Leon Chen
Mar 18, 2023
Many New Zealand property buyers have certainly heard of leaky houses, or some homeowners have experienced leaky houses. The mere mention of a leaky house evokes a strong sense of dread.
However, leaky houses aren't necessarily unbuyable. Some leaky houses may have excellent locations, offering significant appreciation potential after renovation or redevelopment. Some New Zealand property investors have their own methods and experience in investing in leaky houses, but most buyers may have limited knowledge about leaky houses in New Zealand. So, how can inexperienced buyers identify and distinguish leaky houses?
First, we need to look at when the house was built. In New Zealand, most buildings with a high risk of leaks are those built between the 1990s and mid-2000s, using a monolithic plaster-plastered exterior cladding system (typically without eaves or with a flat roof). This type of cladding usually has a continuous or smooth appearance, consisting of a monolithic exterior made of polystyrene or fiber cement board coated with plaster. This is what people call a plaster cladding. If you are interested in a house or apartment with this type of cladding, it is strongly recommended that you have a professional builder or waterproofing engineer thoroughly inspect the property, as many leaks are not immediately apparent. Repairs to these buildings are often very expensive, so it is crucial to gather as much information as possible before purchasing.
In New Zealand, a leaky house or building typically refers to a structure where moisture seeps between the exterior (exterior walls) and interior walls. Due to a lack of drainage and ventilation systems between the cladding and frame, water cannot escape and accumulates inside the walls. Over time, the walls and frame may rot, causing structural problems. Furthermore, rotting wood can breed dangerous fungi, whose spores and odors pose serious health risks.
If the property you are buying is known to have leaks or is at high risk of leaks, be sure to consider the health risks to the house and the potential financial impact (banks may refuse to lend, and the house may be harder to sell). Information about leaky buildings may not be comprehensive, so be sure to seek advice from your lawyer or a specialist in the field.
In New Zealand, leaky houses are often referred to as "weather tightness problems" or "leaky houses." As a buyer, you should be very careful if you see these terms in your contract or related documents. If you choose to buy a property that is known to have leaks or is likely to leak, make sure you know how much it will cost and how long it will take to repair the property.
The image below can serve as a key point for checking for leaks in a house. Checking these locations can generally uncover existing or potential leaks.
To help you better understand information related to leaky rooms, we have compiled some frequently asked questions below:
1. Are all houses with plaster exteriors leaky?
While not all plaster walls are inherently leaky, they do have a higher probability of leaking. The most typical leaky plaster house exhibits the following characteristics:
1. Built between 1990 and 2004; 2. Mediterranean-style townhouse or apartment; 3. Flat roof, no eaves or very narrow eaves; 4. Interior balcony, i.e., the balcony is inside the wall; 5. Exterior wall is a single-piece plaster structure; 6. There is no cavity between the exterior wall and the timber frame.
2. Can detached houses also leak? Even if the bottom is brick and the top is plaster, is that not okay?
Around 2000, a large number of detached houses in New Zealand featured full plaster walls, or brick walls with plaster on top. This type of house is now the most common and controversial in the Auckland property market, causing considerable uncertainty for many potential buyers. However, compared to terraced houses and apartments, detached plaster houses are less likely to leak because they lack other features typically associated with leaky houses (such as flat roofs and no eaves). Nevertheless, to minimize risk, potential buyers are advised to conduct humidity tests and consult experts, especially regarding full plaster houses.
In addition, buyers need to consider that the concerns you have today will also be the concerns of future buyers. It is a fact that Plaster homes are priced relatively low, so be prepared.
3. Is there a risk of leaks in brick houses built in 1998? Which years of construction are likely to have problems?
The external manifestation of a leaky house is a plasterer veneer, which is essentially an untreated timber frame. Theoretically, all houses built between 1995 and 2004 could potentially use untreated timber, and any improper maintenance of the veneer could lead to leaks. However, brick, cedar, or weatherboard veneers have natural or artificial cavities, making it less likely for water to seep into the timber frame, thus significantly reducing the risk of leaks compared to plasterer houses.
4. The inspection has been done and there is no leak. Is it okay to buy it?
Generally speaking, if a house has been built for over a decade and the indoor humidity test results still meet the standards, the likelihood of structural leaks in that house (this applies only to detached houses; the situation is more complex for townhouses and apartments) is indeed quite low. However, regular maintenance is still required after purchase, as plaster exteriors require more stringent maintenance than other exterior walls. Of course, this is not a 100% guarantee, and potential risks still exist.
5. If I replace the entire exterior wall of a Plaster house and get a CCC certificate, will there be no problem?
If a plaster house (including detached houses, townhouses, or apartments) has had its exterior walls completely replaced and has obtained a Code Compliance Certificate (CCC) from the city council, it at least indicates that the house was problem-free when it obtained the CCC. Furthermore, most exterior wall replacements now include a cavity, further reducing the risk of leaks. However, for the same reason, no one can guarantee 100% safety, and buyers should still consider all factors before making a decision.