By Alexander Georges · Last updated April 26, 2026

Attic Conversion Checklist

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Plan & Permits

Structural assessment

Hire a structural engineer to evaluate floor joists, roof trusses, and load-bearing capacity.

Check egress requirements

Code requires a window or door for emergency escape, plus minimum ceiling height of 7'.

Apply for permits

This is a major conversion requiring building permits, electrical, plumbing, and HVAC approvals.

Set detailed budget

Budget $25,000-$75,000 depending on size, dormers, and finishes. Add 20% contingency.

Measure headroom & space

You need 7' ceiling height over 50% of floor area. Measure ridge height and rafter angles.

Review financing options

Consider home equity loan, HELOC, or cash-out refinance to fund this major project.

Access & Egress

Plan stairway access

Full-height stairs need 10-12 feet of floor space below. Spiral stairs save space but limit furniture.

Determine egress window location

Position egress window to meet code while maximizing usable floor space and exterior aesthetics.

Install egress window

Cut opening, frame, install window, flash properly, and add interior trim. Critical safety feature.

Build staircase

Frame opening in floor below, install stringers, treads, risers, and railings per code.

Inspect access routes

Have building inspector verify stair dimensions, headroom, handrails, and egress window before closing walls.

Structure

Reinforce floor joists

Sister new joists to existing or add engineered beams to support living space load requirements.

Add support columns if needed

Some designs require posts from attic through lower floor to foundation for load transfer.

Build knee walls

Frame short walls where ceiling slopes meet floor, typically 4-5 feet high. Creates usable space.

Install collar ties

Horizontal beams connecting opposite rafters prevent roof spread under load. May already exist.

Frame interior walls

Build partition walls for bedroom, bathroom, closet, or office layout. Follow floor plan.

Structural inspection

Schedule inspection of framing, joists, headers, and connections before insulation or drywall.

Dormers

Plan dormer size & style

Shed, gable, or eyebrow dormers add headroom and light. Engineer must approve structural design.

Cut roof opening

Remove shingles, cut rafters, install headers. This requires experienced framing crew.

Frame dormer structure

Build walls, install rafters, ridge board, and headers. Tie into existing roof structure.

Install dormer roofing

Sheath with plywood, add underlayment, flash valleys, install shingles to match existing roof.

Side and trim dormers

Install siding to match house, add trim boards, paint or stain. Weatherproof exterior.

Mechanical

Run electrical wiring

Plan outlets every 12 feet, dedicated circuits for HVAC, lighting, smoke detectors. Hire electrician.

Extend HVAC system

Attic space needs heating and cooling. Options: extend existing ducts or add mini-split system.

Plan ventilation

Maintain attic ventilation in eaves/rafters to prevent moisture and heat buildup. Critical detail.

Install insulation

R-38 to R-60 in ceiling, R-19 to R-30 in walls and floors. Air-seal thoroughly before insulating.

Mechanical inspection

Inspector checks electrical, HVAC, insulation, and ventilation before covering with drywall.

Drywall & Ceiling

Hang drywall on ceilings

Start with ceiling, use 5/8" for flat areas, follow rafters on slopes. Lift or scaffolding required.

Hang drywall on walls

Install 1/2" drywall on knee walls and partition walls. Cut carefully around outlets and windows.

Tape and mud seams

Apply joint compound in 3+ coats. First coat embeds tape, second feathers, third smooths.

Sand drywall smooth

Lightly sand with fine grit after final coat. Wear dust mask. Vacuum thoroughly.

Flooring & Trim

Install subfloor

Lay 3/4" tongue-and-groove plywood or OSB over joists. Glue and screw every 6-8 inches.

Install finish flooring

Carpet, hardwood, or luxury vinyl plank. Consider weight and sound transmission to below.

Install baseboards

Add 5-7 inch baseboards to cover drywall/floor gap. Paint before installing for clean finish.

Trim windows and doors

Install casing around windows and doors. Use rosettes at corners or miter joints.

Add built-ins and closets

Maximize awkward sloped spaces with custom shelving, closet systems, or built-in storage.

Finishing

Prime and paint walls

Prime all drywall, then two coats of quality paint. Light colors make space feel larger.

Install light fixtures

Add recessed lights, ceiling fixtures, sconces. Use LED bulbs. Consider dimmer switches.

Install outlet and switch covers

Add cover plates to all outlets, switches, and data/cable jacks. Match finish to hardware.

Add window treatments

Curtains, blinds, or shades for privacy and light control. Consider energy efficiency.

Final inspection

Building inspector reviews completed work: electrical, egress, railings, smoke detectors, HVAC.

Document completed conversion

Take professional photos of finished space. Update home insurance. Increase property value assessment.

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