Older and historic homes present special challenges for homeowners who wish to make their homes more energy-efficient. Common recommendations for making homes more energy-efficient may be inappropriate for older homes. In some cases, the materials and techniques that can be helpful in improving the energy efficiency of newer homes can cause damage to older homes, which can compromise home values. It is possible to make older homes more energy-efficient, but it is important to make changes with consideration to preserving the features of the home.
Schedule an Energy Audit
An energy audit can help homeowners spot air leaks that may be negatively impacting heating and cooling efficiency and energy usage. Energy audits are often offered by local utility companies and professional energy audit companies. During an energy audit, auditors will usually review the last twelve months of energy bills to assess current energy efficiency and sometimes use an infrared temperature sensor to identify temperature alterations around suspected areas of leakage.
Air leaks are often spotted in areas such as:
•   Attic hatches
•   Crawl spaces
•   Electrical outlets
•   Chimney Flues
•   Door and window frames
•   Garage doors
•   Dryer Vents
•   Window AC units
•   Utility line entrances
Utilize Existing Passive Energy Conserving Features
Most older homes include features that help keep the home heated or cooled without using energy. For example, many homes in the Northeast were constructed in a position that allows cold winds to pass over the roof slope and travel up the mountain so that homes are kept warmer in the winter. Balconies, shutters, porches, shade trees, and high ceilings are features that were added to homes to keep the homes naturally cooler.
Improve Home Insulation
Many older homes are not properly insulated, which can severely impact the home’s energy efficiency. However, blown-in or spray foam insulation can cause damage to older homes. Old wiring in the walls can also create a fire hazard when insulation is added. Before insulating walls in a historic home, it is important to consult with an expert and have the home thoroughly evaluated. If insulation is installed, the process should also be completed by professionals to ensure safety.
Replace Windows and Doors
Air leaks around windows and doors are responsible for about 10 to 15 percent of a home’s energy loss. Replacing windows and doors can help to improve energy efficiency, but may alter the look and feel of a historic home. There are restoration companies in some areas that can help homeowners improve energy efficiency while keeping the look and feel of the home by restoring older doors and windows. Weatherizing windows and doors can also help to increase efficiency without changing the look of the home.
Update Home Heating, Cooling, and Ventilation Systems
As with many of the other mentioned elements above, there is not a one-size-fits-all strategy for HVAC systems. It’s important though to have an air sealing and insulation strategy in place before moving on to purchase more expensive HVAC systems. With better air sealing and insulation, you’ll be able to purchase smaller heating and cooling equipment, saving money. Heat recovery ventilation or energy recovery ventilation might also be an option. Retrofits are generally more challenging for installing the necessary ductwork for HRV installation but you can submit plans and a quote request to see if it is possible to provide fresh ventilation and save energy for the building.  For historic homes, it is often necessary to check with local historic preservation offices before making changes.
For more information about preserving energy in older and historic homes, please visit the following sources:
http://energy.gov/sites/prod/files/energy_savers.pdf
http://epa.gov/region5/sustainable/energyadvice.html?_ga=1.230258719.221143299.1425232656