An expert's guide to reducing your flood risk

Australia is becoming increasingly known for its wild weather, with bushfire and flooding events topping the list. These have a direct impact on how we build and renovate homes for the long run.

When retrofitting an existing home to withstand extreme conditions, flood prevention is something many Australians are now placing at the heart of their design plans.

"We're seeing floods happen more and more frequently," says Brent Fitzpatrick, Director at Fabric Architecture. "I think if you're re-building, strategic thinking around your construction technique would be the way to go."

Find out your MHFL

"If you're in a flood zone, your first port of call is to determine your Minimum Habitable Floor Level (MHFL)," explains Fitzpatrick.

"Coming from council, your MHFL outlines the minimum level you can build above ground level and is the crucial starting point for architects and builders, as it will inform the design or how we connect an addition to an older part of a home."

Clever structural design will change the game

"One of the biggest concerns and issues from a design point of view is raising the height profile of a home – how you make it look like it was meant to be and how you integrate that into the design of the building," Fitzpatrick adds.

But as we know, extreme flooding can still engulf raised properties. So structural integrity is paramount, utilising heavy-hitting materials in a design that allows the building to be washed down and dry out.

Traditional building techniques use timber framing and plasterboard, which are prone to swelling and rotting. Now, steel construction and breathable design are paving the road to resilience.

As the water-resistant fibre cement sheets are removable, homeowners can unscrew them after a flood or severe storm to inspect damage, remove debris and dry out the wall cavity, then reassemble and continue to live in the home.

To allow a property to dry out successfully, Fitzpatrick incorporates a cavity into his designs.

"We detail all our homes with a ventilated cavity between the stud and cladding layer, which makes a massive difference to the longevity, useability and thermal comfort of the home."

Suncorp's One House Project is a great example of strategic construction techniques, using a steel stud framing system on a 100mm concrete upstand. Internal wall linings are a fibre-cement sheet system with vertical battens covering the joints.

"The One House project was designed for renovators and homeowners, to consider 'resilience', not just aesthetics, when designing, renovating or maintaining your home," says Suncorp's Bernadette Norrie. "One House has shown you can create a contemporary, aesthetic and affordable home built to withstand extreme weather like storm, flood and fire so that you and your family can live in awe of mother nature, not in fear of it."

Choose construction materials wisely

Water damage can wreak havoc on any home, with mould's insidious grasp causing ongoing destruction and health issues for home dwellers. Material choice should therefore prioritise water resistance.

"After the amount of water and floods the east coast of Australia has copped recently, mould is everywhere from Melbourne right up to Queensland," says Fitzpatrick. "It's inside, it's outside – it's at the forefront of our minds right now."

"If you're in a flood zone you want to build to a safe height and have a solid construction. But you also want to eliminate any product that could rot or grow mould," he adds.

Homeowners should take advantage of concrete, even considering it for flooring. Double brick walls, masonry and steel are also good options, according to Fitzpatrick.

"Materials that are resilient and can be washed down are ideal. Inside, replace any plasterboard product below or near that minimum height line with fibre cement sheet, as it won't rot or get mould infestation," Fitzpatrick continues.

The other big hitter is your insulation.

"We need insulation in homes to keep us warm or cool, but natural wall insulation doesn't like being immersed in any kind of water.

"Use a product called closed cell insulation instead, which is kind of like a polystyrene board. It's much more water resistant and can dry out to prevent mould issues," he advises.

For windows and doors, uPVC windows work well because they're water resistant and won't rot, but their incredible seal also works to keep water out that little bit longer.

Save on repairs with savvy interior choices

An unfortunate reality of extreme flooding is that water will likely enter your home at some point. Therefore, interior choices will also be guided by resilient materials that mitigate water damage.

"You would eliminate MDF, which is commonly used in kitchens, as it will swell in water," says Fitzpatrick. "Even solid timber you'd want to avoid, because if it's in water for an extended period of time, it will also swell, absorb moisture and then mould will start to grow inside."

Fitzpatrick recommends solid materials – a concrete base or hob your cabinetry can sit on, steel legs or a concrete kitchen island, for example.

Raise your electrical and use multiple circuits

Typically, electrical wiring is run low in homes. However, when designing to reduce flood impact, this is one tradition worth tweaking, along with raising the height of power points.

"You could run electrical wiring in the roof and bring it down your walls," explains Fitzpatrick. "If the flood level goes, say, half-way through your house, then you'd want your electrical above that level."

"Another way to increase your chances of having access to power after a flood is to run the home on two or more circuits," he advises.

As extreme weather events become more frequent, it's important that the homes on every street, neighbourhood and community are prepared for storms and bushfires. That's why Suncorp have created initiatives to put Australia on the road to resilience. To find out more, visit resilience.suncorp.com.au