QUESTION: I want to build an inexpensive greenhouse from scratch or from a kit for growing plants organically. I want to make it efficient so it needs as little extra heat as possible. What design do you recommend?ANSWER: I would recommend buying a do-it-yourself kit instead of trying to build your own greenhouse from scratch for several reasons. By the time you purchase all the materials to build one from scratch, you may end up paying more than you would have for a simple kit which has more features.A kit will be more stable than one you build yourself from scratch using a lumber frame. With the high level of humidity and exposure to the sun, wood is not the optimum framing material. Most kits use plastic, aluminum or galvanizing steel framing which is not affected by humidity.The plastic frame models, such as Aarons Creek Farms, are glued together similar to plumbing.Unless you live in a very mild climate, your greenhouse will likely need some supplemental winter heating for year-round use. It is better to plan to use the greenhouse in all but the coldest months to avoid heating it. By making it efficient, you may be able to use it 10 or 11 months per year.Since you are looking for an inexpensive greenhouse option, a kit which uses a polyfilm covering would be an excellent choice. The polyfilm allows a high percentage of the sun's heating rays to pass through into the greenhouse and it is more durable than you might think.In very hot, sunny areas, consider installing a kit with white polyfilm on the top and clear polyfilm on the sides. The white polyfilm allows only about 55 percent of the sun's rays to pass through to avoid burning the foliage and summertime overheating. The clear sides allow indirect light and heat to enter.The polyfilm used in most kits is four or six mils thick. It should contain ultraviolet light inhibitors for a longer life. When you order a polyfilm sunroom, consider getting a patching kit with it. It is easy to repair any small tears and, to be sure, you should expect to damage a few spots.Another common, but more expensive option, is a rigid double-wall polycarbonate plastic covering. This is extremely strong, and with the double wall design, it provides more insulation to keep heat inside the greenhouse. Glass is the best material to use, but it is probably outside your budget.You can improve the greenhouse efficiency by using a gravel, stone or brick floor. This adds thermal mass to store the sun's heat. If possible, install an attached kit on the south side of your house so it already has one heated wall.The following companies offer greenhouses and kits: Aarons Creek Farms(888-888-9050 www.littlegreenhouse.com), Atlas Greenhouse (800-346-9902 www.hobbygreenhousekits.com), Hoop House (800-760-5192 www.hoophouse.com), Sunshine Gardenhouse (888-272-9333 www.gardenhouse.com), and Yard Works (800-369-8333 www.yardworks-greenhouses.com).Send inquiries to James Dulley, Butler Eagle, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.

QUESTION: I have many of the little transformers that plug into the wall for telephone machines, speakers, lights, etc. Some of them seem to feel warm all the time. Are they wasting electricity continuously?ANSWER: Most homes have many of those little devices and they do continuously use electricity even when the appliance or light is not on.Each one uses very little, but the total electricity wasted by many of them in a month can be significant.Unplug ones for seldom used items. For other frequently used ones, plug them into an outlet strip which has an easily accessible on-off switch.James Dulley has a degree in mechanical engineering. His Sensible Home column appears in 400 newspapers.