Do you need a permit for a deck or balcony in Dorval?

The rules, in short

Rules from Chapter 7 (Residential neighbourhood zones H) of By-law RCM-60A-2015. The consolidation does not print section numbers, so sections are cited by their heading, except sections 336 and 356, which the text names. Setbacks come from each zone's grid of uses and standards.

• Ground-floor gallery or front steps: may project 1.55 m into the front setback (3 m² at most) and 3 m into the rear setback. (ch. 7, s. 356, table, rows 5 and 6)
• Balcony of a 1- to 3-unit house: no projection into the setbacks. (ch. 7, s. 356, table, row 10)
• Pergola, gazebo or garden pavilion: rear yard only; 2.1 m from the rear and side lines; at most 3.7 m high and 19 m². (ch. 7, s. 356, table, rows 16 and 17)
• A permit is required to build a gallery or a balcony or to add a pergola. (City page on permit and certificate applications)

Summary by Radar Foncier, in our own words: the official French text of the by-law, linked above, prevails.

Applying in Dorval

• Processing time: 30 working days after a complete application is filed
• Urban planning department: 514 633-4084
• Permits on the municipality's website