Bolthole Index

Chester County, Pennsylvania

Zoning, building permits and septic rules in Tredyffrin Township, Pennsylvania

Tredyffrin Township, in Chester County, Pennsylvania, has its own zoning (Chapter 208)1 and enforces the Uniform Construction Code through its own inspections department2. Building permits are required for residential construction3. Septic permits and well permits come from the Chester County Health Department, not the township4.

At a glance

Building permit
Required; the township's inspections department enforces the Uniform Construction Code23
Zoning
Township zoning, Chapter 208, with districts such as R-1 and RC1
Septic permit
Chester County Health Department4
RV living
Not allowed as living space; one RV may be stored in the RC district5
Minimum home size
900 sq ft one-story, 1,200 sq ft two-story6
Minimum lot
30,000 sq ft in R-1; 5 acres in RC78
Owner-builder
No general contractor license needed for work on your own residence9

Who to call

Building permits

Tredyffrin Township Inspections Department

Building permits and inspections under the Uniform Construction Code inside Tredyffrin Township

Septic permits

Chester County Health Department

Septic (on-lot sewage) permits and well permits for addresses in Chester County, including Tredyffrin Township

610-344-6225

601 Westtown Road, Suite 295

Contact details are copied from each office’s official page and were checked against it on October 14, 2026.

Off-grid gear

Going off-grid in Tredyffrin Township means bringing your own water and power. The kit we’d start with:

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Does Tredyffrin Township have zoning, and what does it mean for lot size and setbacks?

Tredyffrin Township, Pennsylvania administers its own zoning through Chapter 208 of the township code, organized into district articles such as R-1 and RC1. Dimensions depend on the district, so check the zoning map for your parcel first.

In the R-1 Residence District, a dwelling lot needs at least 30,000 square feet and 100 feet of width at the building line7. Required yards are 40 feet in front, 25 feet in the rear, and 40 feet of side yards in total with neither under 15 feet10. Buildings may cover 20% of the lot and impervious surface 30%11.

In the RC Rural-Conservation District, the minimum is five acres and 300 feet of width8. Front yards must be at least 100 feet, rear yards 50 feet, and side yards 100 feet in total with neither under 45 feet12. Buildings may cover only 5% of the lot and impervious surface 10%13. Building height is limited to 35 feet in R-1, and the same limit applies in RC14.

Do you need a building permit in Tredyffrin Township, and who issues it?

Yes. Pennsylvania's Uniform Construction Code requires building permits for residential buildings and the regulated electrical, mechanical and plumbing work in them3. Tredyffrin Township elected to administer and enforce that code itself, and its inspections department does the work215.

The township's fees are set by resolution of the Board of Supervisors, and fees are not pro-rated or partially refunded16. We could not confirm the current fee amounts, the permit application steps or a certificate-of-occupancy procedure, so ask the Tredyffrin Township inspections department before you apply.

Township zoning approval is a separate step from the building permit1.

How do septic permits work in Tredyffrin Township?

Septic permits for Tredyffrin Township addresses come from the Chester County Health Department, which issues permits for individual and small-community on-lot sewage systems and for well construction417. A permit is required for new systems, repairs and modifications18. The application needs at least one acceptable percolation test and at least two acceptable test pits18.

A well permit is also required before installing or altering a well19. Whether a given lot is on public sewer is a township question we could not confirm, so ask the township before assuming you need an on-lot system.

Across Chester County, about 24% of soils are rated not limited for a conventional drain field, so many lots need a site evaluation20.

Can you live in an RV or tiny home in Tredyffrin Township?

Not in an RV. In the RC district, the township allows parking or storing one recreational or commercial vehicle, up to 26 feet long, but it may not be used for living or housekeeping5. The vehicle also cannot sit in the required front yard, and a side or rear yard location needs screening5.

We could not confirm a township rule on tiny homes or temporary camping, so ask the township zoning office before planning either. Any permanent dwelling must meet the minimum floor area: 900 square feet for a one-story single-family home and 1,200 square feet for a two-story home, not counting porches and garages6.

Short-term rentals in Tredyffrin Township

In the R-1 district, a short-term rental is allowed only in a historic structure and only by special exception21. The township also has a separate property-registration chapter for short-term rentals that we have not confirmed in detail21.

