Flat Roof Replacement cost in San Francisco, CA
San Francisco, CA · updated August 2026
$21,900
Typical local cost
$9,700 – $45,400
Typical range
- per sq ft of roof area
- $9.50 – $26
- Permit
- Yes
- Typical timeline
- 2-5 days of work
Installed, local pricing
$285 – $1,100 in fees
2-5 days of work, 2-6 weeks including permitting
San Francisco runs +62% against the U.S. average · data confidence High · modeled estimate, not a quote
The modeled midpoint for San Francisco is $21,900. The local adjustment for this trade is x1.620 — driven mainly by San Francisco County labor rates and 90% exposure to local code requirements.
Estimate your San Francisco job
Priced with this market's cost index, so the calculator, the size table and the ranges on this page all agree.
Roofing squares needed
14.8
Includes 10% waste
- Roof area
- 1,344 sq ft
- Shingle bundles
- 45 bundles
- Underlayment rolls (4 sq)
- 4 rolls
Priced for San Francisco (local adjustment x1.620).
Estimates only. Local pricing, site conditions and code requirements change the real number.
Cost by project size
Generated from the same unit pricing the calculator uses.
| Project size | Estimated range |
|---|---|
| 700 sq ft of roof area | $6,700 – $18,200 |
| 1,000 sq ft of roof area | $9,500 – $26,000 |
| 1,200 sq ft of roof area | $11,400 – $31,200 |
| 1,600 sq ft of roof area | $15,200 – $41,600 |
| 2,100 sq ft of roof area | $20,000 – $54,600 |
Based on San Francisco pricing of $10–$26 per sq ft of roof area.
Cost by roof scope
Roof pricing moves on area, pitch, how many layers come off and what the deck looks like underneath. Every row is priced against the San Francisco median.
| Scope | What it includes | Typical installed cost |
|---|---|---|
| Overlay on a simple ranch roof | Single layer, 4:12 pitch, no tear-off | $13,600 – $18,000 |
| Standard tear-off and replace | One layer removed, architectural shingle, walkable pitch | $18,600 – $25,200 |
| Two-layer tear-off | Extra removal and disposal, same footprint | $21,900 – $29,600 |
| Steep or cut-up roof | 8:12+ pitch, multiple valleys, dormers, staging | $27,400 – $37,200 |
| Replacement with deck repair | Partial resheathing found after tear-off | $25,200 – $35,000 |
- • Tear-off and disposal is priced per layer — quotes that omit a second layer are the most common source of change orders.
- • Decking is unknown until the old roof is off. Reputable quotes state a per-sheet resheathing price up front.
- • Pitch above 7:12 requires fall protection and slows the crew, which shows up as labor, not material.
Basis: Each scope is priced as a multiple of the modeled San Francisco median for flat roof replacement, so the scenarios, the size table and the calculator always agree. · Hometriva methodology
Cost by material
Installed cost in this market, with expected service life.
| Material | Installed range | Lifespan | Maintenance |
|---|---|---|---|
| Standing-Seam Metal Roof | $32,900 – $52,600 | 40–70 yrs | Very low |
| TPO Membrane | $18,600 – $27,400 | 18–25 yrs | Low |
Where the money goes
- Labor
- $12,000
- 53% of median
- Materials
- $9,900
- 44% of median
- Permit & fees
- $695
- 3% of median
San Francisco project costs+62% vs U.S. average
Based on San Francisco County labor rates, local material logistics and permit-fee posture for this trade.
What the project looks like start to finish
Typical sequence for this scope. Timing varies with contractor backlog and plan-review queues.
01
Planning & quotes
Scope, material choice, contractor selection
02
Permit application
Filed with San Francisco Department of Building Inspection
03
Materials & staging
Order lead time on non-stock materials
04
Installation
2-5 days of work, 2-6 weeks including permitting
05
Inspection
Dry-in inspection, In-progress attachment, Final roof inspection
06
Closeout
Final sign-off, warranty and documentation
San Francisco labor intelligence
What the trade charges here, and how much of your price it is.
Loaded hourly rate
$89–$115
Exterior crews in San Francisco County · +48% vs U.S. ($68/hr)
Typical crew
3 × 5 days
On-site time for a typical flat roof job here.
Labor in the price
$12,000
55% of the median — the rest is material, disposal and permit.
Because labor is 55% of this job, San Francisco wage levels move the price far more than material prices do. A quote well under this labor figure usually means a smaller crew, a longer schedule, or unlicensed help.
Basis: Hometriva labor model: national exterior crew rates adjusted by the San Francisco County labor factor (x1.481). · BLS Occupational Employment and Wage Statistics, Hometriva methodology
Why San Francisco differs from the national average
The local delta, broken into dollars by driver.
Trade labor rates+$3,575
San Francisco County crews price 48% above the national average, and labor is 55% of this job.
