How does the estimator work?
The math is geometry, not pricing. Footprint is living area divided by stories, plus an attached garage under the same roof. A pitch factor converts footprint to sloped surface: a 6-in-12 roof has about 12% more surface than a flat one, a 12-in-12 roof about 41% more. We then add 5% to 20% for overhangs. Divide by 100 and you have roofing squares.
What do typical San Mateo County homes come to?
These examples use the same geometry. They describe roof area only, not price.
| Example home | Footprint under the roof | Pitch | Roofing squares (approx.) |
|---|---|---|---|
| Daly City or South San Francisco tract home, 1,300 sq ft over a garage | about 650 sq ft | 4-in-12 pitch | 7 to 8 |
| San Mateo Highlands mid-century home, 1,900 sq ft, one story | about 1,900 sq ft | flat or nearly flat | 20 to 23 |
| Burlingame or San Carlos two-story, 2,600 sq ft | about 1,600 sq ft | 8-in-12 pitch | 20 to 23 |
What makes a roof in San Mateo County cost more than its size suggests?
The Peninsula's housing came mostly in the 1950s and 60s, and the roofs fall into a few families. Daly City and South San Francisco tracts are compact, low-pitch homes over garages, so they go fast. Mid-century homes in the San Mateo Highlands and similar hillside neighborhoods often have nearly flat roofs that need membranes. Larger two-story homes in Burlingame, San Carlos and Belmont add hips, dormers and steeper pitches. Fog on the west side of the hills keeps roofs damp, which shows up as rotten sheathing at tear-off.
What price range should I expect?
A broad frame is all a published source supports: the Cost vs. Value report places a typical full asphalt reroof in the tens of thousands of dollars and metal noticeably higher. Two homes with the same square count can still be priced far apart. For your actual price, request a free written estimate: a licensed roofer measures the roof and prices your exact scope.
What should I have ready for an estimate?
- Rough square footage and stories
- The year of the last reroof, if you know it
- Solar, skylights, chimneys or flat sections
- Any insurer letter about the roof
Related: what drives roof replacement cost, metal roofs, dry rot and decking, solar removal and reinstall and our quote checker.
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Get a free replacement quoteFrequently asked questions
How do I convert my house size to roofing squares?
Divide living area by stories, add a garage under the same roof, multiply by a pitch factor such as 1.12 for a 6-in-12 roof, add 5% to 20% for overhangs, then divide by 100.
Why won't you give a dollar range per home size?
Because two roofs of the same size can differ by many thousands of dollars. A written estimate after an inspection is the reliable number, and it's free.
Is a Daly City tract roof cheaper than a Burlingame two-story?
Usually, because a compact, low-pitch roof is fewer squares and less complex. Size and shape matter more than the city name.
Sources
Sources reviewed November 12, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.