Building a home in Tredyffrin Township: the steps, in order

  1. Find your district (R-1, RC or another) on the township zoning map and check lot area, setbacks and coverage1.
  2. Confirm septic or sewer. Septic permits and well permits go through the Chester County Health Department419.
  3. Apply for the building permit with the township inspections department2.
  4. Schedule inspections as construction proceeds; the township's code official is the township manager or designee15.
  5. Ask about a driveway onto a state road: PennDOT requires a highway occupancy permit for driveways connected to state highways22.

What stays with Chester County, and what to check before you buy

Chester County, not the township, handles septic permits and well permits4. The county planning commission supports municipal planning but does not administer township zoning or building permits23. For land outside Tredyffrin, see the Chester County page.

County figures for context: the effective property tax rate is 1.3%24, and the median property tax bill is $6,191 a year25. Pennsylvania lets an owner build on their own residence without a general contractor license9. If any part of the lot lies in a flood hazard area, development there requires a permit26.

Watch-outs

  • Tredyffrin Township's own website did not allow automated access, so we could not confirm a township phone number or the current permit fee schedule; the fees are set by resolution, so ask the inspections department16.
  • Within the township's historic district, the building code official must also coordinate with the Board of Historical Architectural Review before a permit is granted15.
  • Zoning is set by the township, not Chester County, so the county's planning staff cannot grant zoning approval for a Tredyffrin lot1.

Sources

  1. Township of Tredyffrin, PA code table of contents (eCode360) (Tredyffrin Township), quoted and re-checked
  2. Chapter 80 Building Construction - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  3. Part XIV, Uniform Construction Code, Chapter 403 Administration (Pennsylvania statewide rule), quoted and re-checked
  4. Sewage & Water, quoted and re-checked
  5. Article IV: RC Rural-Conservation Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  6. Article XXIV: General Provisions - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  7. Article VII: R-1 Residence Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  8. Article IV: RC Rural-Conservation Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  9. Contractor Licensing (2026 county census)
  10. Article VII: R-1 Residence Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  11. Article VII: R-1 Residence Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  12. Article IV: RC Rural-Conservation Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  13. Article IV: RC Rural-Conservation Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  14. Article VII: R-1 Residence Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  15. Tredyffrin Township Inspections Department (ecode360.com)
  16. Chapter 80 Building Construction - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  17. Chester County Health Department (chesco.org)
  18. Permits for On-Lot Sewage Disposal Systems, quoted and re-checked
  19. Chester County Health Department Rules and Regulations, quoted and re-checked
  20. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  21. Article VII: R-1 Residence Districts - Township of Tredyffrin, PA (eCode360) (Tredyffrin Township), quoted and re-checked
  22. Apply for a PennDOT Highway Occupancy Permit (Pennsylvania statewide rule), quoted and re-checked
  23. Chester County PA - Planning Commission (2026 county census)
  24. Effective property tax rate: Bolthole Index county data
  25. Median property tax bill: Bolthole Index county data
  26. PennsylvaniA Floodplain Development Guide (Pennsylvania statewide rule), quoted and re-checked

Written October 14, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Tredyffrin Township

Tredyffrin Township’s own rules

  • Building code adoptedAdopted

    Construction inside Tredyffrin township

    • Township amendments listed in § 80-2 reference the 2018 IBC and 2018 IPC (amended 4-18-2022 by Ord. HR-450).
    • Board of appeals established by resolution (§ 80-5).
    “the uniform construction code, contained in 34 pa. code, chapters 401-405, as amended, is hereby adopted and incorporated herein by reference as the construction code of the township of tredyffrin.”
  • Local zoningPresent

    Land inside Tredyffrin township

    • Zoning is administered through Chapter 208 with district articles such as R-1 and RC.
    “a lot area of not less than 30,000 square feet and a lot width of not less than 100 feet at the building line shall be provided.”
  • Minimum dwelling sizeSpecified

    Single-family dwellings inside Tredyffrin township (Article XXIV general provisions, all districts)

    • Exclusive of porch and garage areas

    minimum floor area, one-story: >= 900 sq ft · minimum floor area, two-story: >= 1200 sq ft

