Do I need a permit to build a deck in Cary, NC?

Yes. Any deck attached to your home, or any freestanding deck elevated more than 30 inches above grade, requires a building permit in Cary. You will also need to submit a residential site plan showing the deck's footprint, its distance from all property lines, and how it relates to the existing house. The Town of Cary's Development Services Center reviews these applications and checks compliance with the Cary Land Development Ordinance and the North Carolina Residential Building Code. Permit fees are based on the estimated construction value. Most straightforward deck permits are reviewed within 5 to 10 business days. Skipping the permit can result in a stop-work order, fines, and a requirement to remove the structure.

How much does a site plan or building permit cost in Cary, NC?

Permit fees in Cary are calculated based on the estimated construction value of the project. As a general benchmark, residential building permits typically start around $50 to $100 for very minor work and scale upward from there. A deck valued at $15,000 might carry a permit fee in the range of $150 to $300, while a room addition or ADU could see fees of several hundred dollars or more. Plan review fees are often included in the building permit fee. Zoning review fees may be assessed separately. For the most current fee schedule, contact the Town of Cary Development Services Center at (919) 469-4090 or visit their website, as fees are updated periodically and project-specific variables can affect the final amount.

How long does it take to get a building permit approved in Cary, NC?

For standard residential projects such as decks, sheds, pools, and additions, Cary's plan review typically takes 5 to 10 business days after a complete application is submitted. Projects that require additional zoning review, variance approval, or floodplain analysis can take significantly longer, sometimes several weeks. Incomplete applications, missing site plan elements, or impervious surface issues are the most common causes of delays. Cary offers online permit submission through its Energov portal, which tends to process faster than paper submissions. If your project is time-sensitive, confirm with Development Services whether an expedited review option is available and what the associated fee would be.

What does Cary, NC require on a residential site plan?

A residential site plan submitted to the Town of Cary must be drawn to scale and include the following: lot dimensions and total lot area, the location and footprint of all existing structures on the property, the proposed new structure or improvement with all dimensions shown, setback distances from every property line, the location of any easements (utility, drainage, or access), impervious surface calculations showing existing and proposed hard-surface coverage, and identification of any regulated trees or stream buffers near the work area. For projects near FEMA-designated floodplains, base flood elevation data may also be required. The plan should reference the recorded plat and include the property address and owner information.

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

For most standard residential permits in Cary, you are not required to hire a licensed land surveyor or engineer to prepare your site plan. Many homeowners successfully draw their own site plans using plat maps from Wake County's GIS records as a base and then adding proposed improvements with accurate dimensions. However, the plan must be drawn to scale and contain all required elements. If your lot has complex boundaries, easements, or is near a floodplain, a professional survey is strongly recommended. Tools like Site Plan Creator make it easy for homeowners to produce accurate, permit-ready drawings without professional drafting experience. More complex projects, such as large additions or ADUs, may benefit from professional assistance.

What are the setback requirements for residential properties in Cary, NC?

Setbacks in Cary vary by zoning district, but typical single-family residential zones require a front yard setback of 20 to 30 feet from the front property line, side yard setbacks of 5 to 10 feet per side, and a rear yard setback of 20 to 25 feet. Corner lots have larger setbacks on the street-facing side. Accessory structures like detached garages and sheds may have reduced setbacks, often 5 feet from the side and rear lines. These are general ranges; your specific zoning district's requirements are listed in the Cary Land Development Ordinance. Always verify your parcel's zoning classification and the applicable setback table before finalizing your site plan.

Where do I submit a site plan or permit application in Cary, NC?

Cary accepts residential permit applications both online and in person. The preferred method is the town's online permitting portal (Energov, accessed through the Cary website), which allows you to upload your site plan, application forms, and supporting documents digitally and track your application status. In-person submissions are accepted at the Town of Cary Development Services Center, located at 316 N. Academy St., Cary, NC 27513. The office is open during regular business hours Monday through Friday. Online submission is generally faster and reduces the need for multiple trips to the office. For questions before submitting, call Development Services at (919) 469-4090.

What happens if I build without a permit in Cary, NC?

Building without a required permit in Cary can have serious consequences. The town's inspectors can issue a stop-work order, halting all construction immediately. You may be required to pay double permit fees as a penalty. In some cases, unpermitted structures must be removed or brought into full compliance before the property can be sold or refinanced, since lenders and title companies often flag open permit issues. If the unpermitted work is discovered during a real estate transaction, it can delay or kill the sale. Additionally, homeowner's insurance may deny claims related to unpermitted improvements. It is always less expensive and less stressful to pull the permit before work begins rather than after the fact.

