If you are applying for a building permit, zoning review, or HOA approval, you may be asked for a site plan, a survey, or sometimes both. These documents are related, but they are not the same. A site plan usually shows how a proposed project fits on the property. A survey is usually prepared by a licensed land surveyor to verify property boundaries, measurements, easements, and other legal or field-based property information.

For many simple residential projects, a permit office may accept a clear site plan. For projects near property lines, projects with boundary questions, or applications that specifically require a survey, a survey may be needed. The best choice depends on the project type, local permit rules, and how accurate the property boundary information needs to be.

Simple Difference Between a Site Plan and a Survey

The easiest way to understand the difference is this:

• Site plan: Shows the property layout and how the proposed project fits on the lot.
• Survey: Verifies property boundaries, dimensions, corners, easements, and existing improvements using professional surveying methods.

A site plan is usually used to explain a project. A survey is usually used to confirm property information. Some permit offices only need the project layout. Others need boundary information verified by a licensed surveyor.

What Is a Site Plan?

A site plan is a drawing that shows what exists on a property and what is being proposed. It is usually drawn from above and may show the house, garage, driveway, sidewalk, proposed project, setbacks, access, utilities, easements, drainage direction, and other site details.

The City of Bellevue describes a residential site plan as a drawing of what is existing and what is proposed on a lot. Bellevue also says property lines, setback distances, streets, rights-of-way, and easements must be verified and accurately shown. Source: City of Bellevue – Residential Site Plan.

The City of Salem describes a site plan as an accurately scaled drawing that shows existing conditions and proposed improvements, including structures, paving, utility services, and land uses. Source: City of Salem – Prepare a Site Plan.

Homeowners preparing for permit review can also use our permit site plan checklist to see the property and project details commonly shown.

What Is a Survey?

A survey is a professional document prepared by a licensed land surveyor. It is used to identify, measure, and document property boundaries, corners, easements, existing improvements, encroachments, and other land information depending on the type of survey ordered.

State surveying regulations often define boundary surveying as a professional process that uses recorded evidence, field evidence, and other relevant sources to form an opinion about where property boundaries are located. Source: Rhode Island Board of Registration for Professional Land Surveyors – Rules and Regulations.

In simple terms, a survey is about proving or verifying the property information. A site plan is about showing the proposed project on the property.

Why Permit Offices Ask for Site Plans

Permit offices use site plans to understand where the work will happen and how it fits on the lot. The drawing helps reviewers check project location, setbacks, access, lot coverage, utilities, drainage, and nearby structures.

The International Residential Code says construction documents submitted with a permit application should be accompanied by a site plan or plot plan showing the size and location of new construction, existing structures on the site, and distances from lot lines. Source: International Code Council – IRC R106.2 Site Plan or Plot Plan.

That means a basic permit site plan often needs to answer a few clear questions: what exists, what is proposed, where is it located, and how far is it from the property lines?

Our guide explaining what permit reviewers check first on a site plan covers the information that should be easy to find at a glance.

Why Permit Offices Ask for Surveys

A permit office may ask for a survey when the property boundary, easements, legal lot information, or exact structure location must be verified. This can happen when the project is close to a property line, when the city requires a survey for that type of permit, or when public records and homeowner measurements are not enough.

A survey may be especially important when:

• The proposed work is close to a property line
• The property line location is uncertain
• There is a boundary dispute
• The project may affect an easement
• The permit office specifically requires a survey
• The project involves a new home, addition, ADU, garage, pool, retaining wall, or driveway near a lot line
• The property has unusual shape, unclear records, or conflicting measurements

If exact boundary location matters, a professionally prepared survey is usually the safer document.

What a Site Plan Usually Includes

A typical residential site plan may include:

• Property lines and lot dimensions
• Existing house or main structure
• Existing garage, shed, deck, patio, pool, driveway, or walkway
• Proposed project location
• Project dimensions
• Setback distances from property lines
• Distance from proposed work to existing structures
• Driveway, sidewalk, alley, road, or access labels
• Utilities when known or provided
• Easements when available
• Drainage direction when relevant
• North arrow and scale

A site plan is often enough for simple projects when the permit office does not require a licensed survey and the property boundaries are already clear enough for review.

What a Survey Usually Includes

A survey may include more formal property information, such as:

• Legal property boundaries
• Property corners or monuments
• Bearings and distances
• Lot area
• Recorded easements
• Existing improvements
• Encroachments when identified
• Rights-of-way
• Surveyor certification
• Field-measured boundary information

Depending on the survey type, it may also show topography, flood information, title items, building locations, utilities, or other site conditions. The exact content depends on what is ordered and what the permit office requires.

When a Site Plan May Be Enough

A site plan may be enough when the permit office mainly needs to see the project location, setbacks, and general property layout.

Common examples may include:

• Small sheds
• Simple decks
• Fences
• Patios
• Minor driveway layouts
• Basic pool equipment placement
• HOA project exhibits
• Simple accessory structures

Even when a site plan is enough, it should still be clear and accurate. It should show the property lines, existing structures, proposed work, dimensions, setbacks, access, and other details your permit office asks for.

