New windows look great, boost the value of your home and increase energy efficiency. Many models are easier to clean. Imagine being able to clean both sides of your windows from inside your house!

If you're thinking about buying new windows, use this handy FAQ as a guide to asking the right questions, comparing costs, and making an informed decision about an important investment in your home.

Q. I live in an old house with drafty windows. Should I replace them, or can I just repair them?

A. If you have time and energy to repair your existing windows, that may be the most cost-effective option. However, there are some instances where windows simply aren't worth repairing:

- The wood is rotting. Unless you have the time and skill to replace the wood and maintain it, consider replacement.

- The double-pane glass is fogged. Condensation between the panes can't be fixed. You have to replace the glass to get rid of the problem. Putting in new glass is expensive; you may want to compare it with the cost of a whole new window.

- You can't find hardware for it.

- Your old windows are a hassle. One drafty window that sticks might be charming, but a house full of them will drive anyone crazy. New windows are easy to open, airtight, and simple to maintain.

Replacing residential windows will run you about $150 to $400 (or more) each, depending on size, glass, window style, and framing materials. If you have them professionally installed, tack on up to $350 labour cost per window.

Q. What are my options when it comes to new windows?

A. You have a number of choices for the glass, the style and the frame of your new windows.

1. Glass
Most new windows are double-pane or triple-pane. Double-pane windows use two sheets of glass with air sealed inside. Opt for windows filled with argon gas, which slows heat transfer and keeps things cooler on hot days. Also look for windows that have low-e (low emissivity) coating, which lets in light while dissipating heat.

2. Style
You have two main choices: casement or double-hung. Casement windows open using a lever or crank, and seal tight for maximum energy efficiency. Double-hung windows are the traditional ones that slide up and down. They're a little less energy efficient, since the sashes have to be loose enough for the window to slide smoothly.

3. Frame materials
Your best choices include vinyl and fiberglass. Avoid plain aluminum frames, which conduct heat, and wood, which requires maintenance and can warp over time.

Q. New windows aren't in my budget. How can I make my existing windows more efficient?

A. To keep your home cool when it's hot out:

- Use white drapes or shades to deflect heat.

- Install awnings over south and west windows, and keep the drapes shut during the day.

- Apply a sun-reflective film to the glass.

To keep things warm in winter:

- Put in storm windows. They'll reduce heat loss by up to 50%.

- Keep drapes open during the day so the sun can help heat your home.

- Install insulating window shades.

- Attach clear plastic film to keep cold air out.

Whether you decide to repair or replace your windows, you'll get the best results if you do your research, and spend some time comparing costs and quotes.