Energy Efficiency at Home Part 3: Windows, Insulation and Leaks

by Karie Fay

In part one of our energy efficiency series, we looked at ways to reduce your heating and air conditioning costs. Part two focused on methods to reduce resource consumption with your electricity, water and appliance usage. In this final installment, we take a look at your home’s “shell” or “envelope,” as well as materials that can help boost your home’s energy efficiency. Think of your building envelope as the outer layer that stands between you and the environment – the windows, walls, roof and floor.

Windows and Doors

Many of the steps to increase your window and door efficiency take little money or expertise, but some measures do require more of an investment. Always research large investments. When buying new windows or doors, take your time and shop around. Also, if you choose to hire a contractor for any of the work, make sure to get an estimate and look into the contractor’s reputation. Careful planning, getting plenty of information and taking your time generally help any job turn out better.

• Close your doors completely whenever you run your heat or air conditioning.
  

• Replace non-working doorknobs, poor latches and faulty striker plates. Repair anything that prevents your door from closing and sealing properly.

• Install weatherstripping around your door frame. This prevents air from leaking around the door when it’s completely closed. With age and use, weatherstripping may deteriorate.
  

• Attach door sweeps to every entry door and storm door. Made from rubber or a variety of metals, sweeps prevent air leakage when the door is closed.
  

• Hang storm doors if possible to help insulate your entry door.

• Replace old, poorly fitting doors with newer, more energy-efficient doors. Wood doors in particular are fairly inefficient, transferring temperature differences readily. Insulated steel or fiberglass doors tend to be more efficient. A storm door helps insulate your wood door if you prefer to keep the wood.
  

• Build an overhang or install awnings above your doors and windows. Not only will it block much of the hot summer sun, but it also helps break the wind and shelter the openings from rain, which can lead to mildew and rot.

• Check each window in your home to ensure it closes properly and completely. Do the window locks pull the sashes together tightly?

• Look for mildew and rot surrounding the window. Inspect for broken or missing locks, cranks or other window elements. Clean, repair or replace as necessary.
  

• Weatherstrip windows to reduce airflow around the moving parts.

• Stand back from each window and door and look closely: Can you see daylight around the window or door? For smaller gaps, run a bead of caulk down the length to fill and seal the void. Expanding foam insulation works well for larger areas as it fills, seals and insulates. Use a special window-and-door formula that expands less than regular types. Follow the product instructions and trim any overflow to eliminate protruding foam.

• Repair or replace broken or cracked glass panes on older windows. Apply putty to the seams between the framing and glass panes as appropriate.

• Replace old, single-pane windows with newer, energy-efficient double-paned windows as your budget allows. While the cost can easily add up, you will actually recoup the investment over time.
  

• When purchasing windows, doors or skylights, look for ENERGY STAR® rated products. Other features to note with windows are a low-e (emissivity) coating, inert gas filling between the panes, insulated sashes, and spectrally selective coatings. A U-value (a measure of resistance to heat transfer) rating of 0.30 or less and a Solar Heat Gain Coefficient (SHGC) rating of the same or less also translate to high energy efficiency. (Note: this is in contrast to the R-value of insulated products, where the higher the R-value – or measure of heat transfer – the better.)

• Install storm windows to boost the energy efficiency of any window, especially older ones.
  

• Consider investing in window film. Specially designed window films will block ultraviolet (UV) light transmission and insulate the glass. You can also find films that increase your home security, making windows shatter-resistant.
  

Home Insulation

Chances are, if your home was built before 1980, it isn’t insulated to today’s energy efficiency standards. Only about 20 percent of such homes are, reveals the Department of Energy. However, insulation’s value goes beyond simply keeping you warm in the winter. In the summer, it keeps the heat out as well. It also helps muffle sound from the outdoors. It also pays for itself over time.

How do I Know if I Have Enough Insulation?

A professional energy audit will use special tools to determine exactly where air leaks and heat loss occurs. You can hire a company to perform one for you, or you might even find a local utility or governmental agency that offers one free of charge or at low cost.

You can also measure the existing insulation if you have access to it. Find the depth or thickness of the insulation, multiply it by the R-value it offers, and you have the total R-value present. Compare your insulation total to ENERGY STAR’s recommended levels of insulation or use the Department of Energy’s R-value Recommendations calculator.

What Insulation Should I Choose?

What works best for you and your home may not be what works best for your neighbor. When selecting an insulation product, you need to factor in where you are installing it, how much of the product it takes to provide the R-value you desire, whether you can install it yourself or need a professional, and any other special features.

The most common insulation forms for the DIYer are rigid foam insulation – basically a sheet of foam that is 4 feet wide and 8 feet long – and fiberglass batts or rolls (which are simply cut to length and either stapled in place through the paper facing or friction-fit between framing). Spray foam in a can is an option for smaller areas, and in larger areas you can hire professionals for spray foam installation. Blown-in insulation in different forms is another option, but generally requires professional installation as well. For more information on insulation types, advantages and R-values, consult the Department of Energy’s information on types of insulation.

Energy-Efficient Measures in Other Areas of the Home

So far we’ve looked at windows, doors and insulation in the walls, floors and attic, but there are a few other areas that may need your attention.

• Install foam or rubber gaskets around light switches and wall outlets located on an exterior wall. Inexpensive and easy to DIY, they will block a significant source of heat and air loss.
  

• Find any opening in your wall or floor, such as around cable and phone lines, and seal around it. Expanding foam or even fiberglass shoved inside the hole will block air while allowing you to remove the line or cord when desired.
  

• Weatherstrip and insulate your attic hatch or door. To insulate it, generally all you need to do is attach a sheet of foam insulation on the attic-side of the door and allow it to overlap the opening so it seals against the frame when closed.
  

• Fill foundation cracks and openings with caulk.
  

• Check kitchen and bathroom vent dampers, along with laundry vents and other openings, to ensure they close tightly. Repair as necessary.
  

• Install a chimney block to eliminate heat loss through your fireplace if you don’t use it often. Make sure the damper closes tightly.
  

• Weatherstrip your garage door and insulate the door as well. Reflective insulation or rigid foam board work best.
  

• Landscape your property. The careful placement of deciduous trees and shrubbery can help block sunlight and insulate your home’s walls.
  

• Winterize and weatherproof your home annually.
  

As you follow the energy efficiency tips in our series, you’re sure to notice a difference. Lower bills, better air quality, and more comfortable temperatures – the advantages of making your home energy efficient far outweigh the drawbacks in time and hassle.