Condo

Duct Cleaning in Condos: Who's Responsible?

It's a classic question, and the answer goes beyond HVAC — it touches on condominium law. In Quebec, confusion is common because the line between private and common areas isn't always obvious — and it varies from one building to the next. Here's how to make sense of it.

The Basic Principle: Private vs. Common

In a divided co-ownership, every unit has two "zones":

• Private portions: the inside of your condo. You own it and you're responsible for it.
• Common portions: the structure, main ductwork, roofs, entryways, shared equipment. The syndicate is responsible for these.

Whether duct cleaning falls on you depends on which category the ducts fall into — and that's not always clear without reading the declaration of co-ownership.

The 3 Most Common Scenarios in Montreal

Case 1: Individual HVAC System in Each Condo

This is the most common setup in new or renovated condos. Each unit has its own furnace or heat pump, its own ducts, its own air exchanger. In this case, the unit owner is responsible for cleaning their own ducts — just as they're responsible for cleaning their carpet or replacing a faucet.

Case 2: Shared Central System for the Building

Some buildings, especially older or very high-end ones, have a central HVAC system that serves several condos. In this case, the syndicate is responsible for the main ducts (common portion), but the branches running into each unit are sometimes private. You need to read the declaration of co-ownership.

Case 3: The Mixed Case (the Most Confusing)

Many buildings have shared exhaust ventilation (bathrooms, kitchen hood) running through a collective duct, and individual fresh-air intake or heating. Here, responsibility is split: the syndicate handles the collective duct, each unit owner handles their own private portion.

How to Find Out Who Pays

Three sources to check, in this order:

1. The declaration of co-ownership — the section on private and common portions
2. The building bylaws — sometimes they specify maintenance frequency and who pays
3. Recent meeting minutes — if the topic has come up, there's often a clear decision on record

The Common Case of Dryer Vents

A small exception that's often overlooked: dryer vents. In most buildings, the duct passes through common areas but starts inside your condo. Typical responsibility breakdown:

• The unit owner pays for the cleaning
• The syndicate authorizes access to the roof or technical shaft if needed

But be careful: a dryer vent that causes a fire can trigger the unit owner's civil liability. All the more reason to clean it regularly.

Our Practical Advice

If you're a unit owner with no idea of your ducts' maintenance history, request a quote from a professional and ask the syndicate in parallel. In 9 cases out of 10, the answer is "it's on you" — and it's a good thing to settle before you're dealing with poor air quality or, worse, a claim.

If you're on the syndicate and hesitating about cleaning the common areas, know that regular maintenance is often an explicit or implicit requirement of the building's insurance. In the event of a claim, neglected maintenance can lead to a denial.