What are typical demolition costs when opening up a wall for an addition in Ottawa?

Opening an existing exterior wall to connect your home to a new addition is more involved than it looks. As broad perspective only, the demolition and structural work for the opening can range from roughly $3,000 to $15,000, depending on whether the wall is load-bearing, what runs through it and how wide the opening is. Treat that as perspective, not a quote.

The first, non-negotiable step is determining whether the wall is load-bearing. Exterior walls usually carry the floor and roof above, so expect that yours does. A structural engineer or designer specifies the beam, its supports and how the load gets down to the foundation. The City's permit list includes "Structural repairs or alterations", so plan on this being part of your addition's permit drawings, and the inspector will want to see the beam installed as designed.

The main cost drivers:

• The beam. Steel or engineered lumber, depending on span, load and headroom. Steel can be shallower for the same load, which helps where ceiling height is tight. The beam needs proper bearing at each end, often with new posts carrying load down to the foundation.
• Temporary shoring. While the old wall comes out and the new beam goes in, the structure above must be supported. Ask your contractor how they will shore it and who designed the shoring if the span is large.
• Services in the wall. Wiring, plumbing, ductwork or gas lines may need rerouting. Electrical work needs an ESA notification and an ESA-licensed electrical contractor; plumbers are a compulsory trade; gas work is done by a TSSA-certified gas technician. Identify these during planning, not during demolition.
• Demolition and disposal. Cutting, removing and hauling away drywall, plaster, framing, sheathing and cladding, plus bin rental.
• Finishing. Patching floors, ceilings and walls around the new opening so it looks original.

Older homes deserve one more step. Some older building materials, such as certain joint compounds, plaster, insulation and floor tiles, may contain asbestos. Ask your contractor about testing suspect materials before demolition, and if anything tests positive, have it handled by an abatement contractor before work proceeds.

When comparing quotes, ask each contractor to separate the engineered beam and shoring from demolition, service rerouting and finishing, so you can see where the cost lies. You can browse addition contractors in the Ottawa Construction Network directory at justynrookcontracting.com and compare.

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Looking for experienced contractors? The Ottawa Construction Network connects homeowners with qualified professionals:

• Justyn Rook Contracting
• JC Carpentry
• Dump n Dash Hauling
• Home Front Services
• MAK Construction and Development Inc

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