DENVER -- Starting in April, new government rules will require contractors to take increased precautions on project sites that may contain lead paint.

Homes built before 1978 are covered under the new regulation. One contractor tells 7News that as many as 90 percent of the homes in Denver may fall into that category.

Contractors and other skilled workers will have to be certified in order to complete basic home repairs. In addition, extra supplies may be needed to mitigate the threat of lead paint dust. Those extra demands could raise costs.

In some cases, your bill could double, according to Charlie Simpson of Spectrum General Contractors in Denver.

With the possibility of a price increase, some contractors may try to exaggerate your bill. Simpson recommends you get references to make sure you are being quoted a fair price.