminate any gaps where air could leak out.
	Dampers are installed in each duct run to regulate airflow to each room for comfort throughout the house.
The Duct Blaster and Blower Door Tests simulates the air loss in the home as if a 20 mph wind were blowing on the house. First all doors and windows are tightly closed. The Blower Door Test Unit is installed on one exterior door. The fan on the Blower Door unit sucks air out of the house, depressurizing it. Pressure always tries to equalize itself so air from the outside will rush in through any available cracks in the house shell - ceiling, around doors, windows, foundation, floor, plumbing pipes, receptacle holes, etc. The fan on the Blower Door Unit actually measures how much air is coming back into the house and the results reflect the amount of air loss and therefore the size of the holes in the walls. Too tight a house? One concern might be that the house is too tightly sealed and therefore not healthy. Building Science techniques demonstrate the amount of air required for healthy living. Since we can regulate where the fresh air comes in the house (through safe vents directly to the outdoors), the quality of the air is much healthier than in many homes where the "fresh" air seeping into the house could be coming from a moldy basement or from a garage with carbon monoxide fumes or chemicals. An Energy Recovery Ventilation (ERV) system may be installed to exchange the air in the house. The heat/energy in the house is exhausted into the fresh air stream, and new air is pulled into the home. This improves home owner comfort and energy efficiency. Photos of Finished Home   Light from the back door provides a pleasant view down the hallway. These long views give an airy, spacious feel to the home.   Kitchen with door & window to solarium. Connecting views with this glimpse of another room draws you in to want to explore further. Choice of key light fixtures and fans enhance the design. Green Building Materials: Kitchen cabinets were sealed with a non-toxic and odorless lacquer rather than traditional stain to eliminate off-gassing. AFM Safecoat grout sealer from Shelter Ecology and a non-toxic ceramic tile adhesive were used in the kitchen and bathrooms.

The hearth for the woodstove is sealed with Mexeseal water-based sealer, an AFM Safecoat Product, available from Shelter Ecology. The stove doesn't need to be large to heat the home since the building envelope is so well insulated.
The utility room includes a large laundry closet with bi-fold doors. There's plenty of storage and room to hang clothes. Solid tile floors were used in all 3 bathrooms and the laundry room.			Cozy window seat nook in the master bedroom for quiet sitting and reflection. Seat provides storage too!
		No Space is wasted! Shelving and storage space built into interior walls. This shows shelves in the return air duct frame in the master bedroom. Photo taken at another home being built in Greentree Community.

Family room looking through to sunny living room with passive solar gain.
			Light and sunny views throughout the home. Natural light is crucial to livability of space in a smaller home. Each room has light coming from two directions, with minimizing the windows on the west.
Green Building Materials: The home has all solid flooring for better indoor air quality. The pine wood floors are a local product, so have less embodied energy and help support the local economy. They were first screwed down rather than glued to eliminate using traditional floor glues. Then they were stained with Bona Eon 70 low VOC water based finishing system. This product from Bonakemi provided a beautiful non-toxic satin finish. Since stair treads do need to be bonded well for safety and to eliminate squeaks, we used Enerbond from Dow Chemical. It's a polyurethane foam which is 100% inert once dried. Off-gassing is complete within 48 hours. The Genesis line of no-VOC paint by Duron was used for all interior walls and trim. Interior doors were stained with a AFM Safecoat Poly sealer from Shelter Ecology. Metal railings were selected for the entryways to eliminate the need to use treated lumber.   Green Building Materials: Hardiplank siding is a wood by-product mixed with concrete. It takes paint better than wood and needs less maintenance. With a 50-year warranty it provides beauty and durability. Light paint colors were selected for heat reflectivity. For the roof, we used 40-year shingles combined with Titanium UDL underlayment. This product is stronger and lighter than tar paper and with the lighter colored shingles provides reflectivity for a cooler roof. Exterior lights are Halogen for directional lighting and compact fluorescent for area lighting. And finally for indoor air quality, there was a no-smoking policy inside the home at all times during construction. Results? This home met the goal of non toxicity for chemically sensitive homeowner. No airing out is needed because there is no off-gassing. Home passed Energy Star® standards of energy efficiency.