1. Expect a payback. Finishing a basement can be a good investment. According to cost versus value surveys conducted annually by Remodeling magazine, the average return on investment for a basement project nationally is currently around 75 cents on the dollar. And a basement project is also likely to add new functionality to your home: more bedrooms, more efficient storage, and more space to entertain.
2. Flex DIY muscle. Even though plumbing and wiring are best left to professionals, framing walls, installing insulation, and hanging drywall should be within the capabilities of experienced do-it-yourselfers. Remember to line up proper building permits first; failure to do so could result in delays.
3. Let there be light. Where possible, plan for windows and doors. Make sure openings are cut before other work begins, and seal off the rest of the house from the resulting masonry dust. Before creating any new windows or doors, have a building professional make sure the surrounding walls can take on the increased structural load.
4. Give everyone a hand. Create beautiful and safe access to your remodeled basement. Beef up walls supporting handrails, and keep handrails in place after the building inspector has signed off on the project.
5. Evaporate moisture worries. Merely installing a dehumidifier can actually create problems by drawing water through foundation walls. Ensure good drainage off your roof and away from your foundation, provide good ventilation of bathrooms and kitchens to the outside, and don't open windows during humid months. Along with breathable insulation, a vapor retardant should be installed between interior stud walls and floors, and between foundation walls and floor slabs.
6. Find solid footing. Not all flooring can be used in below-grade applications. Solid wood is one example -- even small fluctuations in moisture levels can cause buckling and splitting. Shop for products that can be used below grade while achieving the looks you want.
7. Look up -- to a finished ceiling. Look for drop-ceiling and other ceiling products that lend themselves to residential-scale design -- 12-inch squares, for example. An installed drywall ceiling is another good option, but remember that ceiling textures can easily flake off. Regardless of the ceiling you select, remember that the highest level of your basement ceiling is the same height as the lowest hanging pipe, duct, or wire.
8. Heat things up. Your home's heating, ventilating, and air-conditioning systems may have been installed based on upper-level requirements. Make sure a HVAC contractor validates that you have the right equipment to serve the basement as well. Otherwise, you may reduce equipment life span.
9. Rein in radon. Radon is an odorless radioactive gas that seeps into basements from surrounding soils. Uncontrolled, it can expose you and your family to the equivalent of 200 chest x-rays annually. Test for it with charcoal-base collectors, or hire a licensed radon contractor. Local utility companies may offer radon testing. Mitigating radon may involve sealing cracks and surfaces, or installing ventilators.
10. Have an escape route. Local building codes may demand egress windows in order for a basement room to be considered a bedroom, and an enclosed closet may also be required. Egress windows must be large enough for a firefighter in full gear to get into a burning house -- and for occupants to safely escape if stairways are blocked by fire. Another egress option is to add hinged outside access doors.