How to Draw a Site Plan for a Residential Building Permit in City of Sarnia

If you are applying for a residential building permit in City of Sarnia, the site plan is the drawing that shows where the work will sit on your lot. City of Sarnia's permit guides ask for site plans for projects such as detached accessory buildings, decks, and above ground pools, with enough property measurements, structure locations, dimensions, septic information, and setbacks for the building review.

This guide explains how to draw a site plan for a residential building permit in City of Sarnia, what to include for common homeowner projects, and how to prepare a clear hand-drawn or survey-based drawing.

What is a site plan?

Site plan definition

A site plan is a top-down drawing of your property. It shows the lot, the dwelling, existing buildings or structures, the proposed work, and the measurements that explain where everything is located.

For a homeowner, a site plan for property answers practical permit questions: how big is the lot, where is the house, where is the proposed shed, garage, deck, pool, or fence enclosure, and how far is it from property lines, other structures, and septic components? A site plan for a residential building permit helps City of Sarnia review the proposed location before the permit is issued.

Common site plan terminology

Do you need a site plan?

You should expect to provide a site plan when the City of Sarnia permit package involves a new exterior structure or a project with a specific location on the lot. City of Sarnia's residential guides identify site plans for detached residential accessory buildings, decks, and above ground pools.

For a shed, garage, gazebo, sun shelter, or similar accessory building, the site plan needs to show the property, the dwelling, other buildings, and the proposed accessory building location. For a deck, the drawing needs enough context to show the proposed deck in relation to property lines, structures, and septic components. For an above ground pool, City of Sarnia asks for the proposed pool, the pool fence enclosure and gate, adjacent buildings, septic system information, and setbacks.

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Site plan requirements for residential building permits in City of Sarnia

A useful City of Sarnia site plan should be legible, scaled or clearly dimensioned, and focused on the review questions for your project. Include:

• Property measurements or lot dimensions
• The dwelling location
• Existing building locations and measurements
• Any other building locations and measurements
• The proposed garage, shed, gazebo, sun shelter, deck, above ground pool, or pool fence enclosure
• The size of the proposed work
• Front, side, and rear setbacks from lot lines
• Distances from the proposed deck or pool to existing structures
• Septic system location when it applies to the property
• The pool fence enclosure and gate location for an above ground pool
• Labels that distinguish existing items from proposed items

Detached accessory buildings

For a detached garage, shed, gazebo, sun shelter, or similar accessory building, draw the full lot and show the dwelling first. Add existing buildings and structures, then draw the proposed accessory building in its intended location.

Write the proposed building size directly on the drawing. Add the front, side, and rear setbacks from the proposed structure to the lot lines. If another building is close to the proposed location, include that building and the spacing between the two so the reviewer can understand the site layout.

City of Sarnia provides this accessory building site plan example:

Accessory site plan example in City of Sarnia

Decks

For a deck, show the property lines, the dwelling, all existing structures that matter to the project, and the septic system location if the property has one. Draw the proposed deck against the house or in the intended location, label it as proposed, and add its dimensions.

Add the distances from the proposed deck to all relevant structures, septic components, and property lines. If stairs, landings, or a change in deck shape affect the footprint, draw those parts as well so the site plan matches the rest of the deck permit drawings.

Above ground pools

For an above ground pool, start with the lot dimensions, dwelling, other buildings, and septic system location. Add the proposed swimming pool, the proposed pool fence enclosure, and the gate location.

Write the pool size on the drawing and show the setbacks from the proposed swimming pool to adjacent buildings and to the pool fence enclosure. City of Sarnia allows pool site plans to be drawn by hand, but they should be legible and drawn to scale.

(Without Survey) How to draw a site plan by hand for City of Sarnia

City of Sarnia's above ground pool application says site plans can be drawn by hand if they are legible and drawn to scale. A careful hand drawing can also be a practical starting point for simple accessory building or deck applications when you have reliable measurements.