    “no one-story single-family dwelling erected on any lot shall have a floor area of less than 900 square feet, and no two-story single-family dwelling erected on any lot shall have a floor area of less than 1,200 square feet, exclusive of all porch areas (whether enclosed or not) and garage areas.”
  • Minimum lot sizeSpecified

    Dwelling lots in the R-1 Residence District inside Tredyffrin township

    • Nondwelling uses require 80,000 sq ft and 200 ft width (§ 208-23)

    lot area: >= 30000 sq ft · lot width at building line: >= 100 feet

    “a lot area of not less than 30,000 square feet and a lot width of not less than 100 feet at the building line shall be provided.”
    One more reviewed finding on this topic
  • SetbacksSpecified

    Dwelling lots in the R-1 Residence District inside Tredyffrin township

    front yard: >= 40 feet · side yards aggregate: >= 40 feet (neither less than 15 feet) · rear yard: >= 25 feet

    “d. front yard. there shall be a front yard on each street on which the lot abuts, the depth of which shall be at least 40 feet. e. side yards. there shall be two side yards not less than 40 feet in aggregate width and neither less than 15 feet in width. f. rear yard. there shall be a rear yard, the depth of which shall be at least 25 feet.”
    One more reviewed finding on this topic
    • Specified — Lots in the RC Rural-Conservation District inside Tredyffrin township
      “d. front yard. there shall be a front yard on each street on which the lot abuts, the depth of which shall be at least 100 feet. e. side yards. there shall be two side yards not less than 100 feet in aggregate width and neither less than 45 feet in width. f. rear yard. there shall be a rear yard, the depth of which shall be at least 50 feet.”
  • Lot coverageSpecified

    Dwelling lots in the R-1 Residence District inside Tredyffrin township

    building coverage: <= 20 percent · impervious coverage: <= 30 percent

    “b. building coverage. not more than 20% of the lot area may be occupied by buildings. c. impervious coverage. not more than 30% of the lot area may be covered by impervious surface.”
    One more reviewed finding on this topic
  • Building heightSpecified

    Buildings in the R-1 Residence District (dwellings) inside Tredyffrin township; same 35 ft limit in the RC district

    maximum building height: <= 35 feet

    “g. height. the height of any building shall not exceed 35 feet.”
  • Living in an RVLimited

    Parking/storage of recreational vehicles as accessory use in the RC Rural-Conservation District inside Tredyffrin township

    • Not more than one recreational or commercial vehicle
    • Vehicle not exceeding 26 feet in length
    • Not stored in required front yard or in front of the facade
    • Screening required in side or rear yard

    maximum vehicle length: <= 26 feet

    “(6) the parking or storage (outside of a garage) of not more than one recreational or commercial vehicle, including but not limited to motor homes, campers, boats and trailers, subject to the following conditions: (a) such vehicle shall not be used for living or housekeeping purposes. (b) such vehicle shall not exceed 26 feet in length, exclusive of its trailer hitch or towbar.”
  • Short-term rentalsLimited

    Short-term rentals in the R-1 Residence District inside Tredyffrin township

    • Only in a historic structure, by special exception, subject to § 208-122.1a
    • Township also has Chapter 150, property registration for short-term rentals (not opened)
    “(7) short-term rentals located in a historic structure, subject to the provisions of § 208-122.1a. [added 12-5-2022 by ord. no. hr-459]”
  • Permit feesVariable (with conditions)

    Construction code permit fees inside Tredyffrin township

    • Fee amounts are in a resolution not opened; fees are not pro-rated or partially refunded.
    “the board of supervisors shall establish by resolution fees for the administration and enforcement of the uniform construction code and this chapter. fees shall be refunded in full only if paid or collected erroneously. fees will not be pro-rated or partially refunded for any reason.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Tredyffrin Township or Chester County directly.

  • Building permit — Building permits inside Tredyffrin township
  • Owner-builder exemption — Owner-builder exemptions inside Tredyffrin township
  • Inspections — Building inspections inside Tredyffrin township
  • Certificate of occupancy — Certificates of occupancy inside Tredyffrin township
  • Zoning districts — Zoning districts inside Tredyffrin township
14 more unanswered
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Permit process

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Tredyffrin Township publishes no rule on the point, not that none exists. Chester County’s page lists the county offices to call.

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