The cost of roofing replacement depends on six things homeowners need to know before comparing quotes: the roof’s size in squares, the material chosen, how many old layers come off, how much deck needs repair, the flashing and ventilation work, and code upgrades the replacement itself can trigger, such as cool-roof or Class A fire requirements. Two quotes for the same house can differ widely because they price different scopes, not because one roofer is cheaper. This guide explains each driver so you can compare like with like; it shows no prices, because installed prices change with material costs and every roof differs. For a written estimate, call NEMA Roofing at 866-631-3366.
What goes into a roof replacement quote?
| Line item | What it covers | Why it varies |
|---|---|---|
| Roof size | Measured in squares (100 square feet of roof surface) | Pitch adds surface area beyond the house footprint; hips, valleys and dormers add waste |
| Tear-off and disposal | Removing the old covering and underlayment to the deck | Number of layers; heavy tile takes more labor and disposal |
| Deck repair | Replacing rotted or damaged sheathing | Unknown until tear-off, so it should be a unit price |
| Underlayment | The water barrier under the covering | Type and brand, often set by the manufacturer’s system |
| Roof covering | Shingles, tile, metal or a membrane | Material, product line and color |
| Flashing | Walls, chimneys, skylights, vents, valleys | New flashing vs reused; number of penetrations |
| Ventilation | Intake and exhaust vents | Whether the attic needs correcting |
| Permit and code items | Building permit; code-required upgrades | Cool-roof values, fire rating, local rules |
Which choices change the cost the most?
- Material. Asphalt shingles are the most common covering; State Farm’s homeowner guide describes metal as more expensive than shingles up front, and tile adds weight and labor. A 2007 National Association of Home Builders survey put asphalt shingles at about 20 years of expected life and clay or concrete tile at over 50, which is why many owners weigh up-front cost against how long the roof should last.
- Steepness and height. Steep and two-story roofs need more safety equipment and slower work.
- Complexity. Every valley, hip, dormer, chimney and skylight adds cutting and flashing.
- Existing layers. More layers mean more tear-off; heavy tile is the most labor-intensive to remove.
Which rules can add to a replacement?
- Cool roof requirements. In California’s inland climate zones (for example Woodland Hills, Tarzana and most of Thousand Oaks, zone 9), replacing more than half of a steep-slope roof requires rated cool-roof values unless an exception applies. On flat and low-slope roofs the requirement reaches the coast too (zones 4 and 6 through 15), including Santa Barbara and Ventura.
- Fire rating. Where the 2025 California Wildland-Urban Interface Code applies (Fire Hazard Severity Zones and wildland-urban interface areas), a roof covering that is replaced, or has 50 percent or more replaced within 12 months, must meet the Class A rating required for new construction.
- Permits. A replacement needs a building permit from the city or county; the permit is also where these rules are checked.
How do you compare two quotes fairly?
- Check both quote the same number of squares and the same number of layers to remove.
- Compare the named product line, underlayment and flashing, item by item.
- Make sure deck repair is a stated unit price in both.
- Confirm who pulls the permit and that code items (cool roof, Class A) are included.
- Check the warranties: the manufacturer’s coverage and the contractor’s workmanship coverage.
- Check the license on the Contractors State License Board site; NEMA Roofing holds CSLB license #1083283. California caps a home improvement down payment at 10 percent of the price or a fixed dollar limit, whichever is less.
Can you lower the cost without cutting corners?
- Replace before leaks damage the deck, which keeps deck repair small.
- Choose a product and color that already meet your zone’s cool-roof values, so no trade-off work is needed.
- Ask whether financing or phasing related work (gutters, insulation) together saves a second mobilization.
For the measuring method, see the roof replacement cost calculator guide; for paying over time, roof replacement financing options; and for local detail, roof replacement cost and pricing in Tarzana. NEMA Roofing replaces roofs from five locations (Santa Barbara, Oxnard, Tarzana, Woodland Hills and Downey) across Santa Barbara, Ventura, Los Angeles, Riverside and San Bernardino counties; see our roof replacement service. For a written estimate built from your roof, call NEMA Roofing at 866-631-3366.
