Value of a Finished Attic

One important consideration for any remodeling project is the cost. Tied with that is the ROI (return on investment) when it comes time to sell the home. It’s rare to find a remodeling project with a 100% ROI, but finishing an attic is pretty far up there on the list. Over and above that, just like finishing a basement, it adds to the square footage of a home, bumping the price up even more.

Unfinished space, specifically unfinished basements and attics, is not counted in the total square footage of a home. That figure is only supposed to include living space, nothing more. Unfinished attics don’t qualify as “living space” but only as storage space. While that’s useful, it doesn’t add meaning to the home’s value.

How Big is the Attic?

Often, project costs and home values are expressed in cost or value per square foot. For an attic, this ranges from $50 to $200 per square foot. This wide range is predominantly due to the wide variety of ways that the attic can be finished and what can be done as part of the project.

How much space is available depends a lot on the size and floor plan of the home. Homes with a boxy appearance and perimeter will have more free space in the attic than ones where the exterior walls step in and out, with a broken-up shape to the roof. Single-story homes will have almost double the attic space available than two-story homes will.

However, the roof pitch is the most significant determining factor in the amount of attic space available. Homes with a steeply pitched roof have much more space in the attic than homes with a low pitch. The basic rule is that at least half of the finished room has a ceiling height of at least 7 feet, that this area be a minimum of 7 feet wide, and that it provides a minimum of 70 square feet of area with this 7-foot ceiling. This is considerably easier to accomplish with a steeply pitched roof than a low-pitched one.

Some homes are designed and built with the idea of the attic being finished. In that case, the attic space may already have dormers built in. However, the big difference this will make is that the home’s exterior walls will probably be taller than those of a typical single-story home. This allows the knee walls to be closer to the perimeter walls of the house, considerably increasing the square footage available for an attic conversion.

The average size of an attic finish is roughly 16’ x 17’. In some cases, a long, narrow, walk-in closet off of one side of this increases the available space.

Remodeling Costs to Finish an Attic

Before discussing how much value an attic finish adds to the home, let’s consider how much the job will cost. That can vary considerably, depending on the attic’s size and what’s included in the project. It’s obviously more expensive to do an attic if a bathroom is being included than if one is not required. Likewise, another big ticket item that can drive up the cost is having to add in a new HVAC system.

Looking at the costs of other attic finish projects, I can find a range from about $8,000 to $80,000. However, that higher price tag obviously includes all the bells and whistles, like a bathroom and a fancy closet with built-in storage. But a basic attic remodel, adding in a bedroom, shouldn’t be all that expansive.

Here are some basic cost estimates for various parts of the project. Please note that these are just approximations provided to give a rough idea. The particulars of how the attic will be finished and the condition of the house may cause these numbers to vary significantly.

• Architect and structural engineer – $3,000 to $10,000 
• Basic construction costs – framing, drywall, and subfloor – $3,000 to $18,000
• Floor covering – $2,000 to $6,000
• Installing a staircase – $2,000 to $6,000
• Installing floor joists (if the existing ones aren’t strong enough) – $2,000 to $10,000
• Insulating the attic – $1,500 to $3,000
• Adding a dormer – $2,500 to $10,000
• Adding skylights – $1,000 to $4,000
• HVAC system – $1,500 to $4,000
• Bathroom addition – $9,500 to $20,000 (or more, if it’s fancy)
• Electrical – $1,000 to $3,000

However, these prices assume the work will be done by subcontractors, with the homeowner acting as the general contractor. If a contractor is hired, they will probably do much carpentry work. Add about 15% of their fee to manage the project.

If the homeowner does this as a DIY project, the cost will be lower considerably. While it is hard to estimate how much, construction projects are typically about 60% materials and 40% labor. Remodeling jobs, on the other hand, flip those percentages to 40% materials and 60% labor due to the higher labor required for demolition and fitting things into an already existing home.

What this means is that doing the job yourself not only saves you money on the project but will pretty much ensure that 100% of the cost of the project will be recouped when the home is sold. There might even be some profit to help compensate for the time required to do the job.

How Much Does it Add to the Selling Price?

It’s hard to calculate in advance just how much a finished attic will add to a home’s value. By and large, it works out to about 60% of the cost of finishing it. But that figure is based on a contractor doing the work. So, the percentage works out to be higher than 60% if the homeowner does the work themselves.

Another way to look at it is to calculate a value based on the total square footage of the addition. Homes range in value from roughly $50 to $200 per square foot. To find what your home would sell for and compare it with comparable homes, look on one of the big real estate sites for similar homes in size, construction, and condition in the same area. Those home listings will also include a “price per square foot” for the homes. Assuming everything else is similar, the price per square foot should be about the same.

If the average attic finish is 16’ x 17’, that’s 272 square feet. At a price per square foot of $100, that adds $27,200 to the value of the home at selling time, at a minimum. But it might be even more if special features are added to the attic finish, like fancy woodwork, built-in cabinetry, and another bathroom.

Ultimately, the value it adds to the home depends on what the buyer is willing to pay for. The final price the home sells for is always a negotiated price, with both the buyer and seller having input into the agreement. The better the house looks and its condition, the higher the price it will sell for.