Why You Need a Permit

Ontario law requires a building permit for any basement apartment. An unpermitted unit creates serious liability — it cannot legally be rented, affects your insurance, and may need to be removed if discovered during a home sale or inspection.

A permitted basement apartment, on the other hand, is a legal asset that adds measurable value to your property.

What the Permit Covers

A basement secondary unit permit application typically requires drawings and compliance documentation for:

• Fire separation — a minimum 30-minute fire-rated assembly between the unit and the rest of the house
• Egress — a window or door that meets minimum size requirements for emergency escape
• Structural modifications — any walls moved, beams added, or openings created must be shown in P.Eng-stamped drawings
• Separate entrance — if a separate entrance is added or modified, it requires its own structural and architectural details
• HVAC and plumbing — the unit needs its own heating and ventilation, and any new plumbing must be permitted

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What Makes a Wall Load-Bearing?

A load-bearing wall is one that carries structural loads from above — floor joists, roof rafters, or other walls — and transfers them down to the foundation. Removing one without proper engineering means those loads have nowhere to go, which can cause serious structural problems.

Common signs a wall may be load-bearing include:

• The wall runs perpendicular to the floor joists above
• It sits directly above the foundation wall or a beam in the basement
• There is a wall directly above it on the next floor
• The wall is near the centre of the house and runs parallel to the ridge of the roof

What Happens When You Remove a Load-Bearing Wall

When a load-bearing wall is removed, the loads it was carrying must be redirected. This is done by installing a properly engineered beam in its place, supported by posts at each end, which carry the load down to the foundation.

A structural engineer sizes the beam and posts based on the actual loads involved — not a general rule of thumb. Undersized beams can deflect, crack drywall, and eventually fail. Oversized beams waste money and headroom. Proper engineering gets it right the first time.

The Permit Process

Load-bearing wall removal requires a building permit in Ontario. The permit application must include P.Eng-stamped structural drawings showing the beam, posts, and any modifications to the foundation. We prepare this complete package for homeowners across the GTA.

Home Additions

A home addition extends your existing house — adding square footage to the ground floor, building up with a second storey, or enclosing a garage or covered area. Additions require a building permit and must comply with Ontario Building Code and local zoning setbacks.

From a structural standpoint, additions need to connect cleanly to the existing structure. This means engineering the new foundation, floor system, and roof tie-in to work with what’s already there — not just sitting beside it.

Garden Suites

A garden suite is a self-contained dwelling unit built in the rear yard of a property that already has a house on it. Ontario’s More Homes Built Faster Act made garden suites a permitted use in most residential zones across the province.

Garden suites require their own full structural package — foundation design, framing, and connection to services. They are subject to site-specific zoning rules around setbacks, height, and lot coverage.

Which Is Right for Your Project?

The right choice depends on your goals, lot configuration, zoning rules, and budget. An addition is typically faster to permit if your lot coverage allows it. A garden suite adds a separate unit that can be rented or used for family — but involves more complex site planning and servicing.

We can help you understand the structural requirements for either option. Contact us to discuss your specific project.

The Core Drawing Package

Most residential building permit applications in Ontario require the following:

• Site plan — showing the property boundaries, existing structure, and proposed work in relation to the lot
• Floor plans — existing and proposed, drawn to scale, showing all rooms, walls, windows, and doors
• Structural drawings — P.Eng-stamped drawings showing beam sizes, post locations, footing dimensions, and framing details
• Elevations — showing what the building will look like from each exterior side
• Cross-sections — a cut-through view showing floor-to-ceiling heights, insulation, and construction assembly

What We Prepare

At GranDesign Engineering, we focus on the structural drawings — the component that most directly determines whether your permit application is approved without revisions. We prepare complete structural packages including:

• Beam and column sizing with load calculations
• Foundation and footing design
• Floor and roof framing layouts
• Shoring and temporary support notes for wall removals
• Municipal comment response and revision support

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When Ontario Building Code Requires a P.Eng

The Ontario Building Code does not always mandate a Professional Engineer — but many projects do require one, and municipalities can request P.Eng-stamped drawings even when the Code does not explicitly require it.

You will almost always need P.Eng-stamped structural drawings for:

• Home additions that affect the load path of the existing structure
• Load-bearing wall removal or structural openings
• Basement secondary unit (apartment) permits that include structural modifications
• New custom home construction requiring engineered foundations and framing
• Commercial renovations, change-of-use applications, and mezzanine installations
• Deck structures above a certain height or complexity

What a Structural Engineer Actually Does

A licensed P.Eng reviews the full load path of your structure — from the roof down through the walls, floors, beams, columns, and foundation. They size beams to carry the loads, design footings for any new columns, and verify that the existing structure can handle the added demand.

The result is a set of stamped drawings that tells the building inspector exactly how the work will be done — and confirms that a qualified professional has verified it will be safe.

Our Services

We prepare P.Eng-stamped structural drawings for all of the most common residential and commercial permit applications across the GTA.