Do I need a permit to build a deck in Allentown, PA?

Yes. In Allentown, any deck that is attached to the house or stands more than 30 inches above grade requires a building permit under the Pennsylvania Uniform Construction Code. You will need to submit a site plan showing the deck's dimensions, its distance from all property lines, and how it connects to the existing structure. The Bureau of Building Standards and Safety at City Hall reviews these applications. Permit fees are based on the estimated construction value of the project. Plan to allow two to four weeks for review on a straightforward deck permit. If your property is in a historic overlay district such as West Park, you may also need approval from the Historic and Architectural Review Board before the building permit is issued.

What are the setback requirements for a shed in Allentown?

In most Allentown residential zoning districts, accessory structures like sheds must be set back at least five feet from the rear property line and five feet from the side property line. Sheds are generally not permitted in the front yard. If your property is on a corner lot, additional setbacks from the street-side property line may apply. Sheds smaller than 200 square feet may not require a full building permit, but they still need to comply with zoning setback rules and may require a zoning permit. Sheds with electrical wiring or plumbing always require a building permit regardless of size. Confirm requirements for your specific parcel with the Allentown Bureau of Zoning before you begin construction.

How long does it take to get a building permit approved in Allentown, PA?

For most straightforward residential projects in Allentown, plan review takes approximately two to four weeks from the date a complete application is submitted. Projects that are incomplete, missing required documents, or located in special overlay zones such as the floodplain or a historic district can take considerably longer. Projects requiring Historic and Architectural Review Board (HARB) approval must complete that process before a building permit can be issued, which can add several weeks. To avoid delays, make sure your site plan is drawn to scale, includes all required setback dimensions, shows impervious surface calculations, and is accompanied by complete contractor documentation. Submitting a thorough application the first time is the best way to stay on schedule.

What does Allentown require on a residential site plan?

Allentown's Bureau of Building Standards and Safety expects a residential site plan to include: the legal dimensions of the lot and all property lines, the footprint and location of the existing house and any existing accessory structures, the proposed new construction drawn to scale with dimensions, the distances from all proposed structures to each property line (setbacks), the location of the driveway and any impervious surfaces with a coverage calculation, a north arrow, a graphic scale bar, and the property address. For projects near floodplains, a FEMA flood zone designation and, if required, an elevation certificate must accompany the plan. Properties in historic districts may need additional detail showing exterior materials and design elements for HARB review.

Can I draw my own site plan in Allentown, or do I need a licensed surveyor?

Pennsylvania law and Allentown's permit requirements do not always mandate a licensed surveyor or engineer for a basic residential site plan on simple projects like sheds, decks, or fences. Many homeowners and contractors prepare their own site plans using online tools such as Site Plan Creator, provided the drawing is accurate, drawn to scale, and includes all required elements. However, if your project involves structural engineering (such as a large addition or a pool with complex grading), if your property boundaries are disputed, or if you are in a floodplain requiring an elevation certificate, you will likely need a licensed professional. When in doubt, contact the Allentown Bureau of Building Standards and Safety before submitting to confirm what level of professional certification your specific project requires.

How much does a building permit cost in Allentown, PA?

Allentown calculates building permit fees based on the estimated construction value of the proposed project. The fee schedule is tiered, so larger and more expensive projects pay higher fees. As a general reference, smaller projects like sheds or simple decks might carry permit fees in the range of a few hundred dollars, while larger additions or new accessory dwelling units can result in fees of several hundred to over a thousand dollars depending on construction value. There may also be separate zoning review fees, plan review fees, and inspection fees. Because the fee schedule can be updated, contact the Bureau of Building Standards and Safety at (610) 437-7579 or visit City Hall at 435 Hamilton Street to get the current fee schedule before budgeting your project.

What happens if I build without a permit in Allentown?

Building without a required permit in Allentown is a violation of the Pennsylvania Uniform Construction Code and the city's local ordinances. If discovered, the city can issue a stop-work order immediately halting all construction. You may be required to obtain a retroactive permit, which often means opening up finished work so inspectors can verify code compliance. Fines and penalties can accumulate daily until the violation is resolved. Unpermitted work can also create serious problems when you sell your home, as title searches and home inspections often uncover missing permits, which can delay or kill a sale. In some cases, unpermitted structures must be removed entirely. It is always less expensive and less stressful to pull the permit before you build.

Are ADUs or garage conversions allowed in Allentown, PA?

