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Attic conversion cost: turning an attic into a bedroom

Turning 323 sq ft of attic into a finished bedroom typically costs $35,000, with most projects between $27,300 and $45,500 before sales tax. That covers permits and engineering, strengthened floor joists, insulation and drywall, a code-compliant staircase, an egress window, a skylight, wiring and a ductless mini-split. A simpler finish runs about $31,300, while a higher-spec conversion with a full bathroom, better insulation and hardwood floors is around $62,000. Add a shed dormer or gable dormers in the calculator if you need more headroom.

Most homeowners pay

$27,300 – $45,500National average · 323 sq ft · before sales tax
Typical: $35,000
Labour $19,293Materials $15,741Work hours: 252.8

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sq ft
Regional estimate

Compare materials

mid-range, typical

Cost by region

Alabama: $31,400Alaska: $39,700Arizona: $33,700Arkansas: $30,900California: $38,800Colorado: $35,600Connecticut: $36,800Delaware: $34,300District of Columbia: $36,600Florida: $32,100Georgia: $32,800Hawaii: $43,700Idaho: $32,500Illinois: $40,300Indiana: $34,900Iowa: $33,800Kansas: $32,800Kentucky: $32,600Louisiana: $32,200Maine: $35,600Maryland: $35,700Massachusetts: $39,700Michigan: $35,600Minnesota: $37,500Mississippi: $30,800Missouri: $35,400Montana: $35,300Nebraska: $32,500Nevada: $34,900New Hampshire: $36,000New Jersey: $38,300New Mexico: $33,700New York: $38,300North Carolina: $31,700North Dakota: $34,200Ohio: $35,300Oklahoma: $31,400Oregon: $37,700Pennsylvania: $35,300Rhode Island: $34,800South Carolina: $31,900South Dakota: $32,100Tennessee: $32,200Texas: $31,900Utah: $32,900Vermont: $35,600Virginia: $33,800Washington: $39,700West Virginia: $32,700Wisconsin: $35,800Wyoming: $33,200
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LocationBasicMid-rangePremium
Hawaii$38,600$43,700$74,200
Illinois$36,300$40,300$74,000
Alaska$35,500$39,700$72,400
Massachusetts$35,500$39,700$72,300
Washington$35,500$39,700$70,100
California$34,700$38,800$67,800
New Jersey$34,200$38,300$68,200
New York$34,400$38,300$68,000
Oregon$33,700$37,700$70,600
Minnesota$33,700$37,500$70,000
Show all regions
Connecticut$33,000$36,800$66,200
District of Columbia$32,900$36,600$70,000
New Hampshire$32,200$36,000$63,500
Wisconsin$32,100$35,800$65,800
Maryland$32,000$35,700$62,900
Colorado$31,900$35,600$62,600
Maine$31,800$35,600$62,600
Michigan$31,900$35,600$65,400
Vermont$31,800$35,600$62,300
Missouri$31,600$35,400$62,800
Montana$31,600$35,300$65,000
Ohio$31,500$35,300$62,100
Pennsylvania$31,600$35,300$63,000
Indiana$31,400$34,900$63,900
Nevada$31,300$34,900$61,400
Rhode Island$31,400$34,800$63,900
Delaware$30,900$34,300$61,400
North Dakota$30,900$34,200$60,900
Iowa$30,300$33,800$60,600
Virginia$30,200$33,800$60,000
Arizona$30,300$33,700$60,200
New Mexico$30,100$33,700$60,000
Wyoming$29,800$33,200$59,500
Utah$29,500$32,900$59,200
Georgia$29,200$32,800$58,300
Kansas$29,600$32,800$59,600
West Virginia$29,200$32,700$58,200
Kentucky$29,300$32,600$59,300
Idaho$29,200$32,500$57,100
Nebraska$29,100$32,500$58,500
Louisiana$28,900$32,200$58,700
Tennessee$28,900$32,200$57,800
Florida$28,800$32,100$56,800
South Dakota$28,800$32,100$56,600
South Carolina$28,700$31,900$56,700
Texas$28,600$31,900$57,700
North Carolina$28,500$31,700$57,100
Alabama$28,100$31,400$57,000
Oklahoma$28,200$31,400$56,800
Arkansas$27,700$30,900$54,800
Mississippi$27,700$30,800$55,700

What's included

Mid-range

What affects the cost

Headroom

Under the International Residential Code, at least half of a room with a sloped ceiling needs 7 ft of height, and no required floor area can be under 5 ft. Attics with steep roofs often pass; shallow roofs need a dormer or a raised roof, which changes the budget completely.

