Garage Drawings for Building Permits: Plans & Requirements
🏗️ Quick Answer
Any garage over 10 m² (108 sq ft) requires a building permit in Ottawa. Your garage drawings package must include a site plan (showing the garage position, setbacks, and lot coverage), a floor/foundation plan (footings, slab, layout), elevations (all four sides), a cross-section (foundation to roof construction), and construction details. Attached garages also require fire separation details between the garage and living space. Ottawa’s review target for garage permits is 5 business days for the first review of a complete submission.
Building a garage is one of the most common residential construction projects in Ottawa — whether it is a detached two-car garage, a single-car attached garage, or a carport with storage. Regardless of the type, if the structure exceeds 10 square metres, you need a building permit, and that permit requires a complete set of garage drawings.
At Architectural Drawing, we prepare garage drawings for detached and attached garages across Ottawa — from simple single-car structures to large multi-bay garages with workshops. This guide covers exactly what your drawing package needs to include and the zoning rules that shape your design.
Do You Need a Building Permit for a Garage in Ottawa?
The City of Ottawa uses a clear size threshold to determine whether a building permit is required for accessory buildings like garages:
⚠️ Heritage Exception: If your property is a designated heritage building or is located within a Heritage Conservation District overlay, all accessory buildings — regardless of size — require consultation with Building Code Services before starting construction. Standard exemptions do not apply. For more on permits for accessory structures, see our shed and accessory building permit guide.
Detached vs Attached Garage: Drawing Differences
Both garage types require the same core garage drawings, but attached garages add extra requirements because they share structure and envelope with the house. Here is how the drawing packages differ:
🏗️ Detached Garage
✅ Site plan with garage position and setbacks
✅ Floor plan / foundation plan
✅ All four elevations
✅ Cross-section (foundation to roof)
✅ Construction details
✅ Grading plan (if >55 m² or within 1.2 m of lot line)
🏠 Attached Garage
✅ Everything in the detached package, plus:
✅ Fire separation details (garage-to-house wall and ceiling)
✅ Self-closing fire-rated door specification
✅ Existing house floor plan (to show connection point)
✅ Updated house elevations (sides affected by the addition)
✅ Structural details if connecting to existing foundation
The fire separation between an attached garage and living space is one of the most important safety elements. The Ontario Building Code requires this separation to prevent carbon monoxide and fire from spreading into the home — and the drawings must clearly show the rating, materials, and construction method. If you need existing conditions documented first, see our as-built drawings guide.
What Your Garage Drawings Must Include
Ottawa Building Code Services requires the following information across your garage drawings package. Each item must be accurately drawn to scale, fully dimensioned, and legible:
📍 Site Plan Requirements
Show the entire property with the garage positioned on the lot. Include property boundaries and dimensions, setback distances from the garage to all lot lines, distance between the garage and the house (and any other structures), driveway and access, existing and proposed grades, overall dimensions of the garage footprint, lot coverage calculation, and a zoning compliance summary table. For full site plan requirements, see our dedicated guide.
📐 Floor Plan & Foundation Plan
Show the interior layout including vehicle bay dimensions, storage areas, door locations and widths (vehicle door and person door), window locations and sizes, foundation wall type and thickness, strip footing sizes, slab thickness and reinforcement, column footing sizes and locations (if applicable), beam and joist sizes and spacing, plumbing fixtures (if heated garage with floor drain), and electrical panel location. For garages with living space or workshops above, a second-floor plan is also required. See our floor plan guide for detailed requirements.
🏠 Elevations (All Four Sides)
Show the exterior from each side including overall building height (from average grade to peak), roof pitch, eave and soffit lines, vehicle door size and style (overhead sectional, swing-out, etc.), person door and window locations, cladding materials, existing and proposed grade lines, and limiting distance to property lines. For more on what elevation drawings must show, see our dedicated guide.
✂️ Cross-Section (Foundation to Roof)
At least one section cut through the garage showing footing depth below grade (minimum frost depth for Ottawa), foundation wall construction, slab-on-grade assembly, wall framing (stud size, height), roof structure (trusses or rafters with sizes and spacing), insulation values (if heated garage), ceiling height, and material callouts for every layer of the assembly.
🔧 Construction Details
Enlarged drawings of specific assemblies: typical wall section, eave/soffit detail, foundation-to-wall connection, garage door header sizing, person door framing, and (for attached garages) the fire separation wall/ceiling assembly with material specifications. If pre-engineered trusses are used, the manufacturer’s sealed truss design drawings must be included.
Need Garage Drawings for an Ottawa Permit?
We prepare complete garage permit packages — site plan, floor plan, elevations, sections, and all details — ready for City submission.
