If your historic New England home is cold in the winter or expensive to heat, you’re not alone.
Attic insulation is one of the most cost effective energy-saving measures for New England homes, yet many in the greater Portland area have inadequate amounts of attic insulation compared to the recommended levels for our climate.
While insulating an attic in general is a fairly straightforward energy-saving solution that will make it easier to warm or cool your home as the weather demands, it can be a tricky project, especially for older and historic houses.
Space
As a first step, you must determine the boundary between living spaces and the outside, and determine how that boundary can be made more effective in terms of energy efficiency. It may take some extra time or the help of a professional to figure that out. Some homes simply don’t have an accessible attic. Cathedral ceilings or eaves can make the job a bit trickier.
If you use your attic for storage, you will need to decide whether you have the space for the necessary insulation. If you can dedicate the space exclusively to insulation, that’s ideal, but you could also reserve one area of the space for storage. This is also an excellent opportunity to pare down on your stuff, an exercise that is getting a lot of attention these days in light of Japanese de-cluttering expert Marie Kondo’s bestseller, “The Life-Changing Magic of Tidying Up.”
If you don’t need a significant amount of attic storage space or if your attic is finished and used as living space, you can still insulate the rafters. In that case, use insulation that is removable and reversible and meets a minimum energy efficiency standard.
Other Considerations
If there’s existing insulation in your attic, it may be able to stay in place, depending on its condition. If any of it looks dirty, that’s a sign that there’s been air movement from below and any air leaks should be sealed before any new insulation is installed.
If your attic has been home to mice or squirrels, or if the insulation has become wet from ice dams or other water damage, it should be removed. If you have vermiculite insulation, some contractors recommend removing it.
If you have soffit vents, baffles should be installed to protect against wind intrusion. And if you have knob-and-tube wiring, check whether it’s live. Insulation contractors won’t install additional attic insulation in that case.
Methods
There are many kinds of state-of-the-art insulation materials used today, but for most Maine attics, cellulose is usually the preferred type. Cellulose’s consistency allows it to settle between door joists and in nooks and crannies missed by any original insulation. In a plus for historic houses, it’s also removable and reversible, allowing access to utilities and for making future alternations.
Insulation is available at home-improvement retailers, but having your attic assessed and insulation installed by a professional is advisable. Thankfully, the energy savings from properly installed insulation can be substantial, so the task usually pays for itself.
For more information, download a free copy of Greater Portland Landmarks’ workbook The Energy Efficient Old House. For additional information visit www.efficiencymaine.com to find a qualified energy partner.