If the building does not have a cavity, the building will have leaking problem sooner or later. Is that correct?

Of course, not.

Even under current NZ Building Code and related building standards, as long as design risk is low enough (simple plan and form, within low wind zone, single story, wide eave and etc), a building’s exterior wall cladding can still be installed without cavity.

Looking at the whole NZ building history, majority of buildings were built without cladding cavity. Most of those building have been well performed without suffering major weathertightness issues.

Looking at buildings built during so called “leaky building era”, i.e. during 1995-2004, not all buildings built without cladding cavity suffered weathertightness issues. in fact, most buildings built without cladding cavity have been well performed.

Solutions for solving leaky building issues have never been only limited to providing cladding cavity only. Every single recladding project will not just involve providing cladding cavity, but also incorporate some redesign of inadequate details, rectification of defective structural details, repair of non-weathertightness related defects, make good to poor workmanship and etc.

From building inspection point of view, cladding cavity has never been a major factor for us to determine if a building is “leaky”. If we are satisfied in terms of design, construction, workmanship, maintenance and etc for a building, we will regard the building as “weathertight” regardless it contains a cavity or not.