Plex (duplex, triplex, multiplex)

What changes with the number of units

A plex is an income property, whether or not the owner lives in it. The number of units changes some rules:

• RL-31 slips: one Relevé 31 (RL-31) per dwelling rented on December 31. With more than 5 slips, you must file online.
• First purchase: the home ownership tax credit Québec announced in April 2026 expressly covers a duplex or triplex the buyer lives in, subject to the law being passed; buildings with 4 or more units aren't addressed.
• New construction: the 100% GST rebate for purpose-built rental housing covers a building with at least 4 units, each with a private kitchen, bathroom and living area (or at least 10 units), with 90% or more held for long-term rental and construction started after September 13, 2023 and before 2031. Duplexes, triplexes and substantial renovations are excluded.
• Repossession: only an owner, not a corporation, can repossess a unit in their plex to live in it or house a close relative.

A plex's numbers

When you buy, three ratios sum up a plex: the gross rent multiplier, net operating income and the cap rate, to which the lender adds the debt service coverage ratio. The plex return calculator gives them all, and the welcome tax calculator works out the transfer duties to add to your down payment.

Learn more

• Buying

  Buying a plex in Québec: welcome tax, returns and financing

  What the welcome tax costs from one city to the next, the new first-home tax credit, the ratios that tell you whether a plex pays for itself, and how Canadian mortgages differ.