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Weatherization Guide for Older & Historic Buildings

There is a good reason for the current intense focus on existing and historic residential energy efficiency retrofits -- about 75% of all buildings that will exist by 2030, the target year for many greenhouse gas reduction policies, exist now. Efficient energy performance from existing buildings is critical to the success of greenhouse gas reduction goals.

A wealth of good technical information and resources available online. The National Trust's Weatherization Guide for Older & Historic Buildings is a good place to start. It offers homeowners a one-stop resource with the latest information about how to make their home more energy efficient and comfortable - without spending a lot of money or compromising the historic character of their home.

Building Performance

The profession of Building Science is playing a larger role in existing building energy retrofits.  The Building Performance contractor tests the building for thermal and infiltration anomalies, identifies deficiencies and recommends corrective action. After the corrections have been performed, a second test is administered to measure the improvements and to isolate any defective or insufficient work. The second test performs as both a quality control and as the means to determine any third party certification of the building, if desired.

Why Third Party Certification is Desirable

Third party certification will become higher profile in the future. City ordinances in California are being considered now to require energy performance information at the sale of a building or home. A third party certification would satisfy these requirements and signal to potential buyers that the home performs efficiently, an additional selling point. There are several third party certifications currently available in California. Some are:

Home Energy Rating System (HERS): This system is in the process of being revised to reflect the goals of achieving net zero energy performance.  A net zero energy use home would have a rating of zero. Scores closer to zero are better.

HERS industry organizations:
Residential Energy Services Network (RESNET)
California Building Performance Contractor’s Association (CBPCA)
California Association of Building Energy Consultants (CABEC)

GreenPoint Rated for Existing HomesBuild It Green is a non-profit membership organization whose mission is to promote healthy, energy- and resource-efficient building practices in California.They work with mainstream stakeholders in the housing industry to accelerate the adoption of green building practices. Build It Green has also created its own rating system for California, called GreenPoint Rated. They train their own inspectors, and maintain separate rating systems for new and existing construction. Historic and existing homes need a minimum of 50 points on the Existing Home scale in order to earn GreenPoint Rated certification.

Some cities, such as San Francisco, encourage historic homeowners to energy retrofit by adding points for the amount of character defining features retained, and discourage the teardown of historic homes by increasing the threshold of points required for certification if a historic building is demolished.

Build It Green has an innovative approach towards energy upgrading existing homes as well; homes that plan to remodel parts, such as a kitchen or bathroom, can plug into their “Elements” plan, which gives partial point credit that qualifies for both stand-alone certification and towards a complete upgrade of the home later.

Home Energy Performance with ENERGY STAR offers whole-house solutions to high energy bills and homes with comfort problems. The program is managed by a local sponsor that recruits home improvement contractors who are qualified to perform comprehensive home assessments. The assessment includes the heating and cooling systems, windows, insulation, flow of air into and out of the house, as well as a safety check of gas appliances. Based on this assessment, participating contractors offer solutions to fix comfort problems and address high energy bills.

LEED: The U.S. Green Building Council has several LEED (Leadership in Energy and Environmental Design) products, two of which are applicable towards historic buildings. LEED for Homes is a rating system that promotes the design and construction of high-performance green homes. It is not relevant for existing homes. LEED for Existing Buildings: Operations and Maintenance is focused more on the commercial market and is concerned with fine tuning the maintenance and mechanical operations of a building, but could be applied towards a historic building. LEED for New Construction and Major Renovation can be applicable for major renovations of historic buildings.  USGBC and ASID (American Society of Interior Designers) together offer a home renovation guideline called ReGreen, which is not a rating system.

LEED has typically not been a product that is preservation-usable, however efforts are ongoing to work with USGBC to make their products more inclusive. More recently LEED for Neighborhood Development has included preservation-friendly credits, and the most recent update for LEED 2012 includes some credit for whole Building Reuse as part of their Materials and Resources category.

Efforts continue to be ongoing to work with USGBC to make their products more inclusive. USGBC itself has been in dialogue with several agencies, and regional chapters of USGBC have been expressing interest in including existing building retrofits, which represent the majority of energy consumption in the US.