Stairs

A pull-down ladder does not count as access to a bedroom. The new stair has to land somewhere on the floor below, which often means giving up part of a hallway or closet and reframing the opening.

Floor structure

Attic floors were framed as ceiling joists, not for living loads. Most conversions add sistered or new joists and a subfloor, and an engineer decides how much reinforcement is needed.

Dormers

A shed dormer is the most efficient way to add usable floor space and headroom along one side. Gable dormers look more traditional on the front of a house but add less floor area for the money.

Heating and cooling

Attics run hot in summer, so plan for real cooling. A ductless mini-split is the usual answer; extending the existing ductwork works only if the system has spare capacity.

Bathroom

Adding a bathroom is the single biggest extra because drain, vent and supply lines have to reach the attic. Placing it above an existing bathroom keeps the plumbing runs short.

How to save

  • Check headroom before paying for plans: if you need a dormer or a raised roof, the numbers change a lot.
  • Put a bathroom directly above an existing one, or leave it out and add a half bath later.
  • Use a ductless mini-split rather than new ductwork from a basement furnace.
  • Get fixed prices for the stair, egress window and joist reinforcement, which are the items that vary most between bids.

Grants, tax and rules

Code and permits

A finished attic bedroom is new living space, so it needs a building permit, plus electrical, mechanical and plumbing permits for that work. Under the International Residential Code, which most areas adopt with local changes, a habitable attic and every bedroom need an emergency escape and rescue opening, and at least half of a sloped-ceiling room must have 7 ft of height.

Sales tax

Sales tax on materials varies by state; labor is often not taxed, but rules vary. Our figures are before sales tax.

Frequently asked questions

How much does it cost to convert an attic into a bedroom?

For about 323 sq ft of attic with a new staircase, egress window, skylight, insulation, drywall and a mini-split, expect around $35,000 before tax. A simpler finish is about $31,300, and a conversion with a full bathroom and higher-end finishes is around $62,000.

Does an attic bedroom need an egress window?

Yes. The International Residential Code requires an emergency escape and rescue opening in habitable attics and every sleeping room. In an attic it usually goes in a gable wall or the face of a dormer.

How much headroom do I need to finish an attic?

Under the IRC, at least 50% of the room's required floor area needs a 7 ft ceiling and none of it can be under 5 ft. Measure from the top of the future finished floor, not from the existing joists.

How much does a dormer add?

Pick a shed dormer or two gable dormers in the calculator to see the extra for your size. A shed dormer usually adds the most usable floor space per dollar.

How long does an attic conversion take?

Plan on six to ten weeks of work once permits are issued, longer with dormers or a bathroom. The noisiest weeks are the stair opening and the joist work.

Is an attic conversion cheaper than an addition?

Usually yes, because the roof and foundation already exist. The trade-off is sloped ceilings, stair space taken from the floor below and the need to cool the space properly.

How this estimate is calculated

Work hours: 252.8 · Labour: $19,293 · Materials: $15,741

Sources: BLS Occupational Employment and Wage Statistics; Regione Toscana, Prezzario dei Lavori 2026 (CC BY 4.0); ECB exchange rates; market check: Attic bedroom ~320 sq ft, new stair, egress window, skylight, mini-split, before tax. HomeGuide cost to finish an attic (2026: bedroom/bonus room $20-45k, $50-150/sq ft); Block Renovation attic renovation guide (20 Jul 2026: 550 sq ft bedroom conversion $43,900 incl. stair, egress, joists).

Last reviewed September 26, 2026 · How we calculate costs · Editorial policy