Accessory dwelling units, including basement apartments, garage conversions, and carriage house units, are permitted in some Allentown residential zoning districts but are subject to specific regulations. The zoning district, lot size, parking availability, and owner-occupancy requirements all affect whether an ADU is allowed on a given property. Any ADU project requires a building permit, a zoning review, and a site plan demonstrating compliance with setbacks, lot coverage limits, and utility connections. Pennsylvania has been encouraging municipalities to allow more ADUs to address housing supply, so rules in Allentown may continue to evolve in 2026. Contact the Allentown Bureau of Zoning directly to confirm what is permitted for your specific parcel before investing in design or construction.

Does my Allentown property fall in a FEMA floodplain, and does that affect my permit?

Parts of Allentown along the Little Lehigh Creek, Jordan Creek, and their tributaries fall within FEMA-designated Special Flood Hazard Areas (SFHAs). If your property is in or near one of these zones, it can significantly affect your permit requirements. Projects in an SFHA may require a floodplain development permit in addition to the standard building permit, and you may need to provide an elevation certificate prepared by a licensed surveyor. New construction or substantial improvements in a floodplain must meet minimum finished floor elevation requirements. You can check your property's flood zone status using the FEMA Flood Map Service Center at msc.fema.gov. Allentown's floodplain administrator is located within the Bureau of Building Standards and Safety and can answer specific questions about your parcel.

Where do I submit a permit application in Allentown, PA?

Permit applications for residential projects in Allentown can be submitted in person at the Bureau of Building Standards and Safety, located at City Hall, 435 Hamilton Street, Allentown, PA 18101. As of 2026, the city also offers online permit initiation through its digital permitting portal for many project types, allowing you to upload your site plan and supporting documents electronically. For complex projects or those requiring HARB review, in-person submission and pre-application meetings with city staff are often advisable. The bureau can be reached by phone at (610) 437-7579. Staff can confirm whether your specific project type is eligible for online submission or requires an in-person visit and can provide the current permit application forms and fee schedule.

Site Plan Requirements in Allentown, PA (Permit Guide)

By Site Plan Creator Team • May 24, 2026

Allentown, PA homeowners must submit a residential site plan for most construction projects, from decks and fences to additions and ADUs. This guide covers Allentown's permit triggers, zoning setbacks, submission process, and how Site Plan Creator can help you get started quickly.

Site plan requirements for residential properties in Allentown, Pennsylvania

Residential Site Plans and Permits in Allentown, PA

Allentown is Pennsylvania's third-largest city, a growing urban center in Lehigh County with a mix of historic rowhouses, mid-century neighborhoods, and newer suburban developments. Whether you own a classic twin home near West Park or a detached single-family property in the South Side, the City of Allentown Bureau of Building Standards and Safety requires a properly prepared site plan before most residential construction projects can begin. Understanding what triggers a permit, what your site plan must show, and how to navigate the local review process can save you significant time and money in 2026.

What Is a Residential Site Plan and Why Does Allentown Require One?

A residential site plan is a scaled, bird's-eye drawing of your property that shows the boundaries of your lot, the location of your existing home and structures, proposed new construction, setbacks from property lines, driveways, utilities, and any relevant natural features. Allentown requires site plans because the city must verify that proposed work complies with the Allentown Zoning Ordinance, the Pennsylvania Uniform Construction Code (PA UCC), and applicable floodplain or stormwater regulations before issuing a building permit.

The Allentown Bureau of Building Standards and Safety administers permit applications and plan reviews for residential projects. Pennsylvania's statewide construction code framework is governed by the Pennsylvania Department of Labor and Industry, which oversees the Uniform Construction Code adopted by municipalities across the commonwealth.

Which Residential Projects Require a Permit in Allentown?

Allentown follows the PA UCC and its own local ordinance to determine when a permit is required. The following projects almost always trigger a permit and require a site plan:

Decks and porches: Any attached or freestanding deck over 30 inches above grade requires a building permit and a site plan showing setbacks and footprint.
Sheds and accessory structures: Sheds larger than 200 square feet, or any shed with electrical or plumbing, require a permit. Smaller sheds may still need zoning approval.
Swimming pools: In-ground and above-ground pools with a water depth exceeding 24 inches require a permit, site plan, and proof of compliant fencing.
Fences: Fences exceeding six feet in height typically require a zoning permit. Front-yard fences are subject to height restrictions and must be shown on a site plan.
Home additions: Any addition to the building footprint, including sunrooms, mudrooms, or expanded living space, requires a full building permit and detailed site plan.
Accessory Dwelling Units (ADUs): Allentown has seen growing interest in garage conversions and basement ADUs. These projects require permits, zoning approval, and a site plan demonstrating compliance with density and setback rules.
Driveways and impervious surfaces: New driveways or significant expansions of paved areas may require a grading or stormwater permit, especially given Allentown's MS4 stormwater obligations.
Detached garages: New garages require a building permit and a site plan showing placement relative to property lines and the principal dwelling.

