Compare addition types before committing to an area
A need for space may lead to a rear or side addition, another storey or internal reorganization. None is presumed authorized at a particular address. Compare effects on existing rooms, the site, access and technical checks rather than only hoped-for square metres.
Fictional example: adding rear dining space may alter garden access and daylight in a retained room; another storey may retain more outdoor space while raising different structural and stair questions. This comparison prepares a study. It does not establish that an option is cheaper, faster or feasible without building-specific information.
| Option | Effect to compare | Checks to define |
|---|---|---|
| Rear addition | Garden connection, daylight and retained-room circulation. | Siting, openings, boundaries and connections to existing work. |
| Side addition | Site access and relationship to current rooms. | Available width, setbacks and affected access. |
| Another storey | Stair, distribution and massing effect. | Height provisions, structure and work on existing construction. |
| Reorganization | Functional gain without the same added volume. | Current layout, walls and technical constraints. |
In Montréal: connect each drawing to the proposed work
For an extension, the city describes floor, elevation and site drawings, along with the applicable technical documents. The list depends on the borough and building. The file needs to show what exists and what changes; an atmosphere drawing alone does not serve that purpose.
Before commissioning documents, identify the type of work and confirm the municipal checklist. The scope then identifies the architectural drawings to produce and the involvement of other professionals.
Three ways to add, three different questions
The type of addition determines what has to be checked first: the relationship with the yard, integration with the existing massing, structural questions and the rules applying to the address.
- Rear extension: connect new living spaces to the existing rooms and the yard
- Second storey: review the existing building, structural questions and how the new level fits
- Side addition: measure the available space and the connection to the building
- Complementary volume: clarify the use before drawing (garage, studio)
Where the studio's work begins
When potential is uncertain, a feasibility study comes before design: it frames the options, the zoning and the questions to resolve, and supports deciding to proceed, adjust or drop a direction.
When the project is clear, the mandate moves into design: extension drawings, architectural integration, structural coordination, then preparation of documents for the municipality where a submission is planned.
At each stage the quote states what is delivered and which decisions are expected from you; new information can change an option that is already drawn.
Preparing the first conversation
These items help ask the right questions from the outset; they do not prejudge the municipal decision.
- Building address and municipality or borough
- Photos of the house and the area you want to extend
- Existing drawings and certificate of location, if available
- Rooms or space you want to add
- Indicative construction budget and desired timeline
- Municipal correspondence or a previous permit application
Structure, municipality and processes
An addition often affects the structure: engineering is a service separate from architectural design. The quote names the required professionals and what each of them produces.
In Montreal, extending a building requires a permit; requirements vary by borough and some projects also need a design integration review (PIIA). Confirm the process that applies to your address before starting work.
Fees, construction budget and municipal fees
Architectural fees, engineering drawings, municipal fees and construction are separate items. Their presence in the overall budget does not mean that a single quote covers them.
The quote must state the deliverables, the included revisions and the exclusions — for example what belongs to engineering, the site or the municipality — before the work begins.
Schedule: design and municipality
Design time depends on the options chosen, the available records and the decisions to make; it is defined when the mandate is accepted.
The municipality processes the application on its own schedule. Share your deadline at the first conversation to discuss a realistic scenario: no municipal timeline is promised or guaranteed.
Questions and answers
Can I build over the entire available yard?
Visible yard area is not established buildable area. Check applicable siting, setback, site coverage and landscaping provisions along with documented site constraints. An available location certificate and existing drawings help prepare those checks; they do not replace project analysis.
Should I request construction prices before drawings?
An initial budget discussion can guide options, but record its assumptions and supporting documents. Comparing contractors requires comparable scope, quantities and exclusions. An estimate based on a broad idea and a price based on detailed documents answer different questions.