Q - I am interested in building an above-ground swimming pool myself to lower the cost. I want to use some type of inexpensive heating system to extend the swimming season. What are some do-it-yourself options? E. W.

A - Building a do-it-yourself swimming pool kit can greatly reduce the cost. You and a few friends should be able to build one in a weekend. Providing supplemental heat for the water, with solar, gas or electricity, can substantially extend the length of your swimming season.There are several options for keeping the water warm without doubling your summertime utility bills. A combination of do-it-yourself solar heat, a removable pool cover, and proper landscaping is effective.

Swimming pool solar systems are the easiest type to build yourself. Since they operate at relatively low temperatures, even very simple and crude systems can be effective and efficient.

There are above-ground swimming pool kits with a special deck that also functions as solar collectors. The deck is made of special hollow channels for the water flow, but it looks and feels just like an ordinary pool deck. Since the pool water flows through it and carries the sun's heat to the pool, the deck stays more comfortably cool on your feet.

Once you have assembled the pool and deck, you have the option of using the deck for the solar system. You just hook up a kit containing some valves and flexible hoses from the water filtration system to the deck. The filtration pump circulates the pool water through the deck.

If your pool water gets uncomfortably warm in the summer, you can also use the solar system to cool the water. By letting the pool water circulate through the collectors or deck at night, particularly on a clear night, heat radiates from the collectors to the sky.

Using a special plastic bubble-type swimming pool cover is another inexpensive heating method. Much pool water heat loss is from evaporation of the water. Covering the pool when it's not in use reduces the evaporation and allows the sun's heat to pass through into the water. This also reduces the amount of chemicals you have to add to the water.

You can plant low evergreen shrubs around the north and northwest sides of your pool. These shrubs block the force of the cooler fall and winter winds, but they won't block the sun from the south.

You can write to me for UTILITY BILLS UPDATE No. 372 for information on do-it-yourself solar deck systems, and lists of manufacturers of above-ground swimming pool kits, solar collectors of do-it-yourself systems, and bubbletype pool covers. Write to James Dulley, The Deseret News, 6906 Royal Green Dr., Cincinnati, OH 45244. Please include $1 and a self-addressed envelope.

Q - If you had to select the three best low-cost home energy improvements one can make himself, what would they be? T. H.

A - Each house is unique, so what may be best for one house may not be best for another. In general, setting your thermostat lower in the winter and higher in the summer is at or near the very top of the no-cost list.

Switching off lights when you leave a room saves a lot of money too. In addition to saving the electricity for the lights, your air-conditioning load will be less in the summer.

Installing a low-flow shower head or flow restrictor can save more than $100 dollars per year. You can buy a flow restrictor for about a buck.