1. Feasibility and zoning
Start with what your lot allows: setbacks from property lines, maximum height, lot coverage and floor area. If the addition doesn’t fit, a minor variance through the municipality’s committee of adjustment may be possible, but it adds time. A current survey helps.
2. Structure and existing conditions
A second storey depends on whether the existing foundation and walls can carry the load. A rear addition needs new footings and foundations that tie in properly with the house. We assess this early so the design is buildable.
3. Design and engineering
Drawings cover the site plan, floor plans, elevations and sections. Structural design covers beams, framing, foundations and connections to the existing house. This is also when you make the decisions that drive cost: size, rooflines, windows and finishes.
4. Permits
Additions need a building permit. The municipality reviews the drawings and may ask for revisions. Properties near the escarpment, creeks or valleys may need conservation authority approval as well. See do I need a building permit?
5. Construction
- Site preparation and excavation
- Footings and foundation, with inspection
- Framing and roof, then tie-in to the existing house
- Windows, doors and exterior finishes
- Plumbing, electrical and HVAC rough-ins, with inspections
- Insulation, drywall and interior finishes
- Final inspection
Living at home during the work
Many owners stay in the house during a rear addition, because the house is only opened up for the tie-in near the end. A second storey is more disruptive. We plan the sequence with you so you know what to expect.
Where additions stall
- Designing before checking zoning
- Underestimating foundation or structural work
- Late changes after the permit is issued
- Unclear allowances for finishes
How we work
We can take an addition from feasibility through drawings, permits and construction, with one point of contact, or start with a drawing package as a first phase. See property extensions and our portfolio.