Use a ruler, write measurements directly on the drawing, and keep the property outline large enough that the reviewer can read the labels without zooming in.

1. Draw the footprint of your house

Start with the dwelling. Draw the outside shape of the house large enough to leave room around it for property lines, existing structures, the proposed work, and measurements.

Label it "existing dwelling" or "existing house" and add the property address.

House footprint drawn by hand

2. Draw your property boundary

Draw the property boundary around the house. Use your property measurements, survey, deed plan, or other reliable lot information when you have it.

Label the front, side, and rear lot lines. If a boundary is approximate, say so on the drawing. The site plan should not leave City of Sarnia guessing which side of the lot is the front yard, side yard, or rear yard.

Property boundary drawn by hand

3. Draw the main street along your property

Draw the street along the front of the lot and write the street name. If the property is on a corner, draw and label both streets.

This helps establish the front yard and makes the drawing easier to orient during review.

Main street drawn on hand site plan

4. Label the rear of your property

Label the rear yard or back of the property. For City of Sarnia applications that ask for front, side, and rear setbacks, the yard labels make it easier to match your measurements to the permit requirements.

Rear yard labeled on hand site plan

5. Draw existing and proposed structures

Add existing buildings and structures, including the dwelling, garage, shed, deck, gazebo, sun shelter, and other buildings near the proposed work. If the property has a septic system and the permit guide asks for it, show the septic system location.

Draw the proposed work in its intended location. Label it clearly, such as "proposed shed," "proposed detached garage," "proposed deck," "proposed above ground pool," or "proposed pool fence enclosure."

Existing and proposed structures drawn by hand

6. Measure setbacks, proposed, and existing structures

Write the proposed work dimensions directly on the site plan. For an accessory building, include the location and size of the proposed garage or shed. For a deck, include the deck dimensions and the distance from the proposed deck to property lines, existing structures, and septic components. For a pool, include the pool size, pool fence enclosure or gate location, and distances to adjacent buildings and the enclosure.

Add front, side, and rear setbacks from the proposed work to the lot lines. If a measurement is approximate, label it as approximate. Keep the written dimensions dark and readable.

Measurements added to hand-drawn site plan

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(With Survey) How to draw a site plan using a survey for City of Sarnia

If you have a property survey, use it as the base for your City of Sarnia site plan. A survey can make the property lines, building locations, and setbacks more reliable than a drawing started from memory.

If you do not have a survey, check your closing documents first. You can also ask your lawyer, closing agent, title insurer, or mortgage company. If needed, City of Sarnia handles access-to-information requests under MFIPPA through its Freedom of Information process, including requests related to building permits.

If you do not have a survey, see our guide for getting a property survey in Ontario before paying for a new one.

1. Print your survey, and get an extra blank piece of paper

Print the survey at a readable size. If possible, keep the scale intact. Get a blank sheet of paper, tracing paper, or a transparent digital layer if you are working on a tablet.

Do not mark up your only original copy. Work on a copy so you can start over if needed.

Example property survey to use as the base drawing

Blank paper, ruler, and pen for drawing over a survey

2. Place the paper over, and trace important details

Trace the property boundary, dwelling, street, and any existing buildings or structures that affect the project. Carry over the survey measurements that help you calculate the front, side, and rear setbacks.

If the survey shows septic components, easements, rights, drainage features, or other site constraints that affect the proposed location, include the relevant parts on your site plan.

Survey details traced by hand

3. Draw your proposed structures and add measurements and setbacks

Draw the proposed accessory building, deck, above ground pool, pool fence enclosure, or other work on the survey copy. Label the proposed item clearly and write its dimensions on the drawing.

Add the setbacks from the proposed work to the closest lot lines. For decks and pools, also add distances to adjacent buildings, structures, septic components, and the pool fence enclosure when those items apply. If the survey has a scale, use it to place the proposed work accurately, then rely on written measurements to make the permit review clear.

