Weathertightness problems in New Zealand housing are not ancient history. Many homes built from the late 1980s to the mid-2000s were designed and constructed in ways that let water in and gave it no easy way out, and a good number of them still change hands regularly, some fully repaired, some partly repaired and some untouched.
The causes were a combination of factors rather than a single mistake. Monolithic claddings, such as plaster systems and flush-finished fibre-cement sheet, were often fixed directly to the framing with no drained cavity behind them. Designs grew more complex, with flat roofs, parapets, internal gutters, recessed windows and decks built over living areas. Eaves shrank or disappeared altogether. At the same time, untreated or lightly treated kiln-dried timber came into wide use for framing, and that timber tolerates moisture far less well than what had been used before. Once water found its way past the cladding, it soaked into the frame and stayed there, and decay could progress for years with little visible sign inside.
Not every house from that period leaks, and not every plaster-clad home is a problem. Plenty were built carefully, have been well maintained, or have since been reclad over a cavity with new framing where it was needed. The difficulty for a buyer is that the outside of a house can look immaculate while the timber behind it is in poor condition. Fresh paint, new carpet and a tidy garden reveal nothing about the moisture content of the bottom plate under a window.
Some clues do show through for those who know where to look. Swollen or stained skirting boards, carpet that feels damp or smells musty along an exterior wall, fine cracks running from the corners of windows, sagging deck boards and black mould on internal linings can all hint at moisture where it should not be. Equally, a lack of visible signs proves very little. Framing can decay well before anything shows on the surface.
That is why assessments of houses from this era tend to go further than a standard walk-through. Inspectors look closely at the junctions where water is most likely to enter: around windows and doors, where decks meet walls, at the ends of parapets and balustrades, where the cladding meets the ground and around pipe or vent penetrations. Non-invasive meters can scan internal linings for high readings. Invasive testing, which involves drilling small holes through the cladding to take readings directly from the framing, gives more definitive information but needs the vendor’s permission, and the holes have to be sealed afterwards.
Paperwork matters as much as the physical check. Council records may show whether a house was reclad, whether that work received a code compliance certificate, or whether a weathertightness claim was ever lodged. A house that has been properly remediated, with consents and final sign-off, can be a sound purchase. One with partial repairs and no documentation carries more uncertainty, particularly at resale or when arranging insurance.
Buyers looking at plaster-clad or monolithic homes from that period often commission a specialist weathertightness assessment in addition to, or instead of, a general builders report. The extra detail can make the difference between a confident offer and walking away from a property that would have needed expensive repairs. It also pays to read the inspector’s stated limitations closely, since what was not tested can matter as much as what was.