Allentown Zoning Districts and Local Considerations

Allentown's zoning map divides the city into residential districts including R-1 (Low-Density Residential), R-2 (Medium-Density Residential), R-3 (High-Density Residential), and several mixed-use and historic overlay districts. The district your property falls in directly affects what you can build and where.

A few local quirks worth knowing:

Historic districts: Portions of Allentown, particularly around the West Park Historic District, are subject to additional review by the city's Historic and Architectural Review Board (HARB). Any exterior work visible from a public right-of-way may need HARB approval before a building permit is issued.
Floodplain overlay: Parts of Allentown along the Little Lehigh Creek and Jordan Creek corridors fall within FEMA-designated Special Flood Hazard Areas. Projects in these zones must comply with the city's floodplain management ordinance and may require an elevation certificate. Check your property's flood zone status using the FEMA Flood Map Service Center.
Impervious surface limits: Allentown enforces impervious surface coverage limits by zoning district to manage stormwater runoff. Adding a patio, driveway extension, or large shed could push your lot over the allowed percentage, requiring a stormwater management plan.
Lot coverage: Most residential zones cap total lot coverage (buildings plus impervious surfaces) at a defined percentage. Your site plan must clearly calculate and display existing and proposed coverage.

Typical Setback Requirements in Allentown

Setbacks vary by zoning district, but the following ranges are typical for Allentown residential properties:

Front yard setback: 15 to 30 feet from the front property line, depending on the district and prevailing setback of adjacent homes.
Side yard setback: 5 to 10 feet per side for detached single-family homes; rowhouse and twin-home lots may have zero side setbacks on the shared wall side.
Rear yard setback: 20 to 30 feet from the rear property line for principal structures; accessory structures like sheds and detached garages are often permitted closer, sometimes as little as 5 feet.
Accessory structure setbacks: Sheds and detached garages generally must be set back at least 5 feet from side and rear property lines and cannot be located in the front yard.

Always verify setbacks for your specific parcel and zoning district with the Allentown Bureau of Zoning, as corner lots, flag lots, and properties in overlay districts may have different requirements.

How to Submit a Permit Application in Allentown

Allentown has made progress toward digital permitting, and as of 2026, many permit applications can be initiated online through the city's permitting portal. Here is the general process:

Determine your zoning district by visiting the city's GIS mapping tool or contacting the Bureau of Zoning.
Prepare your site plan showing lot dimensions, existing structures, proposed work, setbacks, and impervious surface calculations. Site Plan Creator can generate a professional, permit-ready site plan in minutes.
Complete the permit application through the city's online portal or in person at the Bureau of Building Standards and Safety, located at City Hall, 435 Hamilton Street, Allentown, PA 18101.
Submit supporting documents, including construction drawings, contractor licenses, and any required HARB or floodplain documentation.
Pay the permit fee, which is calculated based on the estimated construction value of the project.
Await plan review. Residential permit reviews in Allentown typically take 2 to 4 weeks for straightforward projects, though complex additions or projects requiring HARB review can take longer.
Schedule inspections at required milestones (footing, framing, final) once your permit is approved and work begins.

Common Reasons Permit Applications Are Rejected in Allentown

Understanding why applications get kicked back can help you avoid delays:

Missing or incorrect setback dimensions on the site plan
No lot boundary dimensions or an unlabeled property survey
Impervious surface calculations missing or exceeding district limits
Incomplete contractor information or missing contractor registration with the city
No HARB approval for properties in historic overlay districts
Floodplain documentation missing for properties in or near flood zones
Site plan not drawn to scale or lacking a north arrow and scale bar
Proposed structure shown in a required setback without a variance application

Get Your Allentown Site Plan Ready Fast

Navigating Allentown's permit process does not have to be overwhelming. Site Plan Creator is designed for homeowners, contractors, and small builders who need a clean, accurate, permit-ready site plan without hiring a surveyor for every project. Our tool walks you through the required elements step by step, produces a scaled drawing you can submit to the Bureau of Building Standards and Safety, and saves you the back-and-forth of a rejected application. Start your Allentown site plan today at siteplancreator.com and move your project forward with confidence.