Does Cary, NC allow accessory dwelling units (ADUs), and what are the rules?

Yes, Cary allows accessory dwelling units on single-family lots, subject to specific standards in the Land Development Ordinance. ADUs can be detached structures, attached additions, or interior conversions such as a basement apartment. Key requirements include minimum lot size thresholds, a cap on the ADU's square footage relative to the primary home, owner-occupancy requirements in some cases, adequate off-street parking, and compliance with all applicable setbacks. A full building permit and site plan are required. ADUs must also meet utility connection standards and may require separate water and sewer taps depending on the configuration. Given the complexity of ADU regulations, it is advisable to consult with Cary's Development Services Center early in the planning process.

Are there impervious surface limits I need to know about in Cary, NC?

Yes, impervious surface limits are one of the most important and frequently overlooked aspects of residential permitting in Cary. Impervious surfaces include roofs, driveways, patios, decks with solid decking, and any other hard surface that prevents rainwater from soaking into the ground. Depending on your zoning district, Cary limits impervious coverage to roughly 35% to 60% of the total lot area. Your site plan must include a calculation showing existing impervious coverage and the coverage added by the proposed project. If your lot is already near its limit, a new addition, pool, or expanded driveway could push you over the threshold and require design changes or stormwater mitigation measures before the permit can be approved.

Site Plan Requirements in Cary, NC (Permit Guide)

By Site Plan Creator Team • June 6, 2026

Cary, NC is one of the fastest-growing towns in the country, and its development services office enforces detailed site plan requirements for most residential projects. Whether you are building a deck, adding an ADU, or installing a pool, understanding Cary's permit process upfront will save you time and money. This guide covers everything homeowners and contractors need to know about site plans and permits in Cary.

Site plan requirements for residential properties in Cary, North Carolina

Residential Site Plans and Permits in Cary, NC

Cary, North Carolina has earned a reputation as one of the most desirable and well-planned communities in the Research Triangle region. With a population now exceeding 185,000 and consistent ranking among the best places to live in the United States, Cary takes land use, stormwater management, and neighborhood character seriously. That commitment translates directly into a thorough permitting process: virtually any structural improvement to your property, from a backyard deck to a detached garage, will require a permit and, in most cases, a residential site plan submitted to the Town of Cary's Development Services department.

Understanding what Cary requires before you break ground is critical. Unpermitted work can trigger stop-work orders, fines, and costly removal orders. This guide walks you through the key triggers, local zoning quirks, setback requirements, submission procedures, and the most common reasons applications get rejected.

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

A residential site plan is a scaled, bird's-eye drawing of your property that shows the lot boundaries, existing structures, proposed improvements, setbacks from property lines, easements, driveways, impervious surfaces, and any relevant natural features such as streams or tree-protection zones. Cary requires site plans because the town must verify that your project:

Complies with the Cary Land Development Ordinance (LDO)
Respects required setbacks from property lines and easements
Does not exceed impervious surface limits for your zoning district
Protects regulated trees, buffers, and floodplain areas
Aligns with stormwater runoff standards

The Town of Cary administers permits and plan review through its Development Services Center. North Carolina's statewide building code is maintained by the NC Department of Insurance Office of State Fire Marshal, and local amendments build on that foundation.

Residential Permit Triggers in Cary

Not every home project requires a full site plan, but most structural work does require at least a building permit. Here are the most common residential triggers in Cary:

Decks and Porches

Any deck attached to the home or elevated more than 30 inches above grade requires a building permit and a site plan showing the deck's footprint, setbacks, and relationship to the house.

Sheds and Accessory Structures

Detached storage buildings over 144 square feet (roughly 12x12) require a permit. Smaller sheds may be exempt from a building permit but still must meet zoning setbacks. A site plan is typically required to confirm placement.

Swimming Pools

In-ground and above-ground pools over 24 inches deep require a building permit, an electrical permit, and a site plan. Barrier and fencing requirements under the North Carolina Residential Code also apply.

Fences

Fences in Cary generally do not require a building permit, but they must comply with height limits and setback rules in the LDO. Fences in front yards are limited to 4 feet; rear and side yard fences may be up to 6 feet. HOA rules may be stricter.