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The ILLUSTRATED GUIDELINES ON SUSTAINABILITY FOR REHABILITATING HISTORIC BUILDINGS offer specific guidance on how to make historic buildings more sustainable in a manner that will preserve their historic character and that will meet The Secretary of the Interior’s Standards for Rehabilitation. Most historic buildings are inherently sustainable and that this should be used to advantage in any proposal to upgrade them.The written guidance is illustrated with examples of appropriate or “recommended” treatments and some that are “not recommended” or could negatively impact the building’s historic character.

Graphic: NEW!Weatherizing and Improving the Energy Efficiency of Historic Buildings This National Park Service website provides energy efficient tips for improving a historic building’s envelope. Weatherization means implementing cost-effective measures to make a building’s envelope more energy efficient. Weatherizing a historic building requires undertaking those measures in ways that have minimal impact on the historic building’s design and materials.

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Loan Program will Help Sacramento Energy-Saving Retrofits -A high-powered investment coalition assembled by Richard Branson, the eccentric British billionaire, is offering Sacramento a shot at hundreds of jobs through a $100 million energy-efficiency program. Sacramento is one of two cities chosen by Branson's nonprofit Carbon War Room group for a privately financed effort to retrofit office buildings and other commercial properties. The other city is Miami; the program would total $650 million.

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Energy Upgrade California offers home improvement projects that lower energy use, conserve water and natural resources, makes the environment healthier, and identifies contractors, rebates, and incentives.

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Rehab a Home w/HUD's 203(k): The Federal Housing Administration (FHA), which is part of the Department of Housing and Urban Development (HUD), administers various single family mortgage insurance programs. These programs operate through FHA-approved lending institutions which submit applications to have the property appraised and have the buyer's credit approved. These lenders fund the mortgage loans which the Department insures. HUD does not make direct loans to help people buy homes.

The Section 203(k) program is the Department's primary program for the rehabilitation and repair of single family properties. As such, it is an important tool for community and neighborhood revitalization and for expanding homeownership opportunities. Since these are the primary goals of HUD, the Department believes that Section 203(k) is an important program and we intend to continue to strongly support the program and the lenders that participate in it.

Many lenders have successfully used the Section 203(k) program in partnership with state and local housing agencies and nonprofit organizations to rehabilitate properties. These lenders, along with state and local government agencies, have found ways to combine Section 203(k) with other financial resources, such as HUD's HOME, HOPE, and Community Development Block Grant Programs, to assist borrowers. Several state housing finance agencies have designed programs, specifically for use with Section 203(k) and some lenders have also used the expertise of local housing agencies and nonprofit organizations to help manage the rehabilitation processing.

See also: "A Little Known Loan Program for Fixer Uppers" New York Times, Oct 15, 2010.


Energy upgrades for historic and existing buildings can be expensive!  Policy makers and the private sector effecting reduction of greenhouse gasses are acknowledging this and looking for the means to help finance the upgrades as an incentive to improve as much existing construction as possible. Some mechanisms available in California are:

Municipal Energy Financing: The cost of the energy upgrade of existing homes is tied to the property and funded by the local jurisdiction, which bills the property owner in monthly installments akin to, or even as part of, a property tax. The debt is paid by the property owner who is also benefiting from the added energy efficiency. AB 811 is the legislation in California that enables cities to create this funding. Some jurisdictions already using this authority are Berkeley, Palm Desert, Santa Monica and Sonoma County.

Energy Efficient Mortgages: Energy efficient mortgages allow home buyers and homeowners to refinance their property to add energy efficient upgrades as part of their mortgage transaction. Energy improvements are usually defined using a third party rating or certification and must be cost effective.

Federal Tax Credit: The U.S. government has been encouraging energy efficient investment by offering a 10% tax credit through the end of 2009.The American Recovery and Reinvestment Act (ARRA) has expanded and extended this tax benefit to 30% through 2010.

Utility Rebates: Utilities offer a variety of incentives to reduce energy usage and rebates for qualifying products. These offers vary by utility.

California Energy Commission’s Energy Conservation Assistance Act Loan program: One-percent and three percent loans are available to local jurisdictions. This loan program adds American Reinvestment and Recovery Act (ARRA) - State Energy Program (SEP) funding to California's existing Energy Conservation Assistance Account Program (ECAA), allowing the Energy Commission to provide loans that can help local jurisdictions invest in energy efficiency, save money, reduce greenhouse gas emissions, and build new jobs and industries for their communities.