When it comes to energy efficiency, most older homes have a lot of room for improvement. Even newer homes designed to be very energy efficient may still perform poorly. Diagnostic evaluations and inspections by a specially trained building professional can help uncover errors and fix potential problems that drive up utility bills, make your home uncomfortable, or affect indoor air quality.
Making improvements that go beyond energy efficiency code requirements are within the reach of every homeowner undertaking a remodeling project. You may even choose to take your home energy improvements to the ultimate level, by transforming your home into a zero-energy home that generates as much energy as it uses.
Upgrading your home's energy performance may sound daunting, but there are programs and professionals ready to help you. If you're a California homeowner, be sure to check out Energy Upgrade California and GreenPoint Rated. These programs provide comprehensive green home performance services that address energy efficiency, water savings, resource conservation and indoor air quality.
Whole house inspection and diagnostic testing
Before undertaking a major remodeling project, consider having your home tested for air leaks, effectiveness of the heating and cooling systems, and combustion safety. Home Energy Rating System (HERS) technicians are certified to conduct these building inspection and diagnostic services. Find HERS professionals through your architect or contractor or at www.EnergyUpgradeCA.org.
Inspection and diagnostic evaluations should include the following three measures:
- Test the heating and cooling duct system's air delivery in cubic feet per minute (cfm). The results should be within 10% of the air flow that the system was designed to deliver. The technician will also pressurize the ducts and verify that leakage is under 15%. If leakage is greater than 15%, have a heating and cooling system contractor make the necessary improvements to the duct system and test again.
- Perform a blower door test to estimate the interior natural air changes per hour (NACH) for the whole house. This test will give you an indication of how much air is leaking out of your home through cracks and gaps around windows, doors and other openings. The NACH should be close to or less than 0.35; if it isn't, make any necessary improvements and have it tested again. Find out about sealing air leaks in our know-how feature on Insulation and Weatherization.
- Perform a carbon monoxide test to check that all gas appliances are operating safely. Additionally, perform a combustion safety test to ensure carbon monoxide is not backdrafting into the home from an open-combustion fireplace, water heater or furnace. Find out more in our know-how feature on Carbon Monoxide and Combustion Safety.
Exceeding Title 24 energy efficiency requirements
California's Building Energy Efficiency Standards (known as Title 24) set energy efficiency requirements that apply when an existing home is remodeled or a new home or addition is built. Title 24 merely establishes minimum standards required by law. If your goal is to have a green home, you'll want to go beyond those basic requirements.
Consider working with an architect, builder or other building professional who is well versed in energy efficiency to identify opportunities where exceeding Title 24 will be cost effective or provide other significant benefits, such as improved comfort, indoor air quality or durability.
Near zero energy homes
In a near zero energy home, the amount of energy produced is approximately equal to the amount of energy needed on an annual basis. This is achieved through a combination of passive solar and energy-efficient design, renewable energy generation, and your household's energy conservation practices.
To achieve a near zero energy home, start by looking for ways to minimize your household's energy consumption as much as possible. Then supply the remaining demand for energy through renewable systems such as solar hot water and photovoltaic (PV) systems.
These are the basic strategies for getting to near zero energy:
- Utilize passive design strategies to make the most of the sun's warmth in the winter while keeping out heat in the summer. These strategies include designing the home with good south-facing orientation, using thermal mass such as tile or stone floors to store solar heat, and designing rooms for natural cross-ventilation. Passive solar design is explained in our Major Remodeling and Additions Overview.
- Insulate well and choose high performance windows.
- Select high efficiency appliances.
- Make sure heating and cooling systems and water heaters are well designed and tested to ensure they are operating properly for performance.
- Install control and monitoring systems that help you reduce energy consumption and give you feedback about where and when you are using energy. Check with your local utility company for smart metering options.
- Use renewable energy sources like PV and solar hot water to produce the remainder of energy needed.
Check out all our Energy Efficiency Overview for more ways to get your home to near zero energy.
Get GreenPoint Rated
Remodeling can be a daunting process, especially if you want to make sure it's done in an environmentally friendly way. The good news is, there's help available. GreenPoint Rated helps homeowners and builders navigate the process of green remodeling.
When you hire an independent GreenPoint Rater, he or she will work with you to create a customized list of green construction practices that will be used in your remodeling project. This process addresses the full spectrum of green remodeling, including energy efficiency, resource conservation, indoor air quality, water conservation and community benefits. Your GreenPoint Rater will coordinate with your construction team to verify that the green improvements are being done correctly, and will complete the documentation to apply for your home's GreenPoint Rated label.
Recognized as the mark of quality for green homes, the GreenPoint Rated label serves as an independent verification that a home was built or remodeled according to proven environmental standards. A GreenPoint Rated home can save you money on utilities, maintenance and repairs. The GreenPoint Rated label can even improve your property value when you sell your home.
For details and to find a GreenPoint Rater in your area, go to www.GreenPointRated.com.
More tips on home energy performance
- Find resources, rebates and more. Energy Upgrade California serves as a one-stop shop for home improvement projects that lower energy use, conserve water and natural resources, and make your home healthier and more comfortable. Visit their website for help with planning upgrade projects, locating participating contractors, and finding rebates and incentives.
- Get your Title 24 compliance documentation done right. When you remodel a home or build a new home or addition in California, you need to submit Title 24 energy code compliance documentation along with your building permit application. Title 24 analysts who complete this documentation are not required to be certified, so the quality of the analysis is variable. The California Association of Building Energy Consultants has created Certified Energy Plans Examiner (CEPE) and Certified Energy Analyst (CEA) certifications to differentiate Title 24 analysts who have demonstrated knowledge and experience with the code. To make sure your Title 24 compliance documents are accurately prepared, use (or ask your architect or general contractor to use) a CEPE or CEA.