Attic bedroom costs and value

Converting an attic to a bedroom is a good investment, especially with the right type of attic insulation. According to Remodeling Magazine’s annual Cost vs. Value Report, an attic bedroom conversion that includes a small bath retains about 84% of its value. Plan on spending $150 to $200 per sq.ft.

But just because adding an attic bedroom under your rafters is a smart money move, it may not be practical or even doable. To determine if an attic bedroom is right for you, consider:

  • Building codes
  • Support structures
  • Electrical, HVAC, and plumbing systems
  • Access

Are building codes on your side?

Although home owners often consider building codes to be obstacles, safety and durability are the real missions of codes. Because local codes vary, your building inspector can provide a list of applicable codes and required inspections for your new attic bedroom.

  • Ceiling codes: Generally 7 feet 6 inches high over a minimum floor area of 70 sq. ft. If you have an attic shorter than required by code, you won’t be able to remodel it into living space.
  • Joist codes: Ask an architect or structural engineer if your attic floor joists meet local codes and can support the additional weight of a remodeled space. Also ask if the rafters can support drywall, lighting, electrical, plumbing, and HVAC system components. Consultation costs $50 to $150 per hour.
  • Egress codes: Regular bedroom egress codes typically require at least two exits — a doorway and usually a window. An attic bedroom requires both a window and a staircase to the level beneath. Having an escape ladder in clear view is always a good idea.

Support systems

The structural framing beneath your roof — rafters or trusses — will determine if you can add an attic bedroom and what it might look like.

Rafters, internal beams extending from the peak of the roof to its eaves, provide a center open space that you can readily remodel.

Trusses, W-shaped framing that supports the roof, make things harder. To achieve the attic bedroom you want, you might have to cut through, shore up, and otherwise alter the very structures that keep your roof above your head. It may not be practical. Consult a structural engineer and/or a licensed architect to determine if modifying trusses is a good idea.

Extending systems to your attic bedroom

  • Electrical: Consult a licensed electrician to determine if your electric panel has room for additional breakers and can handle the increased load of an attic bedroom. If your system can handle the additional demands, running wires to the attic is relatively simple.
  • Plumbing: Cut costs by locating the new bathroom close to the main stack—large pipes that carry wastewater to your sewer or septic tank. This reduces the length of pipe you’ll run between sink-shower-toilet drains and the stack.
  • HVAC: An HVAC specialist will tell you if your forced air blower can move enough air to both heat and cool your attic bedroom. If it doesn’t, electric baseboard heating and a window air conditioner may suffice. Be sure your electrician knows your heating and cooling plans to determine the total electrical requirements of your new attic bedroom.

Gaining access

An attic bedroom requires a standard staircase to meet code; a ladder is insufficient. Adding a staircase will take up space in a room below the attic, so consider converting a closet. You may be able to regain that storage space by using space under the new staircase.

Staircases with straight runs are easiest to construct but take up the greatest area, just over 40 sq. ft. Depending on materials and finishing touches, such as newel posts and hardware, costs can range from $500 to $3,000.

Spiral staircases take up the least area but are typically more expensive. Prices for a wood or metal-wood staircase kit ranges from $2,000 to $6,000; installation ranges from $600 to $1,200.

If you’re short on inside space, exterior access — a staircase outside the house — may be a solution. Check with your zoning department, which may interpret an outside staircase as a sign of a multi-unit dwelling, which may not meet neighborhood zoning requirements.