7. Find Cash in the Attic

It's almost always cheaper to repurpose existing space than to add square footage to your home. Spending the national average of about $48,000 to create a bedroom in the attic will net you around $36,000, or about 74 percent at resale, the CVR reports.

That price includes a 15' x 15' bedroom, a 5' x 7' bath with shower, a 15-ft. dormer, four windows and a closet. Can your existing HVAC system heat and cool another room? If not, budget for a second unit.

How much value an attic bedroom creates varies a lot between regions. You'll get a whopping 87 percent return on the West Coast, but only 67 percent of your money back at resale on an attic conversion in the Northeast.

More Smart Home Updates:

1. Spruce up or replace your siding.
2. Add a deck.
3. Tweak your kitchen.
4. Repair or replace windows.
5. Overhaul your kitchen.
6. Strip the bathroom.
7. Find cash in the attic.
8. Earn bucks from the basement.
9. Add space to add value.
10. Add low-cost landscaping.