Green Building

Making a sustainable home doesn’t just mean going green–it means creating homes with lasting value that contribute to the productive growth and positive health of the communities in which we live. Habitat for Humanity Portland/Metro East has a commitment to green building and continuously looks for ways to make homes affordable to live in and affordable to buy.

Energy Star and Earth Advantage

The Energy Star Program offers solutions for cost effectively increasing home energy efficiency. These solutions reduce energy costs and save money by making homes more affordable, sustainable, and livable for lower-income families while helping the environment. Every Energy Star home is designed to provide its residents with comfort and quality while maintaining our standards for energy efficiency, indoor air quality, environmental responsibility and resource efficiency. For more information, please visit energystar.gov.

Earth Advantage is another step of green building. All Earth Advantage homes are Energy Star efficient, and are designed to improve energy efficiency by 15 percent over a conventionally built home. The incorporation of products such as energy-efficient windows, appliances, mechanical systems and light fixtures can add up to lower energy usage and greater comfort year round. For more information about Earth Advantage, please visit earthadvantage.com.

Forestry Stewardship Council Certified Lumber

Habitat is partnering with the Forest Stewardship Council (FSC) and Sustainable Northwest Distribution to provide FSC certified local lumber for our 2011 Women Build home on NE Mallory Street. The lumber for the current build is being acquired locally by Sustainable Northwest Distribution from the Forest Grove Watershed according to sustainable FSC practices.

This pilot project is just the start of what we hope will be a long-term partnership to help Habitat continue to build sustainably while supporting our local economy.

The FSC is a nonprofit organization that sets international and local standards and principles for sustainable forestry management. The FSC has outlined principles and criteria for certification of lumber and forestry management that range from compliance with laws, indigenous peoples’ rights, environmental impact management plans and education for all ages. More information about the FSC and their programs can be found on their website at fscus.org.

Platinum LEED Certified Homes

LEED (Leadership in Energy and Environmental Design) is a Green Building Rating System developed by the U.S. Green Building Council. LEED promotes design and construction practices that increase building performance, while reducing the negative impacts of building on the environment.

In March 2009, Habitat for Humanity Portland/Metro East completed the first LEED-certified Habitat homes in Oregon proving that going green can be affordable. Located on NE Webster, the two Platinum-rated homes include environmentally and energy efficient uses of the location, housing design and construction. Habitat partnered with the Cascadia Green Building Council, Walsh Construction Co., and Bank of America to make the project possible.

This demonstration project was an opportunity to utilize many non-traditional products and systems that Habitat wished to learn about. A large amount of the materials and labor for this project were donated, which allowed the homes to be affordable for low-income families. The families will purchase the homes at cost and pay a 0% interest mortgage. While building green can be  more expensive, the long-term benefits of lower-energy cost help make these additional up front costs worthwhile. These role-model buildings were dedicated to the Clark and Alemayoh families and are one of 20 national finalists of the EnergyValue Housing Award from  the “NAHB Research Center,” a subsidiary of the National Association of Home Builders.

Site Features

Landscaping, Paving and Fences
Drought tolerant and native plant species were chosen to conserve water during the dry summer and provide a mix of plants appropriate for this area. An existing driveway on the site was broken up and saved for paving the patio terraces. The wooden decks of both homes uses boards reclaimed from a nearby demolished project. The fences are constructed from wood approved by the Forest Stewardship Council.

Rainwater harvesting and Drip Irrigation
The metal roofs provide a clean surface for collecting rainwater for storage in underground cisterns. Two 1150 gallon plastic tanks are buried in each courtyard to store water for site irrigation. The tanks are sized to provide enough water to get through the dry season without using potable water to irrigate. Drip irrigation runs throughout the yard and is controlled by a timer.

North-South Orientation
By placing the homes and primary living spaces on an east-west axis, the houses maximize southern exposure for passive solar heating in the winter and even daylighting throughout the year. In addition, shallow floorplates and careful window alignments take advantage of the north-south prevailing winds for cross-ventilation during the hot summer months.

Design

Connection between inside the home and outside
The front entries of the homes each face the street and provide a porch to welcome guests or watch the world go by. Even with two units on a small 50×80 lot, the design provides each unit with private outdoor space. The living areas open out on this space, which are screened by fences, thick walls, or windows placed high on the adjacent house.

Bar and Frame
The layout and construction type of these homes respond to the common challenges of dense urban living on a small site. The thick, low walls of the “bar” contains service functions such as kitchens, baths, and utility rooms, and helps screen each home from its neighbors. The “frame” of each house is a larger, open volume that holds the living spaces. The structure of the frame provides a clear span so that the spaces can be left open or divided into smaller rooms with non-load-bearing walls.

Sheltering/Collecting Roofs
The roof forms were designed to optimize the collection of both energy and water. The large home is sheltered by a single plane, lifted towards the sky and oriented south to maximize its solar exposure for anticipated on-site energy generation. Deep overhangs provide shade in the summer but allow sun in the winter when it is needed most. Designed as a pair, the roofs were also designed to collect and channel water to rainwater storage tanks located in the central courtyard.

Construction Features

Faswall Masonry Units
In an effort to explore new and different local green technologies, these homes are among the first in the Pacific Northwest to use a Faswall construction system. The wall form blocks are manufactured in 24″ long modular units and weigh less than 30 lbs. The blocks are stacked on top of one another without mortar. The interlocking end design keeps the wall forms in place. Rebar is set both horizontally and vertically within the stacked forms prior to filling the cores with concrete. Faswall has built-in thermal, acoustical and fire protection. Given their superior sound resistance, these insulated concrete forms are used to create the low, thick walls that form the “bar” that wraps each home.

Concrete floors and slab foundation
The concrete contains fly ash which is produced in the combustion of coal and is the non-combustible mineral portion of coal. Buried within the floors is a hydronic heating system made of a flexible plastic hosing that carries hot water heated by the oversized water tank throughout the ground floor levels of each home.

Advanced Framing
While wood frame construction is common in most residential projects of this scale, these homes are unique in their use of advanced framing methods for a large portion of the building assembly. The studs are space at 24″ on center, as opposed to the typical 16″, to reduce the amount of wood used to create the walls of the structure. In addition, the windows along the north and south faces have been placed to fall on the stud layout, thus reducing the need for additional framing around the window openings.

Advanced Wall Assembly
The exterior framed walls improve the energy performance of the homes by additional insulation, air tight sealing, and reduced thermal bridging. While most homes use an open batt insulation in their wall cavity with an insulation value of R19, these walls use a spray-in fiberglass insulation donated by Owens Corning that creates a tighter seal and provides an insulation value of R22. In addition, the entire structure is wrapped on the outside in a layer of 1″ rigid Foamular insulation, which eliminates “thermal bridging” (heat and cold being conducted through the studs) and increases our overall wall assembly to an exceptionally efficient insulation value of R26. This unique assembly helps achieve an energy performance that is estimated to be 40% better than what is currently required by code.

FSC Certified Wood
Wood is one of our most commonly used construction materials, and yet there is often little attention paid to where it is from and how it was harvested. In these homes we use only wood that has been certified by the Forest Stewardship Council, verifying that all of our lumber comes from environmentally and socially sustainable sources that responsibly manage this invaluable resource.