Code and inspection load+$2,525
Flat Roof Replacement carries 90% exposure to local code requirements, and this jurisdiction's review load indexes at x1.21.
Material and delivery+$1,350
Materials are nationally traded, so they move less — but delivery into this market runs 22% over baseline.
Permit fees+$250
Fees are paid to the jurisdiction, not the contractor, and are budgeted separately from the contract price.
Basis: Decomposition of the modeled San Francisco median against the U.S. median for this scope. · San Francisco Department of Building Inspection, Hometriva methodology
San Francisco vs California vs the U.S.
Change the inputs, see your number
The same local model, run against your job instead of the average one.
Simulated flat roof replacement in San Francisco
$22,595
Likely range $10,395 – $46,095
Simulated from the same local model as the numbers above — it changes the inputs, not the pricing method.
What makes the number move
- Membrane type: modified bitumen, TPO or coating
- Tapered insulation to correct ponding
- Number of penetrations and curbs
- Tear-off layers
- Parapet and flashing detail work
Who issues each permit
Tracked per discipline — the building permit issuer is not always the body that reviews electrical, plumbing, zoning or fire.
| Discipline | Issuing authority |
|---|---|
| building | San Francisco Department of Building InspectionConfirmed department |
| electrical | San Francisco Department of Building InspectionConfirmed department |
| mechanical | San Francisco Department of Building InspectionConfirmed department |
| plumbing | San Francisco Department of Building InspectionConfirmed department |
| zoning | San Francisco Department of Building InspectionConfirmed department |
| fire | San Francisco Department of Building InspectionConfirmed department |
Permit requirement in San Francisco
Yes — a permit is required for flat roof replacement in San Francisco, CA. The work must be inspected before it can be closed out, and a licensed contractor generally has to pull the permit.
- Permitting authority
- San Francisco Department of Building InspectionConfirmed department
- Permit fee
- Based on declared project valuationSan Francisco is a consolidated city and county; DBI issues and inspects building permits citywide. Typical range for this scope: $285–$1,100.
Inspections
- Dry-in inspection
- In-progress attachment
- Final roof inspection
Local conditions that change this job
Only the exposures that materially affect flat roof replacement.
Cooling load / heat exposure
Severe82/100
Annual rainfall
High74/100
Named-storm exposure
High70/100
Solar irradiance
Severe82/100
San Francisco sits in San Francisco County, California. Seismic bracing, energy-code (Title 24) compliance and coastal exposure all factor into permit scope and material selection. Work outside city limits is permitted by the county building department rather than the city.
Nearby market comparison
+ Had flat roof replacement done in San Francisco? Add what you paid or were quoted
Reports are reviewed before they count, and nothing is published until at least 5 reports exist for a market. No name, email or address is collected.
How Hometriva estimates San Francisco flat roof costs
Hometriva does not publish invented city prices. The San Francisco estimate for flat roof replacement is produced by this chain, and every input is stored separately:
- National baseline$13,500
Typical U.S. cost for flat roof replacement on a single-family home.
- Local labor factorx1.481
San Francisco-area trade labor rates, weighted at 55% of this job.
- Material factorx1.222
Material and delivery pricing into San Francisco County, weighted at 45%.
- Regulatory factorx1.208
Local code, product-approval and inspection load, applied at 90% for this project type.
- Applied multiplierx1.620
Blended San Francisco adjustment specific to flat roof replacement.
- Permit component$285 – $1,100
Budgeted separately from the contract price because it is paid to the jurisdiction.
Because labor, material and regulatory factors are weighted per project, flat roof replacement in San Francisco carries a different local adjustment than other trades in the same market.
Reviewed by
Hometriva Cost Data Desk
Maintains the unit-cost baselines, local adjustment factors and material pricing. Reviewed for flat roof replacement pricing in San Francisco, CA.
- • National unit-cost baselines against current trade pricing
- • Local labor and materials factors for the market
- • Material installed-cost ranges and service life
Last reviewed August 2026 · Editorial standards · Report an error
Frequently asked questions
Do I need a permit for flat roof replacement in San Francisco, CA?
In most jurisdictions this work is permitted and inspected. Requirements are set locally, so confirm the current application and inspection checklist with your building department before work starts.
How long does flat roof replacement take?
2-5 days of work, 2-6 weeks including permitting. Permit review and inspection scheduling are usually the largest source of variation.
What changes the price the most?
The largest cost drivers are membrane type: modified bitumen, tpo or coating; tapered insulation to correct ponding; number of penetrations and curbs.
Sources
Sources & verification
- San Francisco Department of Building Inspection
- California Building Standards Commission
- BLS Occupational Employment and Wage Statistics
Model vintage August 2026. The links above are the issuing agencies' own pages — we publish them so you can confirm the current rule yourself, not as evidence that each fact on this page was re-checked with them today. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing, not quotes. Permit rules change; confirm with the building department before starting work.