Room Additions and Home Expansions

All additions require a building permit and a detailed site plan. Impervious surface calculations are especially important here, as Cary limits the total hard surface coverage on most residential lots.

Accessory Dwelling Units (ADUs)

Cary amended its LDO in recent years to allow ADUs (also called secondary dwelling units) on single-family lots under certain conditions. ADUs require a full building permit, a site plan, and must meet specific standards for size, setbacks, parking, and utility connections. The maximum size for a detached ADU is typically capped as a percentage of the primary dwelling's square footage.

Driveways

New driveways or significant expansions require a zoning permit and, in some cases, a driveway permit from the Town. Impervious surface limits apply, and connections to public streets may require approval from the Town's Transportation and Facilities Department.

Zoning Quirks and Local Considerations in Cary

Cary has several locally specific planning considerations that homeowners should be aware of:

Impervious Surface Limits: Cary enforces strict limits on how much of a lot can be covered by hard surfaces (roofs, driveways, patios, decks with solid surfaces). Depending on your zoning district, this limit typically ranges from 35% to 60% of the lot area. Exceeding this limit can prevent approval of an otherwise code-compliant project.

Tree Preservation: Cary's tree ordinance protects significant trees and requires tree-save areas on many lots. Your site plan must identify any regulated trees near the construction zone, and tree-protection fencing may be required before inspections begin.

Floodplain Awareness: Parts of Cary lie within FEMA-designated Special Flood Hazard Areas, particularly near Swift Creek, Crabtree Creek, and their tributaries. Projects in or near floodplains require additional review and may need elevation certificates. Check your property's flood status at the FEMA Flood Map Service Center.

HOA Overlay: A large percentage of Cary's residential neighborhoods are governed by homeowners associations. HOA approval is separate from town permits and is often required before construction begins. Always check with your HOA before submitting to the town.

Historic and Established Neighborhoods: While Cary does not have a large historic district overlay compared to some cities, older neighborhoods near downtown Cary may have additional design standards under the LDO.

Typical Setback Requirements in Cary

Setbacks vary by zoning district, but the following ranges are typical for standard single-family residential (R-) zones in Cary:

Front yard setback: 20 to 30 feet from the front property line
Side yard setback: 5 to 10 feet per side (interior lots); corner lots have larger street-side setbacks
Rear yard setback: 20 to 25 feet from the rear property line
Accessory structures (sheds, garages): Reduced setbacks may apply, often 5 feet from side and rear lines

Always verify your specific zoning district's setbacks in the Cary Land Development Ordinance before finalizing your site plan.

The Permit Submission Process in Cary

Step 1: Determine Your Project Type

Before submitting anything, confirm whether your project requires a building permit, a zoning permit, or both. The Town of Cary's Development Services Center can help you make this determination.

Step 2: Prepare Your Site Plan

Your site plan must be drawn to scale and include lot dimensions, all existing and proposed structures, setback dimensions, impervious surface calculations, easements, and any regulated natural features. Many homeowners use tools like Site Plan Creator to produce professional, permit-ready drawings without hiring a full survey team.

Step 3: Submit Online or In Person

Cary accepts permit applications through its online permitting portal (Energov/MyGovernmentOnline) as well as in person at the Development Services Center located at 316 N. Academy St., Cary, NC 27513. Online submission is strongly encouraged and often results in faster processing.

Step 4: Plan Review

Residential plan review in Cary typically takes 5 to 10 business days for standard projects. More complex projects, or those requiring zoning board review, can take several weeks. Expedited review options may be available for an additional fee.

Step 5: Permit Issuance and Inspections

Once approved, your permit is issued and work may begin. Required inspections (footing, framing, final) must be scheduled through the town's inspection scheduling system. A final inspection sign-off is required to close the permit.

Common Reasons Site Plan Applications Are Rejected in Cary

Missing or incorrect setback dimensions: The plan does not clearly show distances from all proposed structures to property lines.
Impervious surface calculations omitted or exceeded: No calculation is provided, or the project would push the lot over the allowable limit.
Unidentified easements: Utility or drainage easements cross the construction area but are not shown.
Incomplete tree identification: Regulated trees near the project are not identified or the tree-save plan is missing.
Scale errors: The plan is not drawn to a recognized scale, making dimensions unverifiable.
Missing survey or deed information: Lot dimensions do not match recorded plat data.

