A great many New Zealanders are all too familiar with the experience of living in a cold, damp house. “Weeping” windows, clothes, bedding and upholstery that are moist to the touch, and air that simply never feels dry: these conditions have long been tolerated.

But that’s changing now. There’s growing awareness of the havoc damp living environments can wreak on people’s health. One University of Otago study suggests that up to 1,600 New Zealanders die each year due to health conditions arising from cold, damp houses.

This has played a big part in the drive towards warmer, drier homes and the introduction of the Government’s new Healthy Homes minimum standards for rental properties. Along with insulation and heating, ventilation is a key part of the standards. So in this article, part two of our three-part series, we take a look at what landlords need to know about ventilation.

Not Just Something Nice

Not only can damp conditions in a house have serious health effects for the occupants, but they can cause major damage to the house itself. That’s because damp leads to mould which can cause timber to decay and impact on a property’s structural integrity. It can also damage joinery, paintwork, wallpaper and wall linings. All of this makes for ongoing maintenance issues and high costs.

But effective ventilation removes excess moisture from a house, as well as ensuring its air quality is not damp. This makes the property drier and easier to heat, which keeps tenants healthier and better protects the house itself. In turn, this means a property is easier to market and attracts higher rents and longer-term tenancies.

While savvy landlords have long been aware of the benefits of good ventilation, the new standards ensure it is no longer simply something nice to do. As at July 1, 2019, the standards become law and ventilation to the required level will become compulsory.

The ventilation standard has a two-fold focus in its requirements. One aspect is that each habitable space in a premises must have at least one window or door that opens. The other aspect, which has received more publicity, is that all kitchens and bathrooms must have extractor fans of a particular size and capacity installed. There are some exemptions to the requirements, notably if it is not reasonably practicable to install extraction devices. However, the criteria for “not reasonably practicable” is quite stringent. If a property does have an exemption to the ventilation standard, landlords must describe why, in the information statement they now have to provide.

According to Tenancy Services, landlords are responsible for maintaining any ventilation systems. But tenants are responsible for ventilating the home during their tenancy. This includes running any ventilation systems, using extractor fans and opening windows and doors regularly.

Beyond The Basics

The new standard means that landlords need to start thinking about what they can do to make sure their house is well ventilated, while still keeping it secure.

To achieve this to a level that meets the standard, Tenancy Services suggests installing extractor fans that vent to the outside in the kitchen and bathroom and a dryer that vents to the outside, as well as window stays, which allow tenants to safely open windows to let fresh air in.

It also recommends that landlords consider installing a central ventilation system that sources air from the outside. Central ventilation systems work to constantly replace the air in a home so that there is a regular supply of fresh air throughout the house.

They can use positive pressure to filter fresh air from either the roof cavity or from outside or they can employ balanced pressure to extract stale air, use a heat exchanger to reclaim the energy and send the stale air outside.

Such systems are not currently a requirement under the standard. But they significantly up the level of moisture removed from a home and provide a more robust degree of protection.

Unovent is a company which specialises in New Zealand-designed home ventilation systems. Their spokesperson, Tracey Neilson, says many people are unaware of just how much moisture a household creates in the course of its daily activities.

“Cooking, showering, washing and drying the laundry, even just breathing … It all generates a vast amount of moisture. And you need to find a way to get it out of your house because it’s bad for both the house and, even more, the occupants of the house.”

Landlords should think about getting a whole-home system installed, she says. “Because they don’t know what conditions their tenants will live in. They might not open the windows much or they might have lots of smelly, teenage boys. A ventilation system makes for a drier, easier-to-heat house, which adds value to their asset.”

There is a wide range of ventilation products on the market – from extraction fans to whole-home systems. Different products are better suited to different types of houses and situations and costs vary quite widely, so it’s worth seeking professional advice on what to buy, Neilson recommends.

“Expert DIYers can install extraction devices, but most people should get them professionally installed to ensure it is done correctly. They might save a few dollars going DIY, but it’s easy to get it wrong and then the product won’t work efficiently. Ventilation systems are more complex and should be installed by a professional.” She adds that because whole-home systems have separate fans located in each room it is possible to introduce them room-by-room, which provides some flexibility on costs.

Additional Options

Alongside extraction devices and ventilation systems, there are other options that landlords can utilise to help battle excess moisture in their properties. One of these is a Showerdome shower top for the bathroom, which reduces moisture by preventing the creation of steam from the shower.

Showerdome’s Claire Van Horn says it is an effective solution for landlords as, unlike extractor fans that require tenants to remember to turn them on and off, a Showerdome is just there, working away, with no input. Another benefit for tenants is that there are no on-going running costs.

“As there is no moisture laden air in the bathroom, paintwork, fixtures and fittings all remain completely dry,” she says. “That means they don’t need replacing or repairing as often. Bathroom maintenance is significantly reduced and that can equate to substantial savings.”

With a Showerdome, there is a one-off cost involved in the purchase and fitting of the product. If the product is put in by an authorised installer it costs $434 (GST included). Taking the DIY option comes to about $299 (GST included) for the product.

Landlords have until 2021 to comply with the new standards. So NZ Property Investors’ Federation executive officer Andrew King doesn’t think landlords need to rush out and install a whole range of products right away.

Some details of the new standards remain unclear, he says. “For example, there could be problems with putting an extractor fan into a kitchen if there isn’t an exterior wall. That means they should wait until the standards and what exactly they require have been clarified further.”

However, rental property owners should do a stocktake on their property to ensure they know what they have to do to comply with the ventilation standard. “That will give them some idea of the sort of costs they might be looking at and how they might want to start adjusting their rents.”

He adds that the NZPIF is looking at doing some bulk deals on ventilation products for its members which will mean some cost savings for landlords going forward.