Frequently Asked Questions

Do I need a permit to build a deck in Allentown, PA?: Yes. In Allentown, any deck that is attached to the house or stands more than 30 inches above grade requires a building permit under the Pennsylvania Uniform Construction Code. You will need to submit a site plan showing the deck's dimensions, its distance from all property lines, and how it connects to the existing structure. The Bureau of Building Standards and Safety at City Hall reviews these applications. Permit fees are based on the estimated construction value of the project. Plan to allow two to four weeks for review on a straightforward deck permit. If your property is in a historic overlay district such as West Park, you may also need approval from the Historic and Architectural Review Board before the building permit is issued.
What are the setback requirements for a shed in Allentown?: In most Allentown residential zoning districts, accessory structures like sheds must be set back at least five feet from the rear property line and five feet from the side property line. Sheds are generally not permitted in the front yard. If your property is on a corner lot, additional setbacks from the street-side property line may apply. Sheds smaller than 200 square feet may not require a full building permit, but they still need to comply with zoning setback rules and may require a zoning permit. Sheds with electrical wiring or plumbing always require a building permit regardless of size. Confirm requirements for your specific parcel with the Allentown Bureau of Zoning before you begin construction.
How long does it take to get a building permit approved in Allentown, PA?: For most straightforward residential projects in Allentown, plan review takes approximately two to four weeks from the date a complete application is submitted. Projects that are incomplete, missing required documents, or located in special overlay zones such as the floodplain or a historic district can take considerably longer. Projects requiring Historic and Architectural Review Board (HARB) approval must complete that process before a building permit can be issued, which can add several weeks. To avoid delays, make sure your site plan is drawn to scale, includes all required setback dimensions, shows impervious surface calculations, and is accompanied by complete contractor documentation. Submitting a thorough application the first time is the best way to stay on schedule.
What does Allentown require on a residential site plan?: Allentown's Bureau of Building Standards and Safety expects a residential site plan to include: the legal dimensions of the lot and all property lines, the footprint and location of the existing house and any existing accessory structures, the proposed new construction drawn to scale with dimensions, the distances from all proposed structures to each property line (setbacks), the location of the driveway and any impervious surfaces with a coverage calculation, a north arrow, a graphic scale bar, and the property address. For projects near floodplains, a FEMA flood zone designation and, if required, an elevation certificate must accompany the plan. Properties in historic districts may need additional detail showing exterior materials and design elements for HARB review.
Can I draw my own site plan in Allentown, or do I need a licensed surveyor?: Pennsylvania law and Allentown's permit requirements do not always mandate a licensed surveyor or engineer for a basic residential site plan on simple projects like sheds, decks, or fences. Many homeowners and contractors prepare their own site plans using online tools such as Site Plan Creator, provided the drawing is accurate, drawn to scale, and includes all required elements. However, if your project involves structural engineering (such as a large addition or a pool with complex grading), if your property boundaries are disputed, or if you are in a floodplain requiring an elevation certificate, you will likely need a licensed professional. When in doubt, contact the Allentown Bureau of Building Standards and Safety before submitting to confirm what level of professional certification your specific project requires.
How much does a building permit cost in Allentown, PA?: Allentown calculates building permit fees based on the estimated construction value of the proposed project. The fee schedule is tiered, so larger and more expensive projects pay higher fees. As a general reference, smaller projects like sheds or simple decks might carry permit fees in the range of a few hundred dollars, while larger additions or new accessory dwelling units can result in fees of several hundred to over a thousand dollars depending on construction value. There may also be separate zoning review fees, plan review fees, and inspection fees. Because the fee schedule can be updated, contact the Bureau of Building Standards and Safety at (610) 437-7579 or visit City Hall at 435 Hamilton Street to get the current fee schedule before budgeting your project.
What happens if I build without a permit in Allentown?: Building without a required permit in Allentown is a violation of the Pennsylvania Uniform Construction Code and the city's local ordinances. If discovered, the city can issue a stop-work order immediately halting all construction. You may be required to obtain a retroactive permit, which often means opening up finished work so inspectors can verify code compliance. Fines and penalties can accumulate daily until the violation is resolved. Unpermitted work can also create serious problems when you sell your home, as title searches and home inspections often uncover missing permits, which can delay or kill a sale. In some cases, unpermitted structures must be removed entirely. It is always less expensive and less stressful to pull the permit before you build.
Are ADUs or garage conversions allowed in Allentown, PA?: Accessory dwelling units, including basement apartments, garage conversions, and carriage house units, are permitted in some Allentown residential zoning districts but are subject to specific regulations. The zoning district, lot size, parking availability, and owner-occupancy requirements all affect whether an ADU is allowed on a given property. Any ADU project requires a building permit, a zoning review, and a site plan demonstrating compliance with setbacks, lot coverage limits, and utility connections. Pennsylvania has been encouraging municipalities to allow more ADUs to address housing supply, so rules in Allentown may continue to evolve in 2026. Contact the Allentown Bureau of Zoning directly to confirm what is permitted for your specific parcel before investing in design or construction.
Does my Allentown property fall in a FEMA floodplain, and does that affect my permit?: Parts of Allentown along the Little Lehigh Creek, Jordan Creek, and their tributaries fall within FEMA-designated Special Flood Hazard Areas (SFHAs). If your property is in or near one of these zones, it can significantly affect your permit requirements. Projects in an SFHA may require a floodplain development permit in addition to the standard building permit, and you may need to provide an elevation certificate prepared by a licensed surveyor. New construction or substantial improvements in a floodplain must meet minimum finished floor elevation requirements. You can check your property's flood zone status using the FEMA Flood Map Service Center at msc.fema.gov. Allentown's floodplain administrator is located within the Bureau of Building Standards and Safety and can answer specific questions about your parcel.
Where do I submit a permit application in Allentown, PA?: Permit applications for residential projects in Allentown can be submitted in person at the Bureau of Building Standards and Safety, located at City Hall, 435 Hamilton Street, Allentown, PA 18101. As of 2026, the city also offers online permit initiation through its digital permitting portal for many project types, allowing you to upload your site plan and supporting documents electronically. For complex projects or those requiring HARB review, in-person submission and pre-application meetings with city staff are often advisable. The bureau can be reached by phone at (610) 437-7579. Staff can confirm whether your specific project type is eligible for online submission or requires an in-person visit and can provide the current permit application forms and fee schedule.

