Pricing ranges
Attic conversions vary too much for a fixed cost calculator. Bay State uses the Preliminary Estimate path with three scope tiers. Final price is confirmed in your Preliminary Proposal after on-site consultation.
| Scope tier | Typical investment range | What's included |
|---|---|---|
| Basic scope | $45,000 – $75,000 | No dormers, no bathroom — finish work on existing attic with staircase already in place |
| Mid-range scope | $75,000 – $125,000 | May include either a dormer or a bathroom |
| Full-scope conversion | $125,000 – $175,000 | Full suite with dormers and a bathroom; may include structural modifications and a new staircase |
Top five cost drivers
- Dormers or roof-line changes — a single dormer can shift the tier of your project. Roof modification, new framing, exterior envelope. Triggers structural engineering, longer permit review, exterior finish work.
- New or replacement staircase — code-compliant access. Engineering during design, framing during construction, custom millwork lead time.
- Structural work for headroom — Massachusetts code requires a minimum 7 ft of headroom for living area. Often requires structural steel, ironwork, or load-bearing modifications. Steel fabrication adds 4 to 6 weeks.
- Adding a bathroom — plumbing rough-in (typically requires connection down to the main drain stack), tile, waterproofing, fixtures, ventilation. Adds plumbing and electrical inspections.
- Windows and skylights — quantity, size, product tier. Velux skylights run a different price point than fixed windows or custom dormers.
Process narrative
Ten-step client-visible flow: Sales, Design & Planning, Procurement, Construction, and Completion. The same phase names appear on your proposal, your schedule, and on the job site.
- Consultation Scheduled (Sales Phase) — pre-meeting questionnaire and a 30-minute call.
- Preliminary Proposal Sent & Preliminary Proposal Signed (Sales Phase).
- Site Measurement & Design Consultation (Design & Planning) — Validation Assessment for load-bearing walls and headroom verification.
- Material Selection Process (Design & Planning) — Part A take-off; Part B selections at the Bay State Kitchen Gallery showroom and vendor partners.
- Layout Development & Design Development & Presentation (Design & Planning).
- Final Proposal Sent, Negotiation & Contract Signed (Sales Phase).
- Design & Planning Summary Meeting (Design & Planning) — followed by Design & Planning Completion Gate.
- Permit Preparation & Submission (Design & Planning) — Long Form permit with stamped engineered drawings if structural work is involved.
- Project Mobilization & Execution Phase (Construction) — Post-Demolition Review & Decision Gate, Substantial Completion Walkthrough, Punch List Completion.
- Final Completion Walkthrough & Project Completion (Completion) — Project Completion & Satisfaction Form, Review Request & Referral Request.
Timeline by scope tier
| Scope tier | Typical duration | Includes |
|---|---|---|
| Basic scope | 3 to 4 months (on-site construction only) | No dormers, no bathroom — straightforward finish work |
| Mid-range scope | 4 to 6 months (design + permits + build) | May include a dormer or a bathroom |
| Full-scope conversion | 6 to 8 months (design + permits + build) | Dormers plus bathroom, structural modifications, or exterior changes |
What's included (scope)
Selection categories scale from 5-7 (basic finish) to 12-20+ (full primary suite with bathroom). Items unique to attic conversions versus single-room remodels:
- Roofing (when a dormer is added)
- Siding & exterior trim (when a dormer is added)
- Staircase — treads, risers, handrails, balusters, newel posts
- Custom millwork & built-ins — under-eave storage, knee wall cabinetry, window seats
- Velux skylights as a distinct selection from windows
Materials guidance
Attic guides do not use the Two-Source Model from the bathroom guide. Scope variability makes a fixed catalog impractical. The full selection list is built during the Material Selection Process in Design & Planning, tailored to what your project actually includes.
Top five selection-complexity drivers
- Whether a bathroom is added — adds seven categories at once (tile & stone, plumbing fixtures, bathroom vanities, countertops, cabinet hardware, accessories, glazing & mirrors).
- Dormers or roof-line changes — adds roofing and siding & exterior trim plus exterior paint and trim.
- Staircase scope — major standalone category (treads, risers, handrails, balusters, newel posts).
- Built-ins and custom millwork — under-eave storage, knee wall cabinetry, window seats.
- Whether a kitchenette, bar, or laundry is added — adds cabinets, countertops, appliances, cabinet hardware (most common in primary suite or guest suite scopes).
Photo placement (from the source guide)
Frequently asked
Why doesn't the attic guide have a fixed cost calculator like bathrooms?
Attic conversions have too many scope variables that dramatically shift pricing — dormers, structural modifications, bathroom additions, staircase replacement, and exterior changes each significantly swing both cost and schedule. The Preliminary Estimate path is used instead.
How is my actual price determined?
The tier ranges above are planning ballparks. Your specific Preliminary Proposal is prepared after our consultation and reflects your home's actual conditions, your scope goals, and your Client Selections at a reasonable budget tier.
Will my final price match my signed Preliminary Proposal?
Any scope adjustments are shown line by line in the Final Proposal.
What's the minimum headroom required for an attic to count as living space?
Massachusetts code requires a minimum of 7 feet of headroom for a space to qualify as living area. Achieving this often requires structural steel, ironwork, or load-bearing modifications.
How long will steel take?
Steel fabrication lead times typically run 4 to 6 weeks, and can become a scheduling bottleneck on attic projects that need it.
Will a dormer delay my project?
Yes — dormers add weeks to permit review (engineering required) and to construction (weather-dependent exterior work). A rainy fall or a cold winter can add further delay to exterior phases.
Can I use my new bathroom before the project is fully done?
Glazing and mirrors are measured and fabricated only after tile work is complete. They will not delay bathroom use upon main construction completion.
Ready to put this into practice?
A 30-minute consult is usually enough to confirm whether we are the right fit.
Book a consult