Historical buildings were built when neither advancements in technology nor construction technology was in abundant supply. Early designers made the most of building materials and design options to construct buildings with a powerful combination of harnessed natural resources and innovative design that worked together to maximize energy efficiency.
Everything from exterior paint colors, locations of balconies, numbers and placement of windows, to physical placement of buildings on lots was carefully considered to maximize heating, lighting, and ventilation in traditional construction.
The results are astounding, and studies have shown that properly restored and maintained 18th-, 19th, and early 20th century buildings can be just as energy efficient as new construction, and in many cases even more efficient.
The historical wood windows in your building contribute to that energy efficiency, and, contrary to urban legends, new replacement windows are not more energy efficient than historical wood windows. Typically, studies that conclude such a finding have compared new replacement windows with historical windows that have not been maintained or restored, are decaying, and have no complementary energy retrofits, such as weather-stripping and storm windows.
Studies on energy efficiency also usually fail to consider “embodied energy”. Embodied energy represents the energy it took to manufacture a product. They say the greenest building is the one already built. This is true when you consider the embodied energy – an existing energy investment that will never be able to be recaptured once you destroy the product it’s embodied in.
Historical wood windows have an embodied energy value that includes all the energy from harvesting and milling the wood to transporting and manufacturing the windows to installing them in your historical building. Preserving existing windows conserves that embodied energy and eliminates the need of additional energy to manufacture replacement windows. When you take all energy into consideration for defining the energy efficiency of windows, historical wood windows are far more energy efficient than replacement windows.
Tips For Improving Energy Efficiency
Here are some tips for improving the energy efficiency in your historic home.
- Have a maintenance appraisal performed. When not properly maintained, there are many ways a historic home’s energy efficiency suffers – such as air leaks into and out of the home. A maintenance appraisal performed by a qualified contractor will locate any source of air leakage and provide you with a plan-of-attack to remedy the problem without damaging the historic aspects of your home.
- Schedule an energy audit. This could really be tied for the #1 spot; both the maintenance appraisal and an energy audit are absolutely essential things that need to be done BEFORE you implement any energy improvement measures. The energy audit will evaulate your home’s current energy performance and identify any deficiencies in both the envelope of your home and/or mechanical systems.
- Implement these findings. Hire a qualified contractor to eliminate any air infilitration, repair windows and perform the other maintenance affecting your home’s energy efficiency. Hire a qualified energy contractor to replace any mechancial systems found to be deterimental to your home’s energy efficiecny. Make sure both of these contractors have a proven track record of working with historic buildings in a way that does not damage the architecture and its features.
- Change your habits. Install timeers or motion detectors on lights, attach self-closing mechanisms on doors that might otherwise hang open, install fans and raise your thermostat temperature, use LEDs in your lights and turn off “vampire” devices that use electricity in standby mode or that use electricity in standby mode or whenever that are plugged into an outlet.
- Install insulation. Ther is a lot of misinformation regarding the best ways to insulate your house, and some of them can even damage your home. Have the historic contractor and energy consultant you hire work together to devise an insulation plan specifcially tailored to your home, so you won’t compromise its architectural integrity.
Historically Sensitive Storm Windows
A Product Recommendation from Chuck
When storm windows first came into use to promote energy efficiency, they were installed on the outside of the house. Not only did this take away from the architectural integrity of the house by impeding the view of major architectural features in windows, they also often created moisture on the outside of the window.
Fortunately for historic homeowners today, we have better options now. And the option we recommend here at Historic Restorations are the interior storm windows by Allied Window.
Allied offers an “invisible” storm window installed on the inside of the window. One of the major benefits of this storm window option is that it has a low profile that doesn’t limit visibility of a window’s historical architectural features. Made from aluminum they can also be painted any color – send them a sample of the color of your trim and they’ll match it for a seamless integration into your window’s look. They also have a good seal with an aluminum u-channel across the top, magnetic strips that the aluminum frame attaches too, and a rubber or brush seal that sits on the sill.
They do offer an exterior option with the same features of the interior. Some people think this would be the better option, that an exterior storm window would help protect the wood in their window. I don’t recommend this option – wood needs to breathe moisture and if there is a storm window installed on the exterior moisture will be trapped in the wood and promote rot.
We’ve had a good long-term experience with Allied. We’ve tried other companies, much to our dismay, and Allied is the one that has provided a consistent service and product performance over time.
You can learn more about the products that Allied Windows offers by visiting their website at alliedwindows.com.
Increasing energy efficiency in historic buildings is always a hot topic. Here are our Top Six Tips for improving the energy efficiency in historic buildings:
Have a Maintenance Appraisal Performed to Increase the Energy Efficiency in Historic Buildings
When not properly maintained, there are many ways energy efficiency in historic buildings suffers – one of which are air leaks into and out of the home. A maintenance appraisal performed by a qualified contractor will locate any source of air leakage and provide you with a plan-of-attack to remedy the leakage without damaging the historic aspects of your home.
Schedule an Energy Audit to Increase the Energy Efficiency in Historic Buildings
This could really be tie for the #1 spot – both the maintenance appraisal and an energy audit are absolutely essential things that need to be done BEFORE you implement any energy-improvement measures. The energy audit will evaluate current energy efficiency in your historic building and identify any deficiencies in both the envelope of your home and/or the mechanical systems.
Implement a Maintenance Plan to Increase the Energy Efficiency in Historic Buildings
After you have these two critical reports in your hand, set to work implementing them. Hire a qualified contractor to eliminate any air infiltration, repair windows, and perform the other maintenance affecting your home’s energy efficiency. Hire a qualified energy contractor to replace any mechanical systems they’ve found to be detrimental to your home’s energy efficiency. Make sure both of these contractors have a proven track record of working with historic buildings in a way that does not damage the architecture and its features. Maintenance is one of the most critical aspects of improving the energy efficiency of historic buildings.
Change Your Habits to Increase the Energy Efficiency in Historic Buildings
This can be the toughest one to do, but if we truly want to increase the energy efficiency of historic buildings then our habits have to change. Some of these changes can be easy – install timers or motion detectors on lights, attach self-closing mechanisms on doors that might otherwise hag open, install fans and raise the thermostat temperature, use CFLs in your lights, unplug “vampire” devices that use electricity in standby mode or whenever they are plugged into an outlet (most chargers, DVD players, etc.).
Install Insulation to Increase the Energy Efficiency in Historic Buildings
Installing insulation in strategic places can be a cost-effective solution to energy loss – but make sure you are not installing the insulation in ineffective places and ways. There is a lot of misinformation floating around out there of the best ways to insulate your house, and some of them can even permanently damage your home. Have the historic contractor and energy consultant you hire work together to devise an insulation plan specifically tailored to increase the energy efficiency of your historic building that won’t compromise its architectural integrity.
Use Shading Devices to Increase the Energy Efficiency in Historic Buildings
There are several ways you can make use of shading devices in ways that are historically compatible to increase the energy efficiency of historic buildings. Many historical homes made use of exterior awnings and if there is evidence your home may have originally had awnings you can consider installing them again. Some homes may still have their awnings on them – if yours does, maintain it well for maximum benefit. Trees, bushes, and other foliage are another good way to shade your home during the summer to increase energy efficiency if you have the space. As is hanging drapes and curtains on any windows receiving direct sunlight and keeping them closed during the sunlight hours.
The Technical Preservation Service at the National Park Service offers Preservation Brief #3: Improving Energy Efficiency in Historic Buildings that provides an in-depth look at this topic. You can read the brief online at: nps.gov/tps/how-to-preserve/briefs/3-improve-energy-efficiency.htm