Energy Conservation in Historic Buildings

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Plannin​g & Development Services
301 E. Huron Street
Ann Arbor, MI

Historic Preservation Coordinator
Jill Thacher
734.794.6265 x 42608 

Administrative Assistant to the HDC
Mia Gale
734.794.6265 x 42665

​​​​Making Your Historic House Green 


Is your house wasting energy? While there’s ​no denying that some historic buildings are big energy users, they can be easily retrofitted to reduce the amount of energy they use and some may not use as much energy as you think! Because energy and heat were not as readily available when early homes were constructed, they were built to be as efficient as possible for the time. For example, deep overhangs provide shade in the summer, keeping the house cooler, yet allow sunlight and warmth into the house in the winter. Masonry walls are slow to heat up in the summer months, providing a cooler house. In the winter the walls absorb sun during the day, radiating the heat back into the house.

The National Park Service recently updated their guidelines for sustainably rehabilitating historic properties, which includes information about improving energy efficiency. This information can be found online at:

General information about historic buildings, sustainability, and energy efficiency:

Energy Audits

The way to determine exactly how your house performing is to conduct an energy audit. This will show where there are air leaks, how efficiently your furnace and hot water heater are working, and where energy use occurs in your house.​

Get started on making your historic house green:​

​Once you have the energy audit results you can create a plan to improve energy efficiency. Start with the easiest and least costly, perhaps even doing some of the minor items yourself. Weigh carefully whether expensive changes will have the energy and cost savings you expect. Improvements that require changes to the historic features of your house—the things that make it unique—should always be last resorts. 

​HVAC​, Water Heater & Boiler​

How old is your furnace or boiler? Do you regularly change your furnace filter? If you have a steam or hot water system has it been regularly cleaned, drained, and maintained? Are the lines or radiators clogged? Are the radiators blocked by furniture or covers? Do the radiators have multiple layers of paint? All of these maintenance issues can contribute to an inefficient heating and cooling system, raising your heating costs and not providing the desired heat. Do you have a programmable thermostat installed? Installing this small item can reduce your heating and cooling bills by allowing you to program when the temperature raises and lowers based on when you aren’t home. How about your hot water tank? Do you drain it regularly to remove sediment that causes inefficient heating? Can you lower the water temperature so less cold water is needed for mixing?​

​Helpful links that explain more of these ideas:

Insulation Strategies​

Did your energy audit show that your house is airtight? Most heat loss occurs through the roof and around windows and doors that are not tight fitting. Additional air infiltration may occur around exhaust vents, through an open, non-existent, or ill-fitting chimney damper, and possibly through gaps in the sill plate, or around the roof and eaves. Air infiltration between conditioned and uncondition​​​ed spaces like an unheated attic can also lead to heat loss. Adding weather stripping to doors and windows will stop the drafts from coming through gaps between and below window sashes and under doors. Temporary, self-adhesive foam strips or more permanent types are available. It is important to eliminate air and moisture infiltration before installing insulation. Insulation will not work if it is wet, and does not necessarily stop all air flow. Adding insulation to the attic will stop the most heat loss because heat rises. Insulating crawl spaces and basement areas is also important. Some wall cavities may also benefit from adding insulation. It is VERY important to ensure you have a proper vapor barrier when installing any insulation to keep the insulation from getting wet and causing wood to rot. Consult a professional with experience in insulating historic buildings if you need assistance.​

Here are some websites with additional guidance on insulation:

Energy-Saving Windows


Popular advertising encourages homeowners to replace old, drafty, energy wasting windows with the latest and greatest thermally efficient window product. Generally replacement windows are inappropriate for historic houses. Original windows are often one of the most important characteristics of historic buildings, and with proper weatherstripping and storm windows, they can be just as thermally efficient as new thermopane windows. Before you send your original, old-growth lumber windows to the landfill consider taking the following steps:​

  • Install weatherstripping and caulking to ensure windows are tightfitting
  • Install​ storm windows
  • Ensure windows are in good repair - no cracked glass, intact glazing putty

Gather more information about energy-saving windows:

Alternative Energy​

Do you dream of generating your own hot water or electricity—perhaps creating enough to sell power back to the utility company? Some alternative energy sources and technologies may be appropriate for installation in the historic district. For example, new solar panels that look like roof shingles might be appropriate for installation on your asphalt shingle roof. Or you may have a roof that slopes toward the rear of your property where a more traditional solar panel may be installed.

Always be sure to get the approval of the City of Ann Arbor Historic District Commission before ordering any products or starting your project! 

Here are some links to types of products currently available:​

The information presented in these pages is just a sampling of the information available through the internet, libraries, governments and your contractor or architect. 
As with any project it is best to get different opinions and costs to determine which is best for your historic property. Additional energy savings might not be house alterations at all—think about your landscaping, do you have deciduous trees that shade in the summer and allow sunshine in the winter? Do you have landscaping that​​​​​​’s water thirsty or grass that can tolerate low water conditions? How about your appliances, do they continually consume electricity even when they are off? It is important to maintain the integrity of the historic districts, but with some creative thinking it is possible to have the ultimate in sustainability—a re-used historic building that provides energy efficiency and comfort for today’s occupants.