High-performing homes 2017: Highly energy-efficient in a classic coastal neighborhood

This is just one of a series of high-performing homes highlighted in the spring 2017 issue of GHM Homes. See the rest here.

 Photo: Sandy Agrafiotis

Photo: Sandy Agrafiotis

South Portland, Maine

INSPIRED BY THEIR lovely coastal neighborhood in South Portland, the owners wanted to create a high performing home that matched the classic aesthetic of the surrounding area, rather than the boxy style that is common with many contemporary homes. The home needed to be large enough to accommodate the owners full time and their children who visit them often, along with a two-car garage.

Faced with a small buildable area and 26’ height limitation, the solution was to build a one and a half story home over a sunken garage. The result, a Net Zero Ready, cedar shingleclad beauty, adorned with natural stone and exposed rafters that looks like it belongs here.

The smart 3-bedroom home features 4” of foam under the basement slab, a thick double-stud wall assembly, and an energy recovery ventilator that works in tandem with the tightly sealed exterior envelope.

Why we like it: This home follows the Pretty Good House philosophy. Meeting metrics was not the primary goal, but creating a comfortable, highly energy-efficient home that fits into the neighborhood on this tight site was the guiding star. The home features a 12” double stud wall assembly, triple pane tilt-turn windows, and copious amounts of insulation. While the driveway snow melt system (necessary for the belowgrade garage) is markedly not energy-efficient, the home itself performs impressively.

EFFICIENCY:

Net Zero Ready

BUILDING ENVELOPE:

Slab—4” concrete over 4” of rigid EPS insulation R-20. Foundation Walls—10” poured concrete with 3 1/2” rigid insulation R-22. Walls—Double stud walls with dense packed cellulose R-35. Roof—Flash and batt rafters (spray foam and dense packed cellulose) R-52. Windows—Triple pane American tilt-turn windows. Airtightness—untested

SYSTEMS:

Heating and Cooling—High efficiency natural gas condensing boiler. Ventilation—Venmar ERV

RENEWABLES:

none

SIZE:

3566 sq ft

COST:

$240/ sq ft

PROJECT TEAM

  • DESIGNER: Briburn

  • BUILDER: Rainbow Construction

  • RENEWABLES: none currently

  • ENERGY/PERFORMANCE CONSULTANT: Briburn

 

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This article was reprinted from the spring 2017 issue of Green & Healthy Maine Homes. Subscribe today!