Get Your Cary Site Plan Right the First Time

Navigating Cary's permit requirements can feel overwhelming, especially for first-time applicants. Site Plan Creator is designed to help homeowners and small contractors produce accurate, professional, permit-ready residential site plans quickly and affordably. With an intuitive interface and built-in tools for measuring setbacks, calculating impervious surfaces, and labeling all required elements, you can submit with confidence.

Start your Cary site plan today at siteplancreator.com and move your project forward without the guesswork.

Frequently Asked Questions

Do I need a permit to build a deck in Cary, NC?: Yes. Any deck attached to your home, or any freestanding deck elevated more than 30 inches above grade, requires a building permit in Cary. You will also need to submit a residential site plan showing the deck's footprint, its distance from all property lines, and how it relates to the existing house. The Town of Cary's Development Services Center reviews these applications and checks compliance with the Cary Land Development Ordinance and the North Carolina Residential Building Code. Permit fees are based on the estimated construction value. Most straightforward deck permits are reviewed within 5 to 10 business days. Skipping the permit can result in a stop-work order, fines, and a requirement to remove the structure.
How much does a site plan or building permit cost in Cary, NC?: Permit fees in Cary are calculated based on the estimated construction value of the project. As a general benchmark, residential building permits typically start around $50 to $100 for very minor work and scale upward from there. A deck valued at $15,000 might carry a permit fee in the range of $150 to $300, while a room addition or ADU could see fees of several hundred dollars or more. Plan review fees are often included in the building permit fee. Zoning review fees may be assessed separately. For the most current fee schedule, contact the Town of Cary Development Services Center at (919) 469-4090 or visit their website, as fees are updated periodically and project-specific variables can affect the final amount.
How long does it take to get a building permit approved in Cary, NC?: For standard residential projects such as decks, sheds, pools, and additions, Cary's plan review typically takes 5 to 10 business days after a complete application is submitted. Projects that require additional zoning review, variance approval, or floodplain analysis can take significantly longer, sometimes several weeks. Incomplete applications, missing site plan elements, or impervious surface issues are the most common causes of delays. Cary offers online permit submission through its Energov portal, which tends to process faster than paper submissions. If your project is time-sensitive, confirm with Development Services whether an expedited review option is available and what the associated fee would be.
What does Cary, NC require on a residential site plan?: A residential site plan submitted to the Town of Cary must be drawn to scale and include the following: lot dimensions and total lot area, the location and footprint of all existing structures on the property, the proposed new structure or improvement with all dimensions shown, setback distances from every property line, the location of any easements (utility, drainage, or access), impervious surface calculations showing existing and proposed hard-surface coverage, and identification of any regulated trees or stream buffers near the work area. For projects near FEMA-designated floodplains, base flood elevation data may also be required. The plan should reference the recorded plat and include the property address and owner information.
Can I draw my own site plan in Cary, or do I need a licensed surveyor?: For most standard residential permits in Cary, you are not required to hire a licensed land surveyor or engineer to prepare your site plan. Many homeowners successfully draw their own site plans using plat maps from Wake County's GIS records as a base and then adding proposed improvements with accurate dimensions. However, the plan must be drawn to scale and contain all required elements. If your lot has complex boundaries, easements, or is near a floodplain, a professional survey is strongly recommended. Tools like Site Plan Creator make it easy for homeowners to produce accurate, permit-ready drawings without professional drafting experience. More complex projects, such as large additions or ADUs, may benefit from professional assistance.
What are the setback requirements for residential properties in Cary, NC?: Setbacks in Cary vary by zoning district, but typical single-family residential zones require a front yard setback of 20 to 30 feet from the front property line, side yard setbacks of 5 to 10 feet per side, and a rear yard setback of 20 to 25 feet. Corner lots have larger setbacks on the street-facing side. Accessory structures like detached garages and sheds may have reduced setbacks, often 5 feet from the side and rear lines. These are general ranges; your specific zoning district's requirements are listed in the Cary Land Development Ordinance. Always verify your parcel's zoning classification and the applicable setback table before finalizing your site plan.
Where do I submit a site plan or permit application in Cary, NC?: Cary accepts residential permit applications both online and in person. The preferred method is the town's online permitting portal (Energov, accessed through the Cary website), which allows you to upload your site plan, application forms, and supporting documents digitally and track your application status. In-person submissions are accepted at the Town of Cary Development Services Center, located at 316 N. Academy St., Cary, NC 27513. The office is open during regular business hours Monday through Friday. Online submission is generally faster and reduces the need for multiple trips to the office. For questions before submitting, call Development Services at (919) 469-4090.
What happens if I build without a permit in Cary, NC?: Building without a required permit in Cary can have serious consequences. The town's inspectors can issue a stop-work order, halting all construction immediately. You may be required to pay double permit fees as a penalty. In some cases, unpermitted structures must be removed or brought into full compliance before the property can be sold or refinanced, since lenders and title companies often flag open permit issues. If the unpermitted work is discovered during a real estate transaction, it can delay or kill the sale. Additionally, homeowner's insurance may deny claims related to unpermitted improvements. It is always less expensive and less stressful to pull the permit before work begins rather than after the fact.
Does Cary, NC allow accessory dwelling units (ADUs), and what are the rules?: Yes, Cary allows accessory dwelling units on single-family lots, subject to specific standards in the Land Development Ordinance. ADUs can be detached structures, attached additions, or interior conversions such as a basement apartment. Key requirements include minimum lot size thresholds, a cap on the ADU's square footage relative to the primary home, owner-occupancy requirements in some cases, adequate off-street parking, and compliance with all applicable setbacks. A full building permit and site plan are required. ADUs must also meet utility connection standards and may require separate water and sewer taps depending on the configuration. Given the complexity of ADU regulations, it is advisable to consult with Cary's Development Services Center early in the planning process.
Are there impervious surface limits I need to know about in Cary, NC?: Yes, impervious surface limits are one of the most important and frequently overlooked aspects of residential permitting in Cary. Impervious surfaces include roofs, driveways, patios, decks with solid decking, and any other hard surface that prevents rainwater from soaking into the ground. Depending on your zoning district, Cary limits impervious coverage to roughly 35% to 60% of the total lot area. Your site plan must include a calculation showing existing impervious coverage and the coverage added by the proposed project. If your lot is already near its limit, a new addition, pool, or expanded driveway could push you over the threshold and require design changes or stormwater mitigation measures before the permit can be approved.

