10 most valuable home improvements

Converting an attic into a bedroom

The biggest mover in this year’s survey is renovating unused attic space into an additional bedroom. This renovation moved up three spots for 2014. The average cost is $49,438 and adds $41,656 in value — 84.3% of what you'll pay.

"The beauty of converting attic space to living space is you don’t have to then pay for foundation work," says Darren Vollmer, a partner with TrimCraft Builders of Madison, Wisc. This translates into being able to dedicate more of your budget toward finishing touches and furnishings.

Although some attics are large enough to be converted to a bedroom as is, others may require a dormer to achieve the needed space. To meet code requirements, you'll need a stairway, Vollmer says.

One of the biggest-ticket items is insulation, Vollmer says, since old attics are typically poorly insulated. But once the space is remodeled, your home will suffer less heat loss and, subsequently, fewer damaging ice dams on the roof.

Source: Remodeling 2014 Cost vs. Value Report (www.costvalue.com).