What Section 11 covers
Section 11 imposes a duty on landlords to keep in repair and proper working order: the structure and exterior (roof, walls, windows, doors, drains, gutters, external pipes); installations for supply of water, gas, electricity, and sanitation; installations for space heating and water heating. 'Keep in repair' means maintaining the property to the standard it was in at the start of the tenancy.
What Section 11 doesn't cover
Section 11 doesn't require you to fix what the tenant broke, damaged through negligence, or failed to report. It also doesn't cover decorations or cosmetic condition unless they're so deteriorated that they affect the habitability of the property. Tenant improvements or alterations also fall outside Section 11.
Notice requirement
You're only obligated to repair something you've been notified about. A tenant reporting a repair triggers your duty; if they never told you, you're not liable. This is why a paper trail for repair reports matters — it establishes both when you were notified and what action you took.
Enforcement
Tenants can apply to the First-tier Tribunal for a Rent Repayment Order if you fail to maintain the property. Local authorities can issue improvement notices and, in serious cases, carry out works themselves and recover costs from you. Courts can award damages for discomfort, inconvenience, and health impacts.