The goal of the Sensible House project was to build a home that is affordable, attractive, comfortable, functional, healthy, and environmentally friendly without compromise. We wanted to create an environmentally-friendly home in a way that most everyone would want, if only they knew it was available and had the opportunity to experience it.

From the contractor’s point of view, this home was a unique opportunity to build an environmentally friendly home which offered all the comforts, benefits, and amenities of a traditional home, with added green features that, we hoped, would contribute to bringing green building to a new level. The project provided me an opportunity to demonstrate many more green components in a single project then I’d ever done in my 14 years of specializing in green building. It involved trying, for the first time, many materials and processes that were new to me, as well as incorporating some that I already knew. It was both one of the most challenging and rewarding projects that I’ve been involved with.

The extent of green building methods successfully integrated into this home could never have been accomplished without a very strong team. The architect, Ted Granger, and I had both worked together and separately on numerous green homes over the years. As a general contractor I’d developed an extensive network of suppliers and subcontractors who were knowledgeable, or at least sympathetic, to green building. Bob, the owner, had done an extraordinary amount of research for the project and had hands-on involvement with its construction. He and his wife Kim spent a great deal of time and effort in thinking about the details of  how to really make this house work for their lives.

From the beginning, the goal was to push our limits on green building practices and products. We elected to deconstruct the existing house instead of remodeling to most effectively reach our energy and healthy-house goals affordably. We salvaged for reuse virtually all materials prior to construction. Many of the materials were re-used in this home; other materials were salvaged for resale. The remaining materials were sorted for recycling. Very little material was sent to the landfill.

The new 1,800 SF main unit, accompanied by a 650 SF accessory dwelling unit (ADU), was designed with “not so big house” principles tweaked into what we call “just the right size” house. Care was taken in the design of the house, to build only rooms the owners would use daily, and making those rooms a functional size and no bigger. We also used design to make spaces “feel good” to enhance the owners wellness by creating sunny spaces, gathering places, and places that connect the indoors and the outdoors.

Since completing construction, when I visit Bob and Kim, the homeowners, they talk about how well this house works for them. They describe the beautiful morning light coming in through their windows… How the heat wasn’t needed until well into the cold season… How quiet the inside of the house is, separated from street noise with its super insulated walls and triple glazed windows… How they’ve met so many neighbors by being out on their front porch and working in the yard... And most of all, how this house feels like it really has soul.

Energy Efficiency

This home has earned both an Energy Star and the platinum level for Engineered for Life certifications.  The house is rated at 90.6 by the HERS standard (Home Energy Rater).  The house is projected to have reduced its carbon emissions by 10,287 pounds per year compared to the average home of its size due to energy efficiency. Its annual heating bill is projected to be $174. (These figures are taken from computer calculations done for the Engineer for Life Program.)

The house features a very energy efficient shell which includes:

• 9 in. thick double framed 2x4 walls insulated with cellulose to R-33.
• Double walls were done with advanced system framing with a 2 in. air gap between them.
• 12 in. R-48 Structural Insulated Panels roof system
• R-43 floors
• Triple glazed U.20 fiberglass windows
• Final Blower door test showing .14 ACH at natural pressure

Blower door test in progress.

The heating system is a hydronic coil system that includes:

• Vacuum tube solar water collector
• Heat recovery ventilator
• Design that optimizes passive solar collection
• 3 KW PV installation

Water Efficiency

The Sensible House is projected to use 115,340 gallons of water per year less then the average 4 person household in Seattle (the average Seattle household uses 100 gallons per person per day). This was accomplished by:

• A rainwater collection system with a 7000 gallon cistern
• Drought resistant landscaping with no turf grass and a drip irrigation system supplied by the cistern
• Toilets that are filled by rainwater from the cistern
• Low flow faucets and high efficiency fixtures
• 3/8 in. inside dimension PEX supply lines used in the house to reduce water waste when hot water is turned on.

Green Materials

EcoStone pavers used in driveway

The house made use of numerous resource efficient materials including:

• Trex decking & railings
• Fly ash in concrete
• Pin foundation footings for stairs & landing
• Salvaged materials for:
  Flooring
  Framing
  Trim & stair treads
  Brick walls
  Door & light fixtures
• FSC wood for:
  Flooring
  Interior trim
  Framing lumber
  Cabinets

