How much does second-storey addition cost?

With Zigma Group, second-storey addition starts from $260 per sq ft. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are floor area being added; reinforcement the existing structure needs; and number of bathrooms and finish level upstairs.

Can a second storey be added to any bungalow?

Most can, but it depends on the foundation and wall structure. An engineer assesses it, and reinforcement is added where needed.

Do I have to move out for a second-storey addition?

Yes, for the main structural phase, because the roof is removed and services are disconnected at times.

Where does the staircase go?

The stair takes real floor area on both levels, so its position is one of the first design decisions. We usually place it where it disturbs the main-floor layout least.

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Second-Storey Addition

More space · Greater Toronto Area

Second-Storey Additions in the GTA

Adding a second storey can double the size of a bungalow without using any of the yard. The existing house has to be able to carry it, so the work starts with the structure.

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Tall brick house with a narrow corner window seen from the street — From our Damavand project

Scope

What is included.

Structural assessment of foundation and walls
Design, engineering and permit drawings
Zoning review and variance applications where needed
Roof removal and new floor framing
New stair, bedrooms and bathrooms
Exterior cladding and roofing to unify the house

Cost

What it costs.

From $260per sq ft

What moves the price

Floor area being added
Reinforcement the existing structure needs
Number of bathrooms and finish level upstairs

Prices are in Canadian dollars before HST, as of October 2026. Every project is confirmed with a written quote after a site visit.

Before you start

What to know.

Can the house carry it?
An engineer checks whether the foundation and walls can support another floor. Some houses need reinforcing first, and that changes the budget.
Permits and zoning
A second storey needs a building permit and must meet height and floor-area limits. Older neighbourhoods often have rules meant to keep new upper floors in scale with the street.
Moving out
The roof comes off, so the house is not liveable during the main structural phase. We plan the sequence to keep that period as short as the work allows.

How we work

One team for every stage.

AssessWe survey the house as it stands.
Design and permitsDrawings and approvals before work starts.
Strip-outWhat is worn out comes off.
RebuildStructure, wiring, plumbing and walls.
FinishesCabinetry, tile, floors and paint.
HandoverWalkthrough and documents.

Questions

Second-Storey Addition: the short answers.

How much does second-storey addition cost?: With Zigma Group, second-storey addition starts from $260 per sq ft. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are floor area being added; reinforcement the existing structure needs; and number of bathrooms and finish level upstairs.
Can a second storey be added to any bungalow?: Most can, but it depends on the foundation and wall structure. An engineer assesses it, and reinforcement is added where needed.
Do I have to move out for a second-storey addition?: Yes, for the main structural phase, because the roof is removed and services are disconnected at times.
Where does the staircase go?: The stair takes real floor area on both levels, so its position is one of the first design decisions. We usually place it where it disturbs the main-floor layout least.

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