Kefiw · Property Improve
Methodology
How the roof-cost calculator in Property Improve produces its low/typical/high range, what's included and excluded, and why two homes on the same street legitimately get different quotes.
Cost engine version 2026.04 · last updated 2026-04-24.
Data sources
- Material cost per square. Set from current South-region distributor pricing for each material grade. Brackets brand and warranty-tier variation within the band.
- Labor cost per square. Set from working-crew bid-day economics in the Houston market: lead, two installers, helper, plus overhead. Specialty crews (metal, tile) carry their own band.
- Tear-off and dump fees. Per-square pricing reflects current Texas/Gulf-region landfill tipping fees and crew time per layer.
- Decking replacement. Per-square-foot pricing reflects 7/16″ OSB or 1/2″ plywood at current lumber-yard pricing plus install labor.
- Permit and dump-fee profiles. City-level permit ranges set from published municipal fee schedules and recent Eurocraft pulls. HVHZ markets (Miami) carry a structural-review and inspection premium.
- Regional multipliers. Applied to the subtotal. Reflects relative labor wages and material-delivery costs vs the Houston baseline.
Formula
The total range is built piece by piece, then a region multiplier is applied:
squares = roof_sqft / 100
material = squares × material_$/sq
labor = squares × labor_$/sq × pitch_mult × story_mult × complexity_mult
tear_off = squares × tearoff_$/sq × layers
decking = roof_sqft × risk_share × decking_$/sqft
penetrations = count × $/penetration
permit = jurisdiction-specific flat range
warranty_add = (subtotal_ex_permit) × (warranty_mult − 1)
subtotal = material + labor + tear_off + decking + penetrations + warranty_add + permit
total = subtotal × region_multEach line carries a low and a high. The headline range is the sum of lows × region.low through sum of highs × region.high. Typical is the midpoint — not the most-likely outcome, just the math midpoint. Most legitimate bids will land inside the range; bids well outside it deserve a question.
Pitch labor multipliers
| Pitch band | Low | High |
|---|---|---|
| Low (3:12 – 6:12) | ×1.00 | ×1.05 |
| Medium (7:12 – 9:12) | ×1.10 | ×1.20 |
| Steep (10:12 – 12:12) | ×1.30 | ×1.50 |
| Very steep (>12:12) | ×1.55 | ×1.85 |
Complexity labor multipliers
| Complexity | Low | High |
|---|---|---|
| Simple gable (few cuts, no dormers) | ×0.95 | ×1.00 |
| Standard hip (typical suburban) | ×1.00 | ×1.05 |
| Complex (multiple gables, dormers, valleys) | ×1.10 | ×1.20 |
| Cut-up (heavy dormers + many penetrations) | ×1.25 | ×1.40 |
Material catalog
| Material | Material $/sq | Labor $/sq | Lifespan |
|---|---|---|---|
| Asphalt — 3-tab | $85–$115 | $140–$200 | 15–20 yr |
| Asphalt — architectural / dimensional | $130–$185 | $180–$260 | 25–30 yr |
| Asphalt — designer / luxury | $280–$420 | $220–$320 | 30–40 yr |
| Metal — corrugated / exposed fastener | $380–$620 | $320–$460 | 30–45 yr |
| Metal — standing seam | $700–$1100 | $420–$620 | 40–60 yr |
| Tile — concrete | $300–$500 | $480–$720 | 40–50 yr |
| Tile — clay (Spanish / barrel) | $700–$1100 | $540–$820 | 50–75 yr |
Permit jurisdictions
| Jurisdiction | Permit + dump fees |
|---|---|
| Houston / Harris Co. TX | $250–$600 |
| Dallas / DFW TX | $300–$700 |
| Austin TX | $400–$900 |
| San Antonio TX | $200–$500 |
| Atlanta GA | $250–$650 |
| Tampa / Orlando FL | $350–$850 |
| Miami FL (HVHZ) | $600–$1500 |
| Charlotte NC | $250–$600 |
| Nashville TN | $250–$600 |
| Other South / unsure | $250–$800 |
Regional multipliers (vs Houston baseline)
| Region | Low | High |
|---|---|---|
| Houston | ×0.98 | ×1.02 |
| Dallas / DFW | ×0.98 | ×1.04 |
| Austin | ×1.05 | ×1.12 |
| San Antonio | ×0.93 | ×0.99 |
| Atlanta | ×0.95 | ×1.02 |
| Tampa / Orlando | ×1.00 | ×1.10 |
| Miami (HVHZ) | ×1.10 | ×1.25 |
| Charlotte | ×0.95 | ×1.02 |
| Nashville | ×0.95 | ×1.02 |
| Other South | ×0.95 | ×1.10 |
What's included
- All material with normal waste factor
- Labor for tear-off, decking-rot replacement (probabilistic), install, cleanup
- Underlayment, starter, drip edge, ridge cap as part of material $/sq
- Standard flashing replacement at penetrations
- Permit and disposal fees
- Workmanship-warranty premium when selected
What's intentionally excluded
- Skylight replacement (use a separate skylight calculator)
- Gutter and downspout replacement
- Solar panel removal and reinstall
- Structural repairs beyond decking-sheet replacement (truss work, ridge beam)
- Sales tax and financing interest
- Code upgrades beyond ordinary current-code install (separate line item in real bids)
Why prices vary so much
Two homes with identical floor plans on the same block can legitimately get bids 30–40% apart. The big drivers, in order: access (steep pitch + 2-stories + tight lot raises labor), decking surprise (older homes or any prior leak history), complexity (dormers, valleys, multiple gables stack up), material grade within a category (architectural shingles span $130–$185 per square), and contractor overhead (a roofer with proper insurance, workers' comp, and a real warranty program costs more than a one-truck operation — and is worth it).
Why we still ask you to get contractor quotes
A precise number requires three things this calculator cannot provide:
- A measurement of your specific roof (drone or hand-measured)
- A decking inspection (often only possible during tear-off)
- Current local material availability (lead times move pricing)
Use this calculator to know what range to expect, then collect three real quotes and compare them line-by-line. That's the workflow that produces the right roof at the right price.
Editorial independence
Cost data is set by Eurocraft (Texas-licensed general contractor, Houston-area). Eurocraft does not solicit business through Kefiw and does not take payment for content placement. See about for editorial-policy and conflict-of-interest disclosure.