Habitat for Humanity of Orange County designs and builds its homes to be comfortable, durable, healthy, and sustainable. This adds up to a quality home that has taken into account the importance of the homeowner family and the environment.
Since 2008, HHOC has built 48 green-certified homes, and 12 more are in progress. HHOC was the first Habitat affiliate in the Triangle area to build green-certified homes, and the Phoenix Place development in Chapel Hill is its first completely green-certified neighborhood. HHOC homes are a popular stop on the Triangle's annual Green Home Tour each May.
HHOC decides which components and features it wants to use in order to meet the requirements of the National Green Building Standard and the desired level of green certification. There are mandatory requirements in each category, with additional options that allow flexibility in the design. Each new home built by HHOC is green certified by a third-party inspector, Southern Energy Management.
Tom Finn, Construction Project Manager for HHOC and chairman of the Green Home Builders of the Triangle, explains how HHOC's practices earn green certification for our homes.
Site Design and Development
In order to achieve the goal of building green communities, planning must start at the very first step: the design process. The Phoenix Place community is accessible to mass transit and promotes pedestrian activity through the inclusion of sidewalks and a community playground. During the construction process, HHOC installs fencing to protect vegetation from being disturbed. When construction is complete, the natural landscape is restored and enhanced using native and regionally appropriate grass, trees, and vegetation.
A key component of green building is the reduction of waste through the efficient use of resources. HHOC follows Advanced Energy's SystemVision framing guidelines, which seek to reduce the amount of material required for construction. Pre-formed roof trusses and floor i-joists are manufactured by local businesses, and nearly all waste is sent to a certified recycling center.
HHOC homes are small, with an average size of 1,150 square feet, and designed with durable materials to reduce the need for maintenance. For example, 18-inch roof overhangs help to shed water away from the house and exteriors are clad in vinyl siding.
Energy Efficiency and Indoor Air Quality
Just as important as the efficient use of resources during construction is the efficient use of energy after completion. HHOC installs only CFL or LED light bulbs and Energy Star appliances, windows, and ceiling fans.
One way that HHOC helps to make its homes healthy and comfortable is by having a balanced ventilation system that keeps the temperature consistent throughout the home. Transfer grills above interior doors help to facilitate air flow between rooms. The system is minimally affected by the exterior temperature due to several factors, such as control of air infiltration, proper insulation installation, and sealed HVAC ducts. A closed crawl space helps to reduce moisture infiltration and heating and cooling demands.
The home and its duct work are tested to verify proper tightness and ventilation, and are designed to allow constant fresh air flow from the outside.
To encourage a healthy indoor environment, HHOC chooses to use cabinets, flooring, insulation, and paints that are low in or free of volatile organic compounds (VOCs) which can introduce gases into the air.
All toilets are dual flush, and shower heads and faucets are low flow. Additionally, all faucets that run hot water are within 30 feet of the water heater to reduce the loss of heat during transit. Traditionally, sprinklers are installed as an isolated plumbing system, but HHOC's sprinklers use the home's existing plumbing, reducing the need for additional materials.
The final piece of the puzzle for building and sustaining a green community is the education of new homeowners. Before purchase, future HHOC homeowners are required to complete 325 hours of sweat equity. While helping to construct their own homes and those of their neighbors, they learn about the green features and their purposes. Around the time of purchase, they receive a comprehensive homeowner's manual, which includes appliance users' manuals, a diagram of the home's safety valves and controls, a maintenance checklist, and information on local recycling and the benefits of using CFL and LED light bulbs. Tom reviews this manual with the new homeowners and answers any questions they have. The new homeowners also walk through their home with Tyler Momsen-Hudson, HHOC's Construction Director, for a hands-on explanation of how the home's features—including the green features—function.
"Most HHOC homeowners live in their homes for a lifetime," says Tom. "Building healthy and sustainable homes with solid construction means those homes will last for the homeowner's lifetime and beyond. For HHOC and for me, that's personally rewarding."
In collaboration with the ICC (International Code Council), the National Association of Home Builders developed the National Green Building Standard, which established green practices and provides criteria for rating green practices. An HHOC home is considered green certified after Southern Energy Management, an independent third party, inspects and assesses the home.
Energy Star certified new homes must meet strict energy efficiency guidelines set by the US Environmental Protection Agency and the US Department of Energy. Southern Energy Management evaluates each HHOC home to ensure it is at least 15% more energy efficient than homes built to the 2009 International Energy Conservation Code (IECC), and that it features additional measures that deliver a total energy efficiency improvement of up to 30% compared to typical new homes.
Advanced Energy SystemVision provides training and technical support to aid affordable housing builders and developers in the design, construction, and certification of energy efficient affordable homes. Once completed, each home in the program receives two guarantees: the average monthly cost to heat and cool the home will be less than $30, and the center of each room will not differ from the thermostat setting by more than three degrees—the comfort guarantee.