How to Create a Site Plan in Cary

Confirm Your Permit Requirements: Start by determining exactly which permits your project requires. Visit the Town of Cary Development Services Center website or call (919) 469-4090 to confirm whether your project needs a building permit, a zoning permit, or both. Check your zoning district in the Cary Land Development Ordinance to understand applicable setbacks, impervious surface limits, and any overlay requirements such as floodplain or tree-protection zones that may affect your plans.
Gather Your Property Documents: Obtain a copy of your recorded plat from the Wake County Register of Deeds or the Wake County GIS portal. This document shows your lot's official boundaries, dimensions, and any recorded easements. You will use this as the base for your site plan. Also note your current impervious surface coverage by measuring all existing hard surfaces, since Cary requires this calculation as part of most residential permit applications.
Draw Your Residential Site Plan: Create a scaled site plan that includes lot boundaries, all existing structures, the proposed improvement with dimensions, setback distances from all property lines, easements, impervious surface calculations, and any regulated trees or stream buffers. Site Plan Creator provides an easy-to-use online tool that guides you through each required element and produces a clean, professional drawing suitable for submission to Cary's Development Services Center.
Submit Your Application to Cary: Submit your completed permit application, site plan, and any required supporting documents through Cary's online Energov permitting portal or in person at 316 N. Academy St., Cary, NC 27513. Online submission is preferred and typically results in faster processing. Ensure all forms are complete and all required documents are attached before submitting to avoid delays caused by incomplete applications.
Respond to Plan Review Comments: After submission, Cary's plan reviewers will examine your application for compliance with the Land Development Ordinance and the North Carolina Residential Building Code. Standard review takes 5 to 10 business days. If reviewers identify issues such as setback violations, missing impervious surface data, or unidentified easements, they will issue correction comments. Respond promptly with revised drawings or additional information to keep your project on schedule.
Schedule Required Inspections: Once your permit is issued and construction begins, schedule all required inspections through Cary's inspection scheduling system. Typical inspections include footing or foundation, framing, and final inspection. Do not cover work before the appropriate inspection is completed and approved. A final inspection sign-off is required to officially close your permit, which is important for future property sales, refinancing, and homeowner's insurance purposes.