The Borough of Mars, in Butler County, Pennsylvania, has its own zoning ordinance, and building work inside the borough needs a building permit under the Uniform Construction Code the borough adopted123. A zoning review fee and an occupancy permit apply too4. We could not confirm who issues septic permits inside Mars, so ask the borough office before you buy.
At a glance
- Building permit
- Required for listed construction, depending on size and type3
- Building code
- Pennsylvania Uniform Construction Code, adopted by the borough2
- Zoning
- Borough zoning ordinance with R-1, R-2, R-3, R-4, commercial and industrial districts15
- R-1 minimum lot
- 10,000 square feet6
- Occupancy permit
- Required at completion; listed fee $257
- Septic
- State requires a local-agency permit; Mars borough's agency not confirmed8
Who to call
Building permits
Borough of Mars office and Zoning Officer
Zoning review, building permits and occupancy permits inside Mars borough; permit forms are submitted to the borough office, the Zoning Officer or appointed inspection agencies
Contact details are copied from each office’s official page and were checked against it on October 24, 2026.
Off-grid gear
Going off-grid in Borough of Mars means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.
Does Mars, PA have zoning, and what does it mean for lot size and height?
Yes. The Borough of Mars adopted its own zoning chapter, and it covers land inside the borough1. The zoning chapter names R-1 Single-Family, R-2 Single- and Two-Family and R-3 Multifamily residential districts, along with commercial and industrial districts5.
In the R-1 and R-4 districts, the minimum lot size is 10,000 square feet6. Buildings may cover at most 25% of an R-1 lot9, and the height limit is 35 feet, with exceptions for the structures named in the code's notes10.
We could not confirm the borough's rules on RV living, tiny homes, accessory dwellings or manufactured homes, so ask the Zoning Officer before you plan any of them5.
Do you need a building permit in Mars, and who issues it?
Yes, for the construction the borough's fee chapter lists. Building work in the Borough of Mars requires, depending on size and characteristics, a zoning review fee, a building permit fee and an inspection fee3. The borough adopted Pennsylvania's Uniform Construction Code as its municipal building code2.
Permit forms go to the Borough office, the Zoning Officer or the appointed inspection agencies11. The borough lists a zoning review fee of $50 for building permits required by the UCC and for structures over 64 square feet4. Building permit and inspection fees follow the current UCC third-party inspector schedule, and inspections not done by a borough-appointed representative are billed to the owner4.
Pennsylvania law lets an owner be the named permit applicant12. We could not confirm a separate owner-builder rule inside Mars, so ask the borough office.
How do septic permits work inside Mars?
We could not confirm who issues septic permits inside the Borough of Mars, because the borough code we reviewed does not say. Pennsylvania requires a permit from the local agency before installing or using an onlot sewage system8. The local agency can be a municipality, a group of municipalities or a county health department13.
If the lot connects to public sewer, no onlot system applies, but we could not confirm sewer service for any particular address. Ask the Borough of Mars office whether the parcel is sewered and, if not, which local agency issues the septic permit. The state also lets a homeowner who drills their own private well skip the driller licence14; we found no Mars well rule.
Building a home in Mars: the steps, in order
- Ask the Borough of Mars Zoning Officer which zoning district the parcel is in and what lot size, coverage and height limits apply5.
- Ask the borough office whether the lot has public sewer or needs an onlot septic permit8.
- Apply for the building permit and pay the zoning review and inspection fees3.
- If the driveway meets a state road, get a PennDOT Highway Occupancy Permit first15.
- Schedule the required inspections as work proceeds16.
- Get the occupancy permit at completion; the borough lists a $25 fee7.
What stays with Butler County, and what to check before you buy
Subdivision and land development inside Mars is regulated, and the borough's code says the Butler County ordinance is currently enforced in the borough17. Splitting a lot therefore starts with the county planning office, which does not run zoning or building permits for the borough. For land outside the borough, see the Butler County page.
County figures: Butler County's effective property tax rate is 1.1%18. The share of county soils rated not limited for a conventional septic drain field is 1.1%, so expect a site evaluation or an engineered system on an unsewered lot19. Building in a floodplain requires documentation sealed by a registered design professional20.
Watch-outs
Sources
- Chapter 270: Zoning - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Chapter 107: Construction Codes, Uniform - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Chapter 126: Fees - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Chapter 126: Fees - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Chapter 270: Zoning - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Article VI: Dimensional Requirements - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Chapter 126: Fees - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- 25 Pa. Code § 72.22. Permit issuance (Pennsylvania statewide rule), quoted and re-checked
- Article VI: Dimensional Requirements - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Article VI: Dimensional Requirements - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Borough of Mars office and Zoning Officer (ecode360.com)
- Apply for a Uniform Construction Code Building Permit | Commonwealth of Pennsylvania, quoted and re-checked
- Act 537 Sewage Facilities (Pennsylvania statewide rule), quoted and re-checked
- Apply for a Water Well Drillers License and Rig Permit (Pennsylvania statewide rule), quoted and re-checked
- Apply for a PennDOT Highway Occupancy Permit, quoted and re-checked
- Pennsylvania Uniform Construction Code, Chapter 403, quoted and re-checked
- Chapter 230: Subdivision and Land Development - Borough of Mars, PA (Borough of Mars), quoted and re-checked
- Effective property tax rate: Bolthole Index county data
- 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
- Apply for a Uniform Construction Code Building Permit, quoted and re-checked
Written October 24, 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.