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Case Studies  > Concrete Helps Achieve First 5-Star Built Green® Rating
“Sensible House” is Smart, Affordable, & Neighborly
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patio over cistern
Completed patio on top of cistern tank with recycled brick planter and dry-stack recycled concrete retaining wall.  Photo courtesy of The Sensible House.org.

“The Sensible House”, was the first Seattle house to win five stars, the highest possible ranking, in the Built Green® program sponsored by the Master Builders of King and Snohomish Counties. To meet green goals economically, the owners chose to deconstruct an existing 1948 home on the site instead of remodeling it. The new 1850 square foot home sits on the old building footprint, but is actually two homes, having a 600 square foot accessory dwelling unit (ADU) on the first floor; a basement which includes a garage, shop, and storage space; a second floor; and attic on the third floor. Concrete helped the project achieve points around:

  • recycling/re-use,
  • water conservation,
  • stormwater management,
  • recycled content, and
  • durability

Rainwater harvest. A 7000 gallon concrete cistern doubles as a rainwater storage tank and patio in this home with attached apartment in north Seattle. All of the rain water that falls on the roof flows into this poured-in-place concrete tank, which measures 10’ x 16’ x 6.5’ deep. Its lid does double duty as a sunny patio bordered with a recycled brick planter. Rainwater is pumped from the tank for toilet flushing and used to irrigate the drought-tolerant landscape. This saves an estimated 15,000 gallons of water per year when compared to a similar home that doesn’t collect rain water.

Stormwater management. To preserve the infiltration of water throughout the site, solid concrete was used only in the driveway between the sidewalk and the street and in the concrete cistern whose top is an impervious patio. Water runoff from the patio is taken through a recycled brick planter that edges the patio. EcoStone pervious pavers, set in a twelve-inch bed of gravel, pave the rest of the driveway and allow rainwater to infiltrate while resisting weeds.

Recycling. The builder used a cement mix with 43% fly ash, a coal combustion by-product in the concrete foundation walls and footings, and 20% fly ash in the floor mix. Fly ash helps make concrete stronger and recycles a waste material into a useful product. Recycled concrete from the old home creates pathways and retaining walls throughout the landscape.

Durability. Fiber-cement siding, a mix of cement, sand, and cellulose fiber, provides an appearance similar to that of traditional wood siding; yet will not rot, buckle, or warp, and can hold paint well. The siding is actually set out away from the inner sheathing in what is called a “rain screen” sheathing system. The gap created by this system allows any wind-driven rain that gets between the siding and the sheathing to drain away through vents at the bottom of the wall.

Other green features of the “Sensible House” can be reviewed at http://www.sensiblehouse.org/and at http://www.ci.seattle.wa.us/dpd/stellent/groups/pan/
@pan/@sustainableblding/documents/web_informational/dpds_007231.pdf
. The extensive project documentation provides the general public with in-depth practical information about green building in order to encourage its use.

Project Team:

Owners: Bob Scheulen and Kim Wells
Architect: Ted Granger
Builder: Sunshine Construction, Jon Alexander