Willistown has 4,559 homes, and half of them were standing by 1979. Below: what the code asks of a replacement here, the permit, and the town’s own records.
New Roofing Costs connects homeowners with independent local roofing contractors. We do not perform roofing work.
This number connects homeowners who are planning a new roof or a full roof replacement with independent local roofing contractors. It is not for leak repairs or patch jobs. The call must come from the homeowner who decides on the roof. Calls may be recorded.
Permit
Pennsylvania’s code leaves residential alterations without structural change to local ordinance (34 Pa. Code § 403.1(b)(8)). Whether Willistown wants a permit is in its own ordinance; ask the township code office before the old roof comes off.
Source: 34 Pa. Code § 403.1(b)
Layers
On a roof that already carries two layers, or slate or tile, the code allows no recover: it is a tear-off (IRC R908.3.1.1). 51% of Willistown’s homes were built before 1980; many have been reroofed before.
Ice barrier
Whether an eave membrane is a code item depends on the climate table the municipality filled in when it adopted the code (IRC R905.1.2, Table R301.2). The contractor or the township code office in Willistown will know.
Rules as read on October 24, 2026. The state’s code edition and the rest of its rules: roof replacement in Pennsylvania.
93% of the occupied homes in Willistown are lived in by their owners: 4,049 households, the people this line is for. By year built, 7% before 1940, 26% before 1960, 51% before 1980; 18% went up in 2000 or later. (ACS 2020–2024.)
By building type: 71% detached houses, 26% attached single-family houses (rowhouses, twins and townhouses).
Of the 71 Chester County municipalities on this site, Willistown has the 22nd largest share of homes built before 1980: 51%, against a county range of 12% to 80%.
ZIP codes: 19073 · 19301 · 19355
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Willistown | 1979 | 51% | 93% | 26% | 14 |
| Malvern | 1974 | 65% | 56% | 24% | 16 |
| East Goshen | 1982 | 46% | 72% | 25% | 13 |
| Easttown | 1968 | 65% | 88% | 11% | 14 |
| Edgmont | 1991 | 20% | 78% | 22% | 14 |
| East Whiteland | 1993 | 37% | 60% | 18% | 18 |
Median built: median year the homes were built. Before 1980: share of homes built then. Owners: share of homes that are owner-occupied. Row, twin: share of homes that are rowhouses, twins or townhouses. Census ACS 2020–2024. Hail days: days with hail of 1 inch or larger within 10 miles, 2006–2025, NOAA Storm Prediction Center.
Since 2006 the National Weather Service has logged hail of 1 inch or larger on 14 separate days within 10 miles of Willistown; the largest was 2 in on August 10, 2008. The most recent was June 6, 2023.
Remnants of Hurricane Ida (DR-4618, September 2021) is the latest of 5 federal storm declarations covering Chester County since 2006. (OpenFEMA.)
A report says hail fell near Willistown, not that it damaged a roof. When wind or hail damage means a new roof.
Lifespans come from HUD’s capital-needs table, not from a brochure. More in the guides to shingles, metal, slate and flat roofs.
| Material | HUD useful life | Fits a house like | Watch for |
|---|---|---|---|
| Asphalt shingles | 20 years | Most pitched roofs; 71% of homes here are detached | Wind class set by the design wind speed (IRC Table R905.2.4.1) |
| Metal (standing seam, panels) | 50 years | Low pitches and long runs | Standing seam that carries its own loads can skip the tear-off (R908.3.1) |
| Slate | 75 years | Older houses; 7% here predate 1940 | Can’t be roofed over; check the framing for the weight |
| Flat roof: EPDM or TPO | 15 years | Low-slope roofs and rear sections (26% of homes here are attached) | Where the roof meets a wall or parapet |
Pennsylvania’s home improvement law (HICPA § 3, § 6) requires registration with the Attorney General from $5,000 a year of such work and puts the number on every estimate; ask for it in Willistown and look it up.
The price side is in what a new roof costs in Pennsylvania; the paperwork side in checking a roofing contractor.
Willistown’s ordinance decides. Pennsylvania’s code leaves residential alterations without structural change to local ordinance (34 Pa. Code § 403.1(b)(8)). Whether Willistown wants a permit is in its own ordinance; ask the township code office before the old roof comes off.
On a roof that already carries two layers, or slate or tile, the code allows no recover: it is a tear-off (IRC R908.3.1.1). 51% of Willistown’s homes were built before 1980; many have been reroofed before.
By the Census Bureau’s American Community Survey (2020–2024), the median home in Willistown was built in 1979, 51% of homes were built before 1980, 93% are owner-occupied.
Hail of 1 inch or larger was reported on 14 days within 10 miles of Willistown from 2006 through 2025 (NOAA Storm Prediction Center). A report means hail fell nearby, not that a roof was damaged.
Pennsylvania’s home improvement law (HICPA § 3, § 6) requires registration with the Attorney General from $5,000 a year of such work and puts the number on every estimate; ask for it in Willistown and look it up.
The full list: before you call.
Checked October 24, 2026. Laws and code editions change; the date says when these were last read at the source.