(613) 518-1387
Ottawa Zoning Rules That Shape Your Garage Design
Before your garage drawings are prepared, zoning compliance must be confirmed. The Ottawa zoning bylaw imposes specific rules on accessory buildings that directly affect the design:
Your specific zone may have different numbers — a Development Information Officer (DIO) at Building Code Services can confirm the exact requirements for your property. If your garage design does not comply with the zoning bylaw, you may need a minor variance from the Committee of Adjustment before the building permit can be issued. This adds time and cost, so confirming zoning early is important.
Garage Drawing Costs & Permit Timeline
The 5-business-day target applies to the first review of a complete submission. Incomplete drawings will be returned for corrections before the review clock even starts. For a full breakdown of permit fees and permit timelines, see our dedicated guides. For pricing on all drawing types, see our drawing costs guide.
Required Inspections for Garage Construction
Once your garage permit is issued, building inspections are required at key construction stages. The inspector compares on-site work against your approved garage drawings:
Inspections must be booked 48 hours in advance. The approved drawings and building permit must be on site for every inspection. Failure to book required inspections — or having work that does not match the drawings — can result in orders to uncover and redo work.
Frequently Asked Questions
Can I draw my own garage plans for a building permit?
Yes. Ontario’s homeowner exemption allows you to prepare your own drawings for a garage that serves a house you own. However, the drawings must still be drawn to scale, fully dimensioned, and meet all City requirements for completeness. If the drawings are incomplete or inaccurate, they will be returned — which is why most homeowners hire a professional to save time and avoid deficiency cycles.
What size garage can I build without a permit in Ottawa?
An accessory building (including a garage) that is 10 square metres (108 sq ft) or less does not require a building permit. For storage sheds only, the exemption extends to 15 square metres (161 sq ft) if the shed is one storey, has no plumbing, and is ancillary to the principal dwelling. Keep in mind that even exempt structures must still comply with the zoning bylaw (setbacks, height, lot coverage) and the Ontario Building Code.
Do I need a grading plan for my garage?
A grading plan is required if the garage footprint exceeds 55 square metres (592 sq ft) or if any part of the structure is within 1.2 metres (4 ft) of a property line. For smaller garages set well away from lot lines, grading information may only need to appear on the site plan. However, Ottawa Building Code Services may request a separate grading plan if the lot has complex drainage conditions.
Can I build a second storey or loft above my garage?
Potentially, but this significantly increases zoning and code requirements. A second storey or habitable loft adds to the building height (which must still comply with the zoning bylaw maximum) and may require structural engineering for the floor system. If the loft space is intended for habitation — such as a home office or guest suite — it must meet the Ontario Building Code for living spaces including egress, fire safety, and insulation. Your garage drawings must show the second floor plan, stair design, and updated cross-sections.
What fire separation is required between an attached garage and the house?
The Ontario Building Code requires a fire separation between the garage and any living space. The common wall and ceiling between the garage and the house must have a fire-resistance rating — typically achieved with 12.7 mm (½”) Type X gypsum board on the garage side of walls and ceiling. The door between the garage and the house must be at least a solid-core wood or metal door with a self-closing device. These details must be clearly shown on your garage drawings.
Do I need a survey for a garage permit?
A full survey by an Ontario Land Surveyor is not always required, but it is strongly recommended — especially if the garage is close to property lines. The City needs accurate setback dimensions, and if there is any dispute or uncertainty about property boundaries, the building official may request a survey before issuing the permit. If you have an existing survey, it can be used as the base for your site plan.
Do I need separate electrical and plumbing permits for a garage?
Electrical permits are handled separately through the Electrical Safety Authority (ESA), not the City of Ottawa. If your garage will have electrical service, lighting, or outlets, you need an ESA permit and a licensed electrician. Plumbing work (e.g., a floor drain, hose bib, or wash sink) requires a separate plumbing permit from the City.
Can I use stock garage plans from the internet?
Stock plans cannot be submitted directly for a building permit. They must be adapted by a qualified designer to reflect your specific property dimensions, Ottawa zoning requirements, local soil and frost depth conditions, and Ontario Building Code compliance. A stock plan is a starting point for design — not a permit-ready document. For more on this, see our floor plan drawings guide.
What are the typical drawing types needed for a garage permit?
A standard detached garage permit package includes 5 drawing types: site plan, floor/foundation plan, all four elevations, at least one cross-section, and construction details. Attached garages add fire separation details and existing house plans. For a complete overview of all types of architectural drawings for building permits, see our hub guide.
What happens if I build a garage without a permit?
Building without a required permit can result in a stop-work order, fines up to $50,000 for a first offence under the Building Code Act, and an order to demolish the unpermitted structure. Even if you avoid enforcement during construction, an unpermitted garage creates serious problems when selling your home — title searches and home inspections will flag the missing permit. Retroactive permits are possible but typically cost more and may require opening up completed work for inspection. See our guide on what renovations need a building permit for more details.
Get Your Garage Permit Drawings
Complete drawing packages for detached and attached garages — designed to Ottawa standards and ready for City submission.
(613) 518-1387