How a replacement gets measured
Roofers price by the square, which is 100 square feet of roof surface, not by the floor area of the house. A home's roof area is larger than its footprint because of pitch, overhangs and dormers, and a steep, cut-up roof can have far more surface than a simple gable on the same lot. Many contractors now use aerial or satellite measurement reports and then confirm on site.
Waste is part of the count. Hips, valleys and short runs mean more cut shingles, so a complex roof needs a higher waste allowance. Ask each roofer how many squares they measured and what waste factor they used; if two bids differ a lot on squares, one of them measured wrong.
Line items a complete estimate should show
Tear-off of the existing layers and disposal; the shingle product line and color; synthetic underlayment over the whole deck; ice-and-water membrane in valleys and around penetrations; new drip edge; starter strips; ridge vent or other exhaust ventilation; new pipe collars; step and counter flashing at walls and chimneys; and ridge caps. The estimate should also say whether existing flashing will be reused or replaced, since reusing old step flashing is a common shortcut.
Decking deserves its own line. Nobody can see rotten plywood until the shingles are off, so good estimates state a per-sheet price for any replacement decking rather than leaving it open-ended.
What makes Johns Creek reroofs cost more or less
Size and complexity lead. Many subdivisions off Medlock Bridge, State Bridge and Old Alabama Road were built with large two-story plans, multiple gables and steep 10/12 or 12/12 front slopes, which require extra safety setup and slower installation. Material choice comes next: architectural shingles are the common choice here, while impact-resistant shingles, standing-seam metal, slate or synthetic slate change the price substantially.
Other movers include a second layer that has to be torn off, skylights that should be reflashed or replaced, chimney crickets, and gutters. If your gutters are near the end of their life, replacing them during the reroof saves a separate setup; see gutters with a new roof.
City of Johns Creek permit rules for a reroof
Johns Creek issues its own building permits through the Community Development Department rather than Fulton County. The City's "Do I Need a Permit?" checklist says a roof replacement with no structural work and no more than 32 square feet of decking replaced does not need a building permit. Structural work, or more decking than that, does. When a permit is required, the City's fee schedule bases it on job valuation with a $175 minimum and a $50 administration fee, as shown in the table below. Work still has to meet the adopted residential code either way. How owners budget that roof replacement cost in Johns Creek, including insurance and payment terms, is a separate guide.
HOA approval before you sign
Many neighborhoods require architectural review of shingle color and profile before work starts. Get the approved color list first so each roofer quotes a product you can actually install. Our HOA architectural packet guide walks through what most review committees ask for.
Insurance-funded replacements
If a storm caused the damage, the insurer's adjuster writes a scope and the roofer's estimate should be compared against it line by line. Keep the claim and the contract separate in your mind: you choose the contractor, and you should not sign a replacement contract before you understand what the policy will pay.
Warranties, timing and payment
There are two warranties: the manufacturer's on the shingles and the contractor's on the workmanship. Ask how long the workmanship warranty runs and whether the installer is certified by the manufacturer for an enhanced warranty. Most single-family reroofs in the area finish in a few working days once materials arrive. Avoid paying the full price up front; a deposit for materials and the balance on completion is common.
City permit rules and fees
Short answer: the table below runs from $6.50 (Building permit, minor alteration of an existing structure) up to $50 (Administration fee, on all permits), according to City of Johns Creek fee schedule. These are published government figures; labor and materials for the job come from a written quote.
| Item | City rule or fee | Source |
|---|---|---|
| Roof replacement, no structural work (up to 32 sq ft of decking) | No building permit required | City of Johns Creek, Do I Need a Permit? |
| Roof work requiring structural alterations | Building permit required | City of Johns Creek, Do I Need a Permit? |
| Building permit, minor alteration of an existing structure | 30% × $6.50 per $1,000 of valuation; $175 minimum | City of Johns Creek fee schedule |
| Building permit, major alteration of an existing structure | 40% × $6.50 per $1,000 of valuation; $175 minimum | City of Johns Creek fee schedule |
| Administration fee, on all permits | $50 | City of Johns Creek fee schedule |
| Work done without a required permit | Double the total permit fees | City of Johns Creek fee schedule |
| Non-structural minor repairs costing under $2,500 | May be done without a permit, only with the Building Official's permission | City of Johns Creek, Do I Need a Permit? |
Sources: City of Johns Creek, Do I Need a Permit?; City of Johns Creek, Community Development Fee Schedule (PDF).
Local rules and code references
- City of Johns Creek, Do I Need a Permit?: roof replacement with no structural work (up to 32 square feet of decking) is listed as not needing a permit; new roofs requiring structural alterations do need one; non-structural minor repairs under $2,500 may proceed without a permit only with the Building Official's permission.
- City of Johns Creek Building Codes: the City enforces the Georgia State Minimum Codes, including the 2024 International Residential Code with Georgia amendments effective January 1, 2026.
- City of Johns Creek Building FAQs: permits must be obtained before work starts; working without a required permit can bring stop work orders and penalties; permitted work requires City inspections.
- Georgia DCA, State Minimum Standard Codes: Georgia's adopted construction codes and amendments that cities such as Johns Creek enforce.
Code text and department procedures change; confirm current requirements with the jurisdiction before work starts.