Proposed structures drawn on traced survey

Site plan examples for permit for City of Sarnia

For City of Sarnia, a strong site plan example is simple, readable, and measurement-heavy. The accessory building example shows the kind of information homeowners should aim to provide: the property outline, dwelling, proposed accessory building, existing structures, and setbacks.

For a deck, the same idea applies, but the drawing should focus on the proposed deck's relationship to the house, structures, septic system, and property lines. For an above ground pool, the site plan should make the pool, pool fence enclosure, gate, adjacent buildings, and septic location easy to identify.

Your drawing does not need to look like a professional architectural sheet for every small project. It needs to be legible, drawn to scale when required, labeled, and specific enough for City of Sarnia to verify the proposed location.

Common site plan mistakes that delay your building permit in City of Sarnia

Missing property measurements or lot dimensions

Do not draw only the house and the proposed work. Include the property measurements or lot dimensions so City of Sarnia can understand the available space and review the setbacks.

Missing front, side, and rear setbacks

City of Sarnia's accessory building guide asks for front, side, and rear setbacks from lot lines. Write those measurements on the drawing, especially for sheds, garages, gazebos, sun shelters, decks, pools, and fence enclosures.

Leaving out existing buildings or septic information

Show the dwelling and other buildings on the lot. For decks and pools, include the septic system location when it applies. Missing septic or existing-structure information can make the reviewer ask for a revised site plan.

Not enough detail about the proposed work

Label the proposed structure or work area and write its size. A rectangle without dimensions does not tell the reviewer whether it is a shed, garage, deck, pool, or fence enclosure. Keep the site plan consistent with the rest of the permit drawings and application forms.

Frequently asked questions about site plans

Can homeowners prepare and submit their own drawings in City of Sarnia?

Yes. In Ontario, homeowners can generally prepare drawings for a house they own because the Ontario Building Code exempts design work for "a house owned by the person" from the usual designer qualification requirements under Division C, Article 3.2.5.1.(3)(b)(i). City of Sarnia can still require drawings that are legible, scaled or dimensioned, and complete enough for permit review.

What if City of Sarnia asks me to fill out a Schedule 1: Designer Information form?

For homeowner-prepared drawings in Ontario, select House for the design activities and describe the project, such as "deck," "shed," "detached garage," "gazebo," "sun shelter," or "above ground pool."

Under the designer declaration, choose the option stating that the design work is exempt from the registration and qualification requirements of the Building Code. For the basis of exemption, enter Homeowner.

Where can I get a legal property survey in City of Sarnia?

Start with the records from when you bought the property. Check your closing documents and ask your lawyer, closing agent, title insurer, or mortgage company. If you need to request municipal records, City of Sarnia accepts Freedom of Information requests through its access-to-information process, including requests connected to building permits.

Read our Ontario ultimate guide for getting a property survey before ordering a new survey.

Does my survey need to be recent?

For many residential permit drawings in Ontario, an older survey by a licensed Ontario Land Surveyor can still be useful if it accurately shows the property lines and base property information. Update the site plan to show current buildings, removed structures, new structures, septic information, and the proposed work so the drawing reflects the property as it exists today.

What if City of Sarnia rejects my site plan?

Read the review comments as a checklist. Add the missing property measurements, lot dimensions, dwelling location, existing building measurements, proposed work size, front, side, or rear setbacks, septic system location, pool fence enclosure, gate location, or distances to adjacent buildings.

When you resubmit, make the revisions easy to find and keep the site plan consistent with the permit application, deck drawings, pool application, accessory building guide, or other documents in the package.

Conclusion

A good beginner site plan for City of Sarnia is clear, measured, and focused on the proposed location. Show the property, dwelling, existing structures, proposed work, septic information when it applies, and the dimensions and setbacks that matter for your residential building permit.

Create a site plan for free using HomeCat that gets your building permit approved in City of Sarnia. Get started