Q: Years back, we converted part of our attic into a nice guest bedroom for my mother, who visits every June. Now my mother is coming to live with us full time, but that room is uncomfortably cold in the winter, even though we put hot-water baseboard heat in there. What's the best way to insulate the room? We put beautiful wide-plank knotty-pine boards on the slanted ceiling/walls, but without insulation. We don't want to touch those boards, so would it work to insulate the floor of the room instead?

A: Insulating the floor would make the space colder because you would prevent any heat from rising from the room below it. It would also raise your heating bills because the baseboards in the space would have to put out more heat. (Think of the insulation in attic floors. That's designed to keep heat in the house instead of escaping upwards.) You can, however, nicely insulate the walls of this room without disturbing the interior that you love.

A Home Performance with ENERGY STAR certified shell specialist can do the job. ('Shell' is a construction-industry term for a building's skeleton, to which the finished exterior and interior are applied.) He or she can gain access from the roof or the side attics. A tube can be inserted along the slope of the ceiling. Then, insulation is blown-in through the tube. You can find a contractor through www.efficiencyvermont.com/homeperformance. After the insulation is installed, this beautiful room may end up being the most comfortable part of the house.

Q: How would you prevent frozen pipes in mobile homes without using heat tape?

A: Some mobile home park owners in Vermont require heat tape on homes' incoming town water pipes. So, you may not have the option to make this change. But if your home isn't in such a park, you can get good results with a thorough job of insulating the pipes and enclosing them (insulation and all) in an air-tight box that extends from a few inches below ground all the way to the inside of the home. The underbelly of the mobile home should be insulated and air-sealed and the skirting around the mobile home slab should be insulated.

If you find that you still need to supply heat to prevent the pipes from freezing, use a thermostatically-controlled heat cable that is inserted into the water pipe, not a heat tape that wraps around it. And don't use an incandescent light bulb to heat pipes. It's both a fire hazard and an expensive way to add heat to a space.

Q. I'm buying an 18-year-old log home. I love the look of the interior log walls, but I'm concerned because they're not insulated. Do logs insulate well? If not, is it possible to add insulation?

A. Appealing as they are, log walls typically have less than half the insulating value of standard stud frame walls. So, be sure to air-seal (close-up gaps with caulk or expandable foam) your attic floor, foundation and around windows and doors. As for adding insulation, unless you're prepared to build and insulate conventional walls inside those logs that you fell in love with, your best option is to insulate foundation walls with rigid foam board and the attic with blown-in cellulose.

Q. I'm shopping around for replacement siding for my home. Is there a siding product that can help insulate as well?

 A. None of the common siding products used in Vermont help with wall insulation. But if you're hoping to increase your home's energy efficiency, there are a few things you can do to help insulate your walls while the siding is being replaced:

• If your old siding is being removed, you can add foam insulation behind the new siding. This is an excellent way to increase wall insulation. However, with thicker foam insulation panels, the trim around windows and doors will need to be replaced.
  
  
• You can also identify and seal air leaks and add insulation to the wall cavity with dense-packed cellulose. To find out whether this is a good option for your house, contact a certified Home Performance contractor or a qualified cellulose insulator. For a list of professionals in your area, visit the Marketplace.

Q. Does Efficiency Vermont offer rebates on windows, doors or insulation?

 A. Efficiency Vermont offers incentives on certain energy efficiency improvements that are the most cost-effective when it comes to saving electricity. Since the savings from replacing windows and doors is usually small and very site specific, we don't offer rebates on these items. However, the federal government's new Energy Policy Act (EPAct) does offer tax credits for qualifying improvements, including windows, doors and insulation.

If you're looking to save money by reducing heat loss around your home, look at reducing air leakage first. It's typically the greatest single source of heat loss in any house, and reducing it is one of the most cost-effective ways to lower your heating and cooling bill.

For other ways to save energy in your home, contact a certified Home Performance contractor. These professionals can help you identify the best opportunities, while also protecting health and safety and improving the comfort and durability of your home. You can find a list of certified Home Performance contractors in your area at the Marketplace.

Q. How do I prevent icicles from forming on my roof?

 A. Icicles are a sign that you have heat loss. You're smart to want to prevent them. They form when melted snow trickles down and refreezes at the more exposed and colder eave. Ice that builds up on the edge of the roof and holds back the water is called an "ice dam" and can cause damage. Heat loss into your attic or roof assembly is usually the culprit. The solution is to keep your roof deck cold by sealing leaks between the house and the attic or roof assembly and making sure any duct work in the attic is sealed and insulated.

I've discovered that wood board ceilings (tongue-and-groove) are notorious leakers. The only way to seal them is by installing a sealed rigid air barrier behind the wood boards (such as taped drywall or foam boards), or by solidifying the rafter cavities with either cellulose or foam insulation.

You're also likely to find heat leaks between the house and attic at the gap between the framing and the chimney, plumbing chases, interior walls open to the attic, pull-down attic stairs, architectural soffits such as those over kitchen cabinets or over the tub/shower, and side attics in a cape-style house.

Resist the urge to add more ventilation to the attic since that can potentially worsen the problem.

Q. My house is drafty. What is the best way to correct that?

 A. Quick answer? Air sealing! But let's explore a little more. The first thing you want to do is identify where the drafts are coming from. Check around or between window panes or around the hole where the chimney goes into the attic. Each air leak requires a specific fix, which might be weather-stripping, caulk, expanding foam, or sheet metal and rigid foam insulation. And remember that fiberglass insulation is not an effective air barrier!

You might want to contact an energy auditor for help identifying the source of leaks in your house. He or she will perform an air leakage test using a "blower door." If you prefer, you can perform your own test using a smoke stick (incense) and noting the direction the smoke blows. Visit the Marketplace for a list of energy auditors in your area.

Q. A contractor recommended insulating our walls with blown-in cellulose. Isn?t that just chopped-up newspaper?

A. You're right about cellulose insulation - it is primarily recycled newspaper. But it's treated for flame and pest resistance and, when installed properly, it's actually more effective than fiberglass insulation. In general, cellulose offers better coverage because the small chunks can fill behind and between tight spaces in a wall or ceiling in a way that fiberglass insulation just can't. So your contractor gave you good advice.

Q. What type of insulation would you recommend using on pipes?

A.  You're smart to insulate your pipes. In warm weather, insulation keeps cold-water pipes from sweating. In cold weather it helps reduce heat loss from hot-water piping and may just help you avoid frozen pipes as well.

Insulation comes in a number of forms, but the best and, by far, the easiest to use is a closed-cell foam insulation which generally comes packaged in three foot lengths. Choose the right size for the pipe diameter. These slip-on pipe jackets are easy to install and cover the entire pipe surface, even when bent around corners. Tape the ends where the pieces meet using electrical tape.

Q. I'm concerned about protecting the pipes in my mobile home. Are there alternatives to heat tape?

A. Good question. I can tell you from experience that insulating the pipes alone will not prevent freezing. Instead, you want to create a sealed, insulated enclosure around the pipes that is connected to the heated living space. The better sealed and insulated the enclosure, the more successful you will be in keeping out the cold.

If you find that you still need to supply heat to prevent the pipes from freezing, use a thermostatically controlled heat cable that is inserted into the water pipe, not a heat tape that wraps around it - and definitely not a light bulb!