Insulation
Insulation is a critical process for enhancing the energy efficiency of homes, particularly older ones that may lack modern insulation standards. One of the most essential components of this process is insulation, which plays a pivotal role in reducing heat transfer and maintaining a comfortable indoor environment. Older homes can significantly improve their energy efficiency by upgrading or adding insulation to areas such as attics, walls, and crawl spaces. This leads to lower utility costs and a more sustainable living space. Moreover, proper insulation helps protect these historic structures from moisture damage and air leaks, ensuring their longevity and preserving their unique architectural character for generations.
While many properly installed and selected insulation materials are sufficient, the U.S. Department of Interior’s Guidelines on Sustainability for Rehabilitating Historic Buildings makes several suggestions for protecting and preserving as much of the original property as possible. Firstly, reduce air infiltration wherever possible using caulk, weatherstripping, and energy-efficient retrofits. These measures will not only improve your home's heating/cooling efficiency but will do so with minimal damage to the existing structure. It is also vital that you do not attempt to insulate a finished space (i.e., living spaces and finished attics/basements) unless the walls have deteriorated to the point where they need to be replaced. This is because original plaster, trim, beadboard, wallpaper, and other materials may be permanently damaged during removal and installation.
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Ideal for unfinished walls, including foundation walls, floors, and ceilings
Fits between studs, joists, and beams.
Relatively inexpensive.
Easy to DIY
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Ideal for unfinished walls, floors, ceilings, and low-slope roofs.
High insulating value
Must be fire-proofed if used indoors
Must be weather proofed if used outdoors
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Ideal for unfinished attic floors, but may not be recommended for use in wall cavities for historic buildings.
Good for unused, finished areas
Requires specialized equipment
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Ideal for unfinished walls, ceilings, and floors.
Fits between studs, joists, and beams
Helps prevent downward heat flow
Easy to DIY
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Commonly used in wall cavities or unfinished attic floors but is not recommended for use in historic properties.
It is important to note that many historic and older buildings were constructed with a gap between the interior and exterior walls specifically to create a dead space. In these cases, applying insulation may not be advisable because filling these cavities may contribute to rot and accelerate the building's decomposition. Also, avoid wet-spray or other spray-in insulation, which will trap or hide moisture. Instead, allow the dead air space between walls to naturally insulate and focus on adding additional insulation to the attic, basement, crawlspaces, and pipes when possible.
Basements and crawlspace Insulation
Basements, crawlspaces, and areas above unairconditioned garages are also highly important for insulation. Particularly in older homes, installing insulation against the interior basement walls may be inefficient; however, if the basement or crawlspace areas are unoccupied and unconditioned, you can seal them off from the rest of the home by insulating between the floor and subfloor.
Insulating pipes
Wrapping insulation around heating and cooling ducts also prevents the conductive heat loss that occurs due to uninsulated pipes and ducts. It is important to use insulation that is intended for use in these areas and follow the manufacturer’s guidelines.
Wall Insulation
Contrary to how many newer homes are built today, the National Parks Service does not recommend insulating the walls of historic and old homes. This is because, in addition to possibly damaging the walls during installation, blown-in and foam insulation can trap moisture inside the walls and accelerate rot and mold growth. However, if a wall is already in severe disrepair, it is considered acceptable to do a complete replacement with a properly installed moisture barrier.
