Filing a Claim for an Uninhabitable Unit, Step by Step

Before you start: what makes a unit "uninhabitable"

"Uninhabitable" isn't a single defined term in the Residential Tenancies Act, but it's generally used to describe conditions well beyond an ordinary maintenance request — a sustained loss of heat in winter, a serious pest infestation, extensive mould, structural damage, or a loss of water or electricity that makes the unit genuinely difficult or unsafe to live in. Our page on compensation for an uninhabitable unit explains the general legal basis for a claim in more depth. In practice, a claim like this is generally brought through the same T6 maintenance application used for less severe repair issues, but the severity and duration of the problem generally affect both the urgency of the situation and the size of any compensation the LTB may consider appropriate.

Before anything else, think honestly about whether the unit is safe to remain in short-term. Nothing here is a substitute for emergency action — if there's an immediate danger such as a gas leak, fire hazard, or structural collapse risk, contact emergency services or your municipality's building or fire department right away rather than waiting on any LTB process.

Once any immediate danger has been addressed, it's worth thinking about the problem in terms of both severity and duration, since both generally factor into how the LTB assesses a claim like this. A short but serious disruption, such as a weekend without water, is a different kind of claim than a persistent issue that has gone unresolved for months — the evidence and the framing of your request should generally reflect which of these more closely matches your situation.

Step 1: Document the severity and duration of the problem

Because the compensation the LTB may order generally reflects how serious the problem was and how long it lasted, thorough documentation matters even more here than in an ordinary repair case:

1. Photograph and video the conditions in detail, including dates, and repeat this periodically if the problem is ongoing or worsening.
2. Keep a daily or near-daily log once conditions become severe — for example, recording indoor temperatures during a heating failure, or documenting each new area affected by mould or pests.
3. Keep receipts for anything you've had to pay for because of the condition, such as alternate accommodation, space heaters, dehumidifiers, or discarded belongings.
4. Note any health effects you or household members experienced that you believe are connected to the conditions, though be cautious about asserting a medical cause without supporting documentation.

If a problem fluctuates — mould that worsens after rain, or heat loss that's worse overnight — try to capture it at its worst as well as its typical state, since a single photo taken on a mild day can understate how serious the issue has actually been over the full period you're claiming for.

Step 2: Notify the landlord, and consider involving the municipality

Put the landlord on written notice of the problem as soon as possible, even if you've raised it verbally or informally before. Be specific about what's wrong, when it started, and that you consider the unit's habitability seriously affected. Where the landlord doesn't respond promptly, or the condition is severe, contacting your municipality's property standards or bylaw enforcement department is generally a reasonable next step — an inspection and any resulting order can become valuable supporting evidence for your LTB application, and may also prompt faster action from the landlord.

Step 3: Decide whether to stay, temporarily relocate, or move out

Whether to remain in the unit, arrange temporary accommodation, or move out entirely is a personal and sometimes difficult decision, and the right choice generally depends on the severity of the conditions, your household's circumstances, and the costs involved. A few general considerations:

1. Remaining in the unit while pursuing a claim generally does not weaken your case, and in many situations is the most practical option while repairs are pending.
2. Temporary relocation costs, where reasonable and documented, can generally be claimed as part of the compensation sought.
3. Moving out permanently is a significant step, and a tenant considering this should generally understand how it may affect their notice obligations and any ongoing claim before doing so.

Whatever you decide, avoid simply stopping rent payments as a way of responding to the conditions — this generally creates a separate risk of its own, discussed further below. It can help to think of the decision in stages rather than all at once: continuing to document the problem while you decide, keeping all communication with the landlord in writing, and revisiting the question of relocation if conditions worsen or the landlord's response remains inadequate after a reasonable period.

Step 4: File your application with the LTB

A claim over an uninhabitable unit is generally filed as a T6 application through the Tribunals Ontario Portal:

1. Create or log into your portal account and select the T6 application.
2. Enter the rental unit address and the landlord's legal name and current address.
3. Describe the conditions in detail, including when they began, their severity, and the impact on your ability to live in the unit.
4. Upload your photos, logs, written notices to the landlord, and any municipal inspection report or order.
5. Specify the compensation you're seeking, tied to the documented severity and duration of the problem and any costs incurred.
6. Submit the application and keep the confirmation number and a copy of everything filed.

What happens after you file

Once filed, the LTB will generally schedule a hearing and notify the landlord directly. At the hearing, you generally need to show, on a balance of probabilities, that the conditions existed, how serious and prolonged they were, and that the landlord had reasonable notice and an opportunity to address them. Where the conditions are found to have seriously affected your use of the unit, the LTB may order a rent abatement reflecting the reduced value of the unit during that period, along with any other appropriate remedy such as a repair deadline. Our LTB hearing guide explains the general hearing process in more depth.

Common mistakes that cause delay or rejection

A few recurring issues generally weaken a claim like this:

1. Thin or inconsistent documentation of how severe and how long-lasting the conditions actually were.
2. Stopping rent payments without an LTB order, which can expose the tenant to a separate arrears issue.
3. Waiting too long to put the landlord on written notice, or never doing so at all.
4. Asking for a lump-sum amount without a clear, itemized basis tied to the severity and duration of the problem.
5. Overlooking the value of a municipal property standards inspection or order as supporting evidence.

For severe conditions, especially anything involving a genuine safety risk, contacting your municipality's property standards department and speaking with a paralegal, lawyer, or community legal clinic alongside filing an LTB application is generally a sound additional step.

Frequently Asked Questions

Related reading

Reviewed by Ryan J. Manilla, BA, JD

Legal Reviewer · Landlord Tenant Ontario