Do You Need a Structural Engineer to Remove a Wall?

For most load-bearing wall removals in Ontario, yes: you need a structural engineer, or at least a design that meets the same standard. The building department will want drawings showing the new beam, posts, connections and footings before it issues a permit. The 2024 Ontario Building Code's Part 9 tables only cover simple beams carrying uniform floor loads, and most wall removals put point loads on the beam, which takes the design into Part 4 of the code. In practice, that's an engineer's job.

There are cases where a qualified designer can do it, and cases where the wall turns out not to be load-bearing at all. Here's how to tell, and what to expect from the engineer.

Why load-bearing walls need a design

A load-bearing wall holds up something above it: floor joists, a beam, the end of another wall or a roof. Take the wall out and that load has to go somewhere. The replacement is usually a beam across the opening, with posts at each end carrying the load down through the floors to footings in the basement.

Every part of that path has to be checked:

• What the wall carries. Joists from one side or both, a second floor, a roof, or point loads from posts or walls above.
• The beam. Size, material (steel, LVL or wood) and whether it can be flush with the ceiling or must hang below.
• The posts. Size and how they're fastened at each end.
• Everything below the posts. The floor framing, the basement beam or wall, and the footing that ends up carrying the new point load.

Removing a load-bearing wall also requires a building permit in Ontario municipalities, and the permit application needs drawings that show all of this. See our guide to permits for load-bearing wall removal in the GTA.

When an engineer is required and when it isn't

The Ontario code gives three routes for structural design in houses. Under Article 9.4.1.1., structural members and connections must either conform to the prescriptive rules in Part 9, follow good engineering practice such as the Canadian Wood Council's engineering guide for wood frame construction, or be designed under Part 4.

When the Part 9 tables can work

The Part 9 span tables cover simple situations. For example, Table 9.23.4.3. gives maximum spans for steel beams supporting floors in dwelling units, based on the supported joist length and whether one or two storeys are supported. Its explanatory note lists the assumptions behind it: simply supported spans, a laterally supported top flange, 350 MPa steel, an L/360 deflection limit and uniform residential floor loads.

A wall removal can sometimes be done from tables like these when:

• The wall carries only floor joists, bearing evenly along its length
• There are no posts, walls or roof loads landing on the wall from above
• The span and supported joist length are within the table
• The posts and footings below can be shown to meet Part 9 as well

When it needs an engineer

Most real wall removals fall outside the tables because of one or more of these:

• Point loads. A post, a beam end, a girder truss or an upper wall bearing on the wall.
• Roof loads. Bearing walls in bungalows often carry ceiling joists and sometimes roof framing.
• Flush beams. Hanging joists off the side of a beam changes the connections and the beam's lateral support.
• Long spans beyond what the tables list.
• Unknown conditions below. No visible footing under the new posts, an undersized basement beam, or posts landing between existing supports.

Each of these needs a design under Part 4, and the code's Part 4 load and resistance rules are what structural engineers work with. Our guide to alternatives to a beam when removing a load-bearing wall covers what else the engineer may consider.

Engineer, designer or homeowner: who can prepare the drawings

Division C, Part 3 of the Ontario Building Code sets out who may do design work for a permit:

• Professional engineers and architects can design under their professional licences.
• Registered designers must hold a Building Code Identification Number (BCIN) in the right category and work within that qualification.
• Homeowners are exempt from the designer qualification requirements for their own house.

The homeowner exemption is about paperwork, not engineering. The building department still reviews the design against the code, and a beam carrying point loads still has to be designed properly. A BCIN designer can often prepare the overall permit drawings and coordinate with an engineer who designs the beam, posts and footings. An engineer who takes responsibility for the structural design signs and seals it, as Ontario's engineering regulations require.

What the structural engineer will do

The scope varies, but a typical wall removal engagement includes:

1. Site visit. The engineer looks at the wall, the framing above and below, and the basement. They may ask for a small section of ceiling or floor to be opened so the joists and any hidden posts can be seen.
2. Load path check. Tracing the load from the roof down to the footings, and confirming what the wall actually carries.
3. Beam and post design. Selecting the beam (steel, LVL or wood), sizing posts, and specifying bearing lengths and connections.
4. Foundation check. Deciding whether existing footings can take the new point loads or whether new footings are needed in the basement.
5. Drawings. Sealed drawings or a sealed letter with sketches for the permit, showing the members, connections, bearing and any new footings.
6. Temporary support notes. Many engineers note how the floor above must be shored during the work, though the shoring itself is the contractor's responsibility.
7. Site review (optional). Some engineers will inspect the beam and posts once installed. If you want this, ask for it up front.

The cost of engineering varies with the complexity of the job; our guide to load-bearing wall removal cost explains what drives each part of the budget.

What to have ready for the engineer

You'll save time and repeat visits if you have:

• Floor plans or rough measured sketches of each level, including the basement
• Original house drawings, if you have them, even old ones
• Photos of the wall, the ceiling above it and the basement beam and posts below it
• Your goal: the opening width you want, whether the beam must be flush with the ceiling, and any ductwork or plumbing in the wall
• Your contractor's input on access, especially how a beam would get into the house

Mention early if you'd prefer steel. A steel beam can often be shallower than an LVL for the same load, which matters for flush beams and low ceilings. Our comparison of steel beam vs LVL strength and depth explains the tradeoffs.

From the engineer's drawing to the steel

Once the design is approved, the steel has to match it exactly: the section, the length, the bearing plates, the post plates and any bolt holes. That's where shop drawings come in. A fabricator takes the engineer's design and details every piece so it fits the house on the first try. See what to send when requesting a steel beam quote for the list.

We prepare shop drawings in-house, fabricate beams and posts with plates and connections ready to install, and supply and install basement beams and posts. Engineering services are also available for projects that need them; tell us about your wall when you request a quote. Our services page covers the full process from drawings to delivery.