Project-specific guidance is available for shed permits, deck permits, fence permits, and pool permits.

When You May Need a Survey

A survey may be needed when the permit office requires verified boundary information or when the project depends on exact property line placement.

You may need a survey for:

• New home construction
• Major additions
• ADUs or detached dwelling units
• Detached garages close to lot lines
• Retaining walls near property boundaries
• Fences where the property line is disputed
• Pools or decks close to setbacks
• Driveways near side lot lines or easements
• Projects in easements or near recorded restrictions
• Properties with unclear or conflicting boundary information

If a city, county, or HOA says a survey is required, a basic site plan cannot replace it. In that case, a licensed surveyor should be hired.

Larger projects may also benefit from reviewing the individual guides for home additions, ADUs, garages, and retaining walls.

Can a Site Plan Be Made from a Survey?

Yes. A survey can be a strong starting point for a site plan. If you already have a recent survey, the site plan can often use the survey as a base and add the proposed project, permit labels, setback dimensions, driveway notes, and other project-specific information.

This is often the best approach when accuracy matters. The survey confirms the property information, and the site plan explains the project.

Can a Site Plan Replace a Survey?

Sometimes, but not always. A site plan can often be used for basic permit or HOA review when a survey is not required. However, it should not be treated as a legal boundary survey unless it was prepared and certified by a licensed land surveyor.

If the permit office asks for a survey, or if property line accuracy is legally important, a site plan alone may not be enough.

Site Plan vs Survey for Setbacks

Setbacks are one of the biggest reasons this question comes up. A setback is the required distance between a structure and a property line or other regulated area.

A site plan can show setback measurements. But if the property line location is uncertain, the setback measurement may also be uncertain. That is when a survey can become important.

For example, if a shed must be 5 feet from the side property line and you are placing it 20 feet away, a basic site plan may be enough in many areas. But if the shed is planned only 5 feet from the property line, the permit office may want stronger proof that the property line is correctly located.

Site Plan vs Survey for Fences

Fence projects often create confusion because fences are usually built near property lines. A site plan can show the proposed fence layout, gate location, height, and general lot layout. But a survey may be needed if the fence is intended to sit on or near the legal boundary.

If you are not sure where the property line is, do not rely only on an old fence, hedge, tree row, or driveway edge. Those features may not match the legal boundary.

Our fence permit site plan guide explains the boundary, height, gate and visibility details that may be requested.

Site Plan vs Survey for Additions and ADUs

Additions and ADUs often need more careful review because they can affect lot coverage, utilities, drainage, building separation, and setbacks. A site plan can show the proposed layout, but a survey may be needed if the new structure is close to lot lines or if the permit office requires verified boundary information.

For larger projects, the permit package may include both documents: a survey to establish the boundary information and a site plan to show the proposed building layout.

The same issue can arise for enclosed projects such as a screened porch or sunroom addition, particularly when the new footprint approaches a setback or changes lot coverage.

What Should Homeowners Order First?

If your permit office clearly asks for a survey, order a survey from a licensed land surveyor first. If your permit office asks for a site plan and does not require a survey, a site plan may be the right starting point.

If you are unsure, check the permit checklist or ask the permit office whether a survey is required for your specific project. The answer may depend on project type, location, zoning rules, and how close the proposed work is to the property lines.

Practical Rule of Thumb

Here is the simple homeowner version:

• Use a site plan when you need to show project placement, setbacks, access, and property layout for permit or HOA review.
• Use a survey when you need to verify legal property boundaries, corners, easements, or exact boundary-related measurements.
• Use both when the project needs verified boundary information and a clear proposed construction layout.

Common Mistakes to Avoid

Homeowners often run into problems when they assume one document can do everything. Common mistakes include:

• Assuming a site plan is the same as a legal survey
• Using a fence line as the property line
• Ordering a site plan when the city specifically requires a survey
• Submitting an old survey that does not show current improvements
• Forgetting to show the proposed project on top of the survey
• Not checking easements before planning construction
• Building close to a property line without verifying the boundary
• Not checking the local permit checklist before ordering drawings

Before submitting, it is also worth reviewing why site plans get rejected or delayed so missing measurements and unclear property information can be corrected early.

Final Thoughts

A site plan and a survey serve different purposes. A site plan is usually used to show how a proposed project fits on a property. A survey is used to verify property boundaries and other recorded or field-measured property information.

For many simple permits, a clear site plan may be enough. For projects close to property lines, projects with boundary questions, or permit applications that specifically require a survey, a survey may also be needed. The best approach is to check your local permit requirements before submitting.

Sources

• International Code Council – IRC R106.2 Site Plan or Plot Plan
• City of Bellevue – Residential Site Plan
• City of Salem – Prepare a Site Plan
• Rhode Island Board of Registration for Professional Land Surveyors – Rules and Regulations