Considering home improvements? Jump on the bandwagon

Next March the Professional Remodelers Association will sponsor a home-improvement show at Rosemont Exhibition Hall near Chicago's O'Hare International Airport. On hand will be Bob Vila of Public Broadcasting's ''This Old House'' fame.

TV star Vila will hold homeowner seminars on how to upgrade your old house and get the best job at the least cost.

There are perhaps a dozen homeowner shows in the United States each year, according to Homer V. Lundeberg, managing director of the Professional Remodelers Association (PRA) in Chicago. If a show is within reasonable driving distance of your home, a few hours of time spent there could prove valuable.

The fact is, home improvement is a growing business. Last year, for example, homeowners spent more than $34 billion to upgrade their homes, reports the National Association of the Remodeling Industry (NARI). This year that figure is expected to rise by 15 percent, according to NARI. With the reviving economy, it could run even higher when all the figures are in.

Most of the money is spent on cosmetic remodeling, with only .0006 percent spent on energy-related products. Even so, the total home-improvement bill is headed straight up.

The professional home-improvement industry, excluding the home do-it-yourselfers, is about 10 percent ahead of last year, but if interest rates were to drop, predicts Mr. Lundeberg of Chicago's PRA, business might rise 30 to 40 percent in 1983.

There's that much work just waiting to be done to the country's aging housing stock.

After all, Lundeberg reasons, half of all US homes were built before 1950. As they are sold by current owners, new occupants often want to upgrade the kitchen , bath, garage, or perhaps the landscaping. All this is money in the bank to the home-improvement industry. Even if the work is done by the do-it-yourselfer, it's good news to the supply stores.

Want someone to do the work?

Mr. Lundeberg says the PRA gets hundreds of calls from homeowners wanting advice on how to be wary of poor contractors, avoid the traps, and get the best renovation job for the money. His organization is talking with the Better Business Bureau on ways to curb the phony advertising that too often hooks the homeowner.

While the industry asserts it has done a good job in routing out the ''bad guys,'' the fast-talking fly-by-nighters and suede-shoe operators still exist. It's easy for an unethical operator to cruise a neighborhood, rapping on doors and offering to do a job at a bargain price. Even if the price is right in line with the reputable firms, the material and workmanship may be poor.

Make sure you hire a company or worker experienced in the kind of job you want done. When the economy is down, new-home builders get into the home-improvement field, and some are less skilled in upgrading a building than in putting one up new.

Lundeberg's group puts out a pamphlet listing 14 points on how to avoid a bad deal. Here are some things to look for:

* Are the guarantees clearly stated in the contract? Make sure the contract doesn't leave a lot of blank spaces and is written in clear language to avoid any confusion later.

* Does the contract include all the oral promises made by the salesman when he was trying to get the job?

* Is the cost of the job clearly stated in the contract? Remember, any changes you request will jack up the price.

* Make sure you receive a readable copy of the contract with all the spaces filled in to your satisfaction. Even after signing the paper, you still have three working days to cancel the deal, according to federal law. Many homeowners are not aware of the law.

You can ask for the 14-point pamphlet by writing to the Professional Remodelers Association, 20 East Delaware Place, Chicago, Ill. 60611, and enclosing a stamped, self-addressed, business-size envelope. Or you can call the PRA at (312) 664-6541.

If you plan to do a home-improvement job yourself, make sure you don't get in over your head. Get some good, solid advice before you make a mistake that may be hard to correct and cost you money you had not planned to spend.