Weatherize Your Home!

Keeping the Heat In (or out in summer)

About half of the energy we use at home goes into heating and cooling.  We need to be comfortable in our homes, and heating needs to be affordable.  Weatherization, air-sealing and insulation upgrades can substantially reduce home heat loss, benefit your health and comfort, shrink your carbon footprint and save you money. Big savings are possible today with incentives and rebates from your utility and a small investment goes a long way. Some simple tasks make good do-it-yourself projects for even greater savings.

Recommended Actions:

  1. Sign up for a free energy audit here. Massachusetts “public” utilities provide a free energy audit to residents every two years. An energy auditor will help you find the places where air leaks into or out of your home and where you need more insulation. Through your electric bill, you have already been contributing to a fund that will pay for 75% of all cost of insulation you need. (Many people even qualify for free weatherization – everyone who receives or is eligible for fuel assistance. You can check if you qualify here.
  2. Air-seal your home. Your energy auditor will do this as part of the audit, but if you are a DIY kind of person, you can easily take care of this yourself. Air leaks account for 1/4 up to 1/2 of home heat loss and are a primary cause of ice dams. Warm air rises and escapes, drawing cold drafts in from below. Every home needs a continuous “air barrier” to prevent this airflow. Air sealing at the gaps will stop the drafts. Simple and inexpensive sealants and gaskets can eliminate uncomfortable and expensive drafts. All homes are unique; older homes will benefit the most from air-sealing.
  3. Upgrade your insulation. Your home’s thermal barrier resists heat flow through ceilings, walls, and floors. Heat flows in every direction at once from warm to cold. Insulation upgrades are an opportunity to save big. R-Value is the ability of insulation to resist heat flow. To compare materials, look at R-value PER INCH. Good insulators have high R values. Recommended R values for the ceiling, wall, and basement of buildings are based on location and climate.
  4. “Draft proof” your home. Doors and windows typically have little insulation value and air leaks around them create drafts. Draft-proofing with simple weather-stripping and sealants will improve comfort and save energy. This is an inexpensive and simple do-it-yourself project.

Financial Considerations

Air leaks in a home waste energy which increases utility costs. Taking steps toward weatherizing your home can make a significant difference in your utility bills.

Typical Costs

Costs depend on what you are doing. One of the preliminary steps in weatherizing your home is an energy audit, which is provided for free, see the link above. The Department of Energy provides examples of weatherizing DIY saving projects. Also, Energy Star provides detailed tips and steps depending on what type of project you’d want to take on to get started. They even help you consider what projects your home needs.

Environmental Benefits

By wasting less energy, we decrease environmental pollutants and greenhouse gas emissions.  


Q: What causes ice dams and how do I prevent them?  A:  Most ice dams are caused by flaws in a home’s air barrier. Escaping indoor air finds its way to the underside of the roof sheathing, raising the temperature, so snow on the roof melts over the attic and refreezes on the eaves. If the ice dam is big, water can leak into the house when it melts again. To prevent ice dams, eliminate air leaks in the attic floor and at cathedral ceilings. Insulate and seal air ductwork too. Keeping warm air away from the roof is essential. Insulate the attic including the perimeter and ventilate it properly. Attic insulation must completely cover the top plates of a home’s exterior walls. If you have to replace the roof, you could install a rubberized membrane under the roofing to help further.

Q: Where should I insulate first? What type of insulation should I use?  A: An insulation upgrade in the attic is inexpensive and easy. Begin with the attic but you can cut thermal heat loss wherever you add insulation. In general, cellulose is inexpensive and more effective than fiberglass. It is messy so it is good for attics and walls. Polyurethane foam is very effective but costs more. Foam boards and spray foams provide continuous insulation and air barrier improvement. Foam must be covered with gypsum board for fire safety. Talk about your options with a contractor. MassSave has a list of them.

Q: What about my windows and doors?   A: Windows are a weak link in your building envelope but very expensive to replace and have a long payback period for your investment. Make sure existing windows close tight and keep them in good repair for best results. Use curtains to keep heat in at night. Upgrade to double-pane low-e glass with insulated frames if you have single-pane windows now. Low-e glass is one that has been coated with a substance that reduces “emissivity”, keeping warm air in during the winter and warm air out during the summer. This could save 1/3 of your seasonal heating cost. New or replacement storm windows (and storm doors) can double the efficiency of existing openings. Results are comparable to those of replacement windows at a fraction of the cost. A removable interior window sash can be an inexpensive option too. You can build those yourself for under $15 per window, if you are willing to spend a little time on it. If existing single-pane windows are in good shape consider buying good quality storm windows with a low-e coating. Low-e storm windows work about as well as double-pane low-e replacement windows at a much lower cost.

Q: What is the MassSAVE Heat Loan Program?  A: The Mass Save Heat Loan program offers 0% loans to help you make qualified energy efficiency home improvements (subject to loan approval). In addition, through the Expanded HEAT Loan program, customers may be eligible for a grant to remove asbestos and knob & tube wiring (subject to funding availability).


  1. Green Building Advisor:
  2. Department of Energy: Weatherize 
  3. Insulation basics
  4. Ice dam basics
  5. Mass Save rebates and incentives