Martha Rose Construction, 5-Star Single Family New Construction

Marpac Construction LLC
Vital Stats
Location: Licton Springs, Seattle
Star Level: 5-Star
Checklist: Single Family New Construction
Verifier: Tom Balderston
Site and Water185
Energy Efficiency 183
Indoor Air Quality 158
Material Efficiency 128
Total Score 786

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Martha Rose Construction, LLC, a longtime leader in advanced green building, has recently completed two new homes in Seattle that take the next step in green building-one that may have big implications for the new home market.

These homes pioneer the concept of Net Zero Ready in a mid-price range that is affordable for large numbers of buyers. A Net Zero Home is one that generates as much renewable energy on site as it uses over the course of a year. The homebuyer receives long-term savings in the form of decreased or even negative electricity bills along with a 30% personal tax credit, and additionally, the Net Zero Ready home provides ready-to-go solar panels as a buyer option. The panels may be purchased or leased, but in either case the monthly cost of the home is designed to be the same or less.

The project, named City Cabins at Indian Wall, improves a challenging lot across from the Indian Heritage School in Seattle's Licton Springs Neighborhood. The attached duplex homes scored 786 points-a number that resides among the top scoring 5-Star projects. They achieve very low energy use with a combination of super insulation, air sealing, and very efficient heating, lighting and appliances. Key energy features that go beyond the average include:

  • Simple design shapes with a large south facing shed roof for solar capacity
  • Slab-on grade floors with full insulation and thermal breaks
  • 2x6 Walls with 1" exterior foam and R23 BIBs Insulation
  • Roof trusses with R60 FG batt insulation, installed to "Grade 1" standards
  • Triple pane windows with a .22 U-value
  • Very tight construction (1.0 ACH50) with Heat Recovery Ventilation for continuous fresh air
  • Infrared electric heating panels which provide instant heat and better zoning than other systems.
  • Heat pump water heater
  • ENERGY STAR appliances, including a condensing clothes dryer.
  • 100% LED lighting
  • Pre-wired for a 6 to 10 KW photovoltaic system

In addition to advanced energy performance, the homes demonstrate some of the most extensive reuse of materials we have seen yet, all of which came from deconstructing the run-down duplex that had been on the site. Few builders use recycled lumber, but this one came up with 50% of the framing lumber and 100% of the flooring, stair risers and trim by using demolition for reuse strategies.

There are many other features that take the homes well past the minimums needed to reach the 5-Star level. The exterior areas are 100% pervious, with a green roof on the second floor deck and rain water cisterns part of the front yard design. The front entry features cork siding panels, which are very sustainable and provide a warm feel. The interiors are comfortable, with carefully selected nontoxic finishes and paints used.

One of the two homes had a large PV system installed soon after it sold. The home's design is graceful and stands as an asset to the neighborhood, with the solar roof sloping down from the taller townhomes to the north toward the open space to the south. With this project, Martha Rose and other Seattle builders are firing the starting pistol on a new race-the one to make Net Zero Homes affordable for all!

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Use pervious surfaces to reduce rainwater runoff