Depending on your home, insulation can make a big difference for a low cost — and older homes are especially likely to be poorly insulated. Check the insulation in your attic and any crawl spaces. If there’s no insulation or gaps in the insulation, it’s definitely time to add some.

You can install basic insulation yourself, even with minimal home improvement knowledge. Rolls of insulation are easy to find at any major home improvement store and installation can be as simple as cutting it to size and fitting it into place. Your home improvement store is likely to have how-to resources for you and will probably be happy to handle installation if you aren’t up for it. High-end foam or fiber insulation will offer better energy savings, but will require professional installation.

Checking the insulation in your home’s walls is a more complicated task — and a bigger project if you decide to replace it. You’ll want to consult a professional for either.