Replacing a roof in the Bay Area generally lands somewhere between $20,000 and $60,000, and the reason that range is so wide has less to do with your house than with your roof. Roof replacement cost is driven by roof area, material, and what the crew finds once the old covering comes off. Pricing jobs week after week across Los Gatos, San Jose, Cupertino, and Saratoga, our numbers tend to land near $1,000 per square for composition shingle, $1,400 to $1,600 for concrete tile, $1,600 to $1,800 for clay, and near $1,800 for standing seam metal.
Every figure below is an estimate drawn from our own field experience, not a quote. No honest price exists until somebody has physically walked the roof, measured it, and looked at the details.
What a Roofing Square Is, and Why Every Price Depends On It
A square is roofing’s unit of measure: a 10-foot by 10-foot area, or 100 square feet of roof surface. Contractors price by the square because it is the only measurement that tracks the actual work — material, labor, tear-off, and disposal all scale with roof area, not with bedrooms or bathrooms.
Roof area is also not the same thing as house area, and that difference surprises people. A roof overhangs the walls, usually by a foot or two on each side, and a pitched plane covers more surface than the flat footprint underneath it. Garages, porches, and patios also add to the roof area. And remember a 2-story house has twice the living area under the roof, thus less roof area than a one-story with the same house square footage. Once all factors are counted, a 2,000 square foot single-story home commonly measures out at more than 30 squares.
So when a neighbor tells you what they paid, the only way to compare is per square. Total price without square count is a number with no unit attached.
Roof Replacement Cost Per Square, by Material
Composition shingle: roughly $1,000 per square
Composition, also called asphalt shingle, is what goes on roughly 95 percent of the reroofs in this valley. There is a real range inside that $1,000 figure depending on how much plywood the deck needs, which shingle grade you choose, and whether gutters are part of the job. In this climate, a composition roof is a 25- to 30-year roof — no matter what the warranty on the wrapper says.
Tile: $1,400 to $1,600 per square for concrete, $1,600 to $1,800 for clay
Tile is two products at two prices, and an estimate that says only “tile” is hiding which one you are getting. Concrete is a manufactured commodity — sand, cement, and pigment, produced in volume — at $1,400 to $1,600 per square. Clay is dug, formed, and kiln-fired, closer to a custom order, at $1,600 to $1,800. The differences go well beyond price, and we lay them out in concrete tile vs clay tile.
An existing tile roof with sound plywood and a straightforward design can come in closer to $1,100 or $1,200 per square, because the flashings and details are already established and the crew is largely replacing the underlayment beneath the tile. Converting from composition or old wood shake over to tile roofing is a different job entirely, since every wall flashing, valley, and transition has to be built new for a thicker material.
Standing seam metal: roughly $1,800 per square
Standing seam runs close to double composition, and that figure carries a qualifier worth understanding. The $1,800 describes the metal system installed over a sound, prepared deck, which is essentially a new-construction price. A reroof adds tear-off and disposal of the existing covering, re-skimming, and plywood on top of that, and those are real line items rather than rounding.
On a cut-up roof with a lot of hips, valleys, and wall transitions, the installed number climbs toward $2,300 to $2,400 per square, because every one of those angles is fabricated flashing and hand labor. The tradeoff is service life, which we walk through in asphalt shingle vs standing seam metal: what does each actually cost?.
Synthetic and composite products: above metal
Polymer shake and slate lookalikes price higher than standing seam. The product itself is expensive, the piece count is high once you add hip, ridge, valley, and starter pieces, and freight is a real line item because these are specialty orders rather than something stocked locally at a supply house. Whether that premium is justified is its own question, covered in our synthetic roof shingles worth it?.
Taken together, most South Bay roofing prices out between $1,000 and $2,500 per square.
What a Whole Roof Costs on an Average Los Gatos or San Jose Home
The average Bay Area house works out to 20 to 30 squares of roof. Run the per-square numbers across that, and the picture gets concrete:
- Composition: roughly $20,000 to $30,000
- Concrete tile: roughly $28,000 to $48,000
- Clay tile: roughly $32,000 to $54,000
- Standing seam metal: roughly $36,000 to $54,000 for the metal system, and commonly $40,000 to $60,000 on a reroof once tear-off and decking are included
Those estimates assume a full tear-off, a deck in ordinary condition, and a roof design typical of postwar South Bay construction. A steep, heavily articulated roof in Los Altos Hills and a simple gable in Willow Glen will not price the same way even at identical square counts.
Why Your Neighbor Paid Less for a House the Same Size
A few years back, two Cupertino neighbors compared invoices and one of them called us, convinced something was wrong. Both homes were about the same square footage. One paid noticeably less than the other, and the homeowner who paid more wanted to know why.
The answer was that the two houses did not have the same amount of roof. One was a large single-story home, the other a two-story with the same living space. Stack the same square footage onto two floors, and you cut the footprint roughly in half, and the roof follows the footprint.
A 2,500 square foot two-story house has roughly half the roof of a 2,500 square foot single-story house. This is the single most useful thing a homeowner can understand before comparing prices: roof replacement is sold by roof area, and single-story homes carry far more of it. Nobody was overcharged. One house simply had twice the roof.
The Six Things That Actually Move the Price
- Size. Total roof area in squares. Everything else is a modifier on this number.
- Material. Composition: tile, metal, or synthetic — a spread of better than two to one from one end to the other.
- What is already up there. Two layers to remove instead of one, delaminating plywood, dry rot at the eave. Deck condition is invisible until tear-off day, which is exactly why it belongs in the conversation before the job starts.
- Detail and complexity. Hips, valleys, chimneys, skylights, and roof-to-wall transitions. Flashing is the sheet metal that seals those transitions; it is fabricated and installed by hand, and it is also where roofs actually leak.
- Pitch. Past a certain steepness, fall protection stops being optional. Cal/OSHA’s residential fall protection rules changed as of July 1, 2025, and now trigger at six feet on ordinary slopes, with roofs steeper than 7:12 requiring fall protection at any height. Rigging that costs time and money every single day of the job.
- Access. Where the truck parks, how far material has to travel, whether there are mature oaks over the driveway, whether the crew can stage on site or has to carry everything around the house.
What a Free Roof Estimate Should Actually Show You
Free roof estimates are common in this trade, which makes the comparison between them the homeowner’s real job. A useful estimate names the square count, the material and grade, whether plywood is included and at what price per sheet, how many layers are being removed, and what happens to the price if the deck turns out to be worse than it looks.
The pattern to watch for is the bid that starts at $20,000, becomes $23,000 on day one when a second layer of roofing appears, then $28,000 when the plywood nobody mentioned goes on. The bid that looked $3,000 higher often included all of it from the start. Once the roof is off, you cannot say stop.
Ask for the square count. Ask what is excluded. A contractor who has measured your roof and priced its details can answer both without hedging, and the answers are what let you compare two proposals honestly.
If you are trying to budget a reroof and want real numbers for your own roof rather than a range, having someone measure it and walk the details costs nothing and takes about an hour. Our family has been doing that math for South Bay homeowners since 1978, and a free estimate is information you get to keep whether or not you hire us.