Home profile
Owners	Bob Scheulen and Kim Wells
Builder	Jon Alexander, Sunshine Construction
Architect	Ted Granger
Pin Foundation	Used for back steps and landings
Native Planting	Mostly native, but not exclusively
Light Tube	One in ADU
Skylight	One over ADU kitchen
Solar Shading	Eaves designed to maximize passive solar on south side. They are at a 45 degree angle from the tops of the windows
Waterproof details	Rain plane between siding and #15 felt; plane is ventilated at top and bottom and created with ½” strips of plywood. (A better - less expensive & easier - way of doing this is to create the rain plane with a roll-out Enka drain matt.) Windows & exterior doors have built in sill pans with back stop; sill pans drain into the drain plane. Concrete foundation has 6 mil plastic under the footings to prevent water going up through the foundation through a capillary affect; a sealed fiberglass matt under the slab; footing drains around the perimeter; outside of footings and stem walls coated with two coats of Thorough Seal, with a Delta drain then attached to them to prevent hydrostatic pressure between soil & foundation wall. Please Note: This house was built with a basement in a worse case soil environment for water problems (built into clay hard-pan layer that went halfway up the foundation). Three months after the foundation was completed Seattle had a record 5 in. in 24 hour rainfall during which not a drop leaked into the basement.
Efficient Framing	Walls double wall framed 2x4, with 2 in. between, to make a 9 in. thick wall and insulated with blown-in cellouse to R-33. Walls are advance system framing with double top plates. Most of the inner walls (which are considered non-baring) are framed with salvaged lumber. Outer walls make use of FSC and finger jointed lumber. Roof is framed with 12 in., R-48, Structural Insulated Panels (SIPs). Floor joist are framed with I joists. The house was sealed very tightly & the final blower door test measured it at .14 ACH at normal pressure.
Solar Water	20 vacuum tube solar water heater is used to pre-heat water for domestic hot water and heating.
PV	3 KW of panels are installed on the roof.
Over all Energy	With its super efficient shell, efficient appliances & lighting, passive solar design, Solar water heater & PV, this house is very close to being a net zero energy house
Green Roof	None on this house. But more information is on the Green Roof page.
Rainwater Collection	This house has a cast in place concrete 7000 gallon rainwater cistern. The top of the cistern is colored & stamped concrete with functions as a very nice patio in the sun on the south side of the house.  It captures all the water from the house’s downspouts. The water is used to water the landscaping & fill the toilets. This project is the first on in the City of Seattle to get permission to use rainwater for toilets.
Grey water plumbing	Not on this project. I’ve done this on another job & I’ve found that making use of rainwater is easier & makes more sense.
Durable Products	Enhanced durability comes from using long lasting materials, such as 40-year roofing, fiber-cement siding (Hardy Plank), fiberglass windows, quartz-composite countertops, Trex decking & railings, and by not using carpeting or vinyl flooring. Additionally, durability was enhanced by providing large roof overhangs and metal clawed exterior trim, by careful attention to flashing details; and from adding a rain shield system for the siding.
Environmental Products	Salvaged materials: See above listing FSC Products: See above listing Materials that are recycled-content: Compost & soil amendments; 43% fly ash in footing & stem wall concrete pours; about 20% fly ash in slabs; Finger jointed studs used in framing; Cellulose used for insulation; Sheet rock had recycled paper & gypsum content; rebar had recycled metal content; and OSB in SIPs panels has recycled fiber content CDL Waste Management: Recycling rate for the project was 85.7% by weight. Full-line jobsite recycling was done through on-site source separation. Materials recycled included sheet rock, wood, metals, cardboard, concrete, and landscape debris. Numerous steps were taken to reduce waste that included: Pre-existing house was de-constructed by the ReStore and most all the materials were salvaged for reuse (the list of these items is 2 pages long) or recycled Numerous salvaged materials were used as listed above SIP roof structure which uses less lumber then a stick framed roof Non or low toxic products used: No materials used inside the house that contain urea formaldehyde All flooring is hard surfaces. No carpet or vinyl flooring was used. Low toxic materials were used for paints, clear finishes, hardwood floor finishes, glues and caulks. The house was thoroughly vented out after the application of each interior finish All ducting is sealed with a low toxic mastic
Whole house fan or ventilation strategies	For the main section of the house the fresh air is brought in from the outside (controlled by a timer), pre-heated by the HRV, and then distributed throughout the house through the heating duct system. As the air is circulated, a portion of it is filtered by a HEPA filter. For the ADU, air is vented through the bathroom fan, as controlled by a 24 hour timer. Make-up air is brought in through a vent in the roof with a barometric damper & ducked and released behind the refrigerator. Here the fresh air is preheated by the refrigerator coils. The fresh air helps oil the refrigerator coils as well, making the refrigerator run more efficiently. The garage is carefully air sealed from the rest of the house and has a fan on a timer that will come on when the garage door is used.
More information: Photo gallery Green Home Case Study, from the Built Green™ program and the Seattle Department of Planning and Development (pdf) sensiblehouse.org