How to Create a Site Plan in Allentown

Confirm Your Zoning District: Before designing your project, identify your Allentown zoning district using the city's online GIS mapping tool or by contacting the Bureau of Zoning at City Hall. Your district determines what you can build, where on your lot you can build it, and what setbacks apply. Properties in historic overlay districts or floodplain zones have additional requirements that must be identified at the start of the process to avoid costly surprises later.
Prepare Your Site Plan: Create a scaled site plan that shows your lot boundaries with dimensions, the footprint of your existing home and all structures, the proposed new construction with dimensions, setback distances from all property lines, impervious surface calculations, a north arrow, and a scale bar. Site Plan Creator makes this step fast and straightforward, producing a permit-ready drawing that meets Allentown's Bureau of Building Standards and Safety requirements without requiring a professional surveyor for most simple residential projects.
Gather Supporting Documents: Assemble all required supporting materials before submitting. This typically includes a completed permit application form, your scaled site plan, construction drawings or specifications for the proposed work, contractor license and insurance information if using a contractor, and any special documentation such as a HARB approval letter for historic district properties or a FEMA elevation certificate for floodplain properties. Having everything ready before submission prevents delays and back-and-forth with city staff.
Submit Application and Pay Fees: Submit your complete permit application package to the Allentown Bureau of Building Standards and Safety, either in person at 435 Hamilton Street or through the city's online permitting portal if your project type is eligible. Pay the applicable permit fee, which is calculated based on the estimated construction value of your project. Keep your receipt and application number, as you will need them to track your review status and schedule inspections once the permit is approved.
Respond to Plan Review Comments: After submission, a city plan reviewer will evaluate your application for compliance with the Pennsylvania Uniform Construction Code and Allentown's zoning ordinance. If the reviewer has questions or identifies deficiencies, you will receive a correction notice. Respond promptly with revised documents or clarifications. Common corrections involve missing setback dimensions, impervious surface calculations, or incomplete contractor information. Addressing comments quickly keeps your project moving toward permit issuance.
Schedule Required Inspections: Once your permit is issued, post it visibly at the job site and begin construction. Contact the Bureau of Building Standards and Safety to schedule required inspections at key milestones, typically including footing or foundation inspection, framing inspection, and a final inspection upon project completion. Do not cover or conceal work before the required inspection is completed and approved. A final inspection sign-off closes out your permit and confirms your project is code-compliant.