Weathertightness (leaky building)

Weathertightness refers to a building's ability to keep water out. A "leaky building" is one where water ingress has caused damage to the structure, typically through cladding, joinery or flashing failures.

The background

New Zealand's leaky building crisis affected a large number of properties built roughly between the mid-1990s and mid-2000s, associated with monolithic cladding systems, untreated timber framing, minimal eaves, and certain construction details.

The risk indicators

• Built approximately 1994–2005
• Monolithic cladding — plaster, texture-coated fibre cement, EIFS
• Minimal or no eaves
• Complex rooflines, internal gutters, parapets
• Enclosed decks and balconies above living spaces
• Multi-level with flat or low-pitch roof junctions

None of these individually mean a building leaks. Together they raise the probability enough to warrant specialist investigation.

Why it matters so much

Remediation is frequently very expensive — often a full reclad. Insurance generally excludes gradual damage, and the historical claims pathways have largely closed. Lenders are cautious about affected properties, and resale is difficult.

Common misunderstanding

A standard builder's report may not detect it. Non-invasive moisture testing can miss damage inside walls. Where the risk indicators are present, commission a weathertightness specialist, not a general inspection.

Apartment buildings carry collective risk. A reclad decision by a body corporate can produce a special levy of six figures per unit. Check body corporate minutes and long-term maintenance plans carefully.

Related terms

Last reviewed: 1 August 2026 · General information only, not legal advice.

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