prefab houses
Ask the Inspector, Brisbane Building and Pest Inspections

Pre-purchase Inspections for Prefab Houses

If you’re in the market for a home, you’d be hard pressed not to notice the shiny new kid on the block: Prefab houses. Though they’ve been around for centuries, prefab houses are enjoying a massive resurgence in popularity. Promising to deliver greater housing affordability and sustainability in record time, prefab houses are fast becoming a serious contender vying for your attention in a cutthroat housing market. But are prefab houses a safe bet or a big gamble? Here’s why pre-purchase inspections are essential for prefab houses.

Prefab houses

Prefab houses are houses that are ‘prefabricated’: They’re constructed off-site in a factory before being transported to the site, craned into place and connected to services. Prefab houses are also known as ‘modular housing’ because off-site construction means they have to be constructed in ‘modules’ or sections small enough to fit onto the back of a truck to be transported to their destination.

Why prefab houses got a bad rap in the past

Prefab houses used to be widely regarded as the poor man’s alternative to housing built with traditional construction techniques. Their popularity reached a crescendo in the post-World War II era when the unprecedented population boom led to an insatiable demand for cheap, quick—and sometimes nasty—public housing. It’s not surprising that prefab houses developed an inferiority complex.

That’s no longer the case. Prefab houses have shaken off the stigma associated with public housing estates and have moved into the 21st century. If you’re not familiar with modern prefab houses, it can be difficult to distinguish between them and houses that have been built from the ground up on site. That’s especially the case where they’re pitched at the higher end of the market and have superior fittings and finishes.

Prefab houses: Why everything old is new again

Prefab houses are suddenly the flavour of the month. They’re riding a wave of popularity because technological advances have made them more affordable than ever before.

Modern prefab houses are usually constructed off-site in an assembly-line process. The manufacture of modern prefab houses utilises computer-aided design (CAD), computer-aided manufacturing, laser cutting and laser printing. Computer-aided design is one of the key areas in which prefab houses offer an advantage over other types of homes you might be considering.

Where prefab houses come into their own

You might opt for a prefab house if you live in a rural or relatively isolated area where there’s a skills shortage in the local labour force. That’s why you’ll find that prefab houses are immensely popular with sea-changers and tree-changers. That’s not the only reason they’re so popular, though. There are a number of factors contributing to the groundswell in favour of prefab houses:

Prefab houses and cost-effectiveness

Prefab houses are also a viable option if you need your home in a hurry and don’t have time to sit around to wait around for it to be built on site. You’ll save months by opting for a prefab house. That can save you a packet if you can avoid paying rent or a mortgage elsewhere.

Construction time’s reduced because it occurs in a controlled environment inside in a factory and not at the mercy of the elements, tradespeople who may have bitten off more they can chew or unreliable suppliers.

Prefab houses are built with military precision in an assembly-line process utilising large-scale equipment. Sure, that kind of equipment comes with a huge initial investment of money, but there are great cost savings to be made in the long run. Breaking down the manufacturing process into an assembly line in a factory allows for greater precision and consistency. The pay-off is that it also makes it easier to employ low-skilled process workers as opposed to more-expensive skilled, qualified tradespeople working on-site. If you’re a manufacturer you can reap the benefits from buying materials in bulk too. There’s also a reduction in the waste normally associated with building construction and a corresponding reduction in the costs associated with disposing of that waste.

So long as the savings are passed on to you, the owner, prefab houses are a great option if you’re looking to save money buying a house. Even when you factor in the cost of purchasing a suitable site and transportation costs, they’re generally cheaper than their standard bricks-and-mortar counterparts.

Prefab houses and sustainability

Prefab houses are also the doyenne of the global movement towards sustainability and environmentally friendly housing. They’re widely regarded as a ‘greener’ option than traditional methods of construction for a number of reason:

  • They’re more likely to be built from recycled materials so you can build with a clear conscience.
  • The process of constructing prefab houses is widely regarded as less wasteful than other types of construction.
  • Modern design means more of a focus on energy-efficiency and a smaller carbon footprint.
  • Moving a prefab house into place over a period of a few days has much less of an environmental impact on a site than full-blown excavation and construction over a period of several months.

It’s not hard for you to see why prefab houses have fast become a force to be reckoned with, particularly if you’re a fan of the movement towards more environmentally friendly housing options.

As prefabrication continues to gain popularity as a mode of construction, more established prefab houses will make it into the real estate market. If you’re looking at buying an established prefab home you need to proceed with caution for a number of reasons.

Prefab houses and where you can go wrong

For all their advantages, you need to be wary that prefab houses also come with some risks that you won’t necessarily see in a home built utilising traditional modes of construction.

Problems in the manufacturing process of prefab houses

The Australian prefab house manufacturing sector is generally smaller, less experienced and less competitive than its overseas counterparts. The volume of prefab houses manufactured is smaller, as is the demand. If you’re buying a prefab home, you need to ensure that it was manufactured by a reputable company with a good track record of compliance with Australian standards.

That said, even the best companies can come unstuck if there’s a glitch in the manufacturing process. When you’re talking about prefab houses, you’re talking about a product that is entirely dependent on precise measurements. There’s no margin for error. Small errors in the manufacturing process can translate into huge problems once your prefab house is moved to the site.

Prefab houses and transportation problems

Transporting prefab houses hundreds of kilometres and moving them into place on site is a risky process. Damage can occur and that damage might not be detected until it’s too late.

Prefab houses and site problems

Prefab houses are every bit as susceptible to site variables as homes built utilising traditional methods of construction. Good site selection and thorough preparation is key to avoiding costly problems with your prefab house. For example, if your prefab home is built on reactive soil or clay, the cyclical expansion and contraction of the soil can damage your prefab home in much the same way as it can damage a normal home. It could even be sheared apart at the joins. That’s because your prefab home has to be anchored to the site, exposing it to movement of the earth below.

Prefab houses are often utilised on extremely steep sites. Site selection is crucial with these houses due to the risks associated with landslips and the drainage of water across and below the site.

Site problems that are not rectified prior to your prefab home being moved into place can cost you dearly further down the track. This is especially the case where there’s inadequate drainage, leading to a pooling of water beneath your prefab house.

Also, keeping in mind that the construction process for prefab houses is entirely dependent on modules being moved into place and joined together. And therein lies the problem! If your prefab house hasn’t been assembled properly or insufficient attention was given to ensuring that the joins are waterproof, it could leak. A leak in a prefab home can go undetected for months or even years, silently wreaking havoc. Water ingress can be an extraordinarily expensive problem in prefab houses due to the susceptibility of the lightweight materials used in construction to water damage.

Because some people are still in the habit of viewing prefab houses as inferior to traditional alternatives, you might find that your prefab home is much harder to sell down the track. Obtaining finance to construct or purchase a prefab home can also be extraordinarily difficult. Buy one and you could find that it actually depreciates in value over time.

Prefab houses—How to protect yourself against a bad buy

There’s one very important safeguard to consider if you’re looking at your options when it comes to prefab houses. Getting a thorough and professional pre-purchase inspection from a building inspector specialising in prefab houses is crucial. It’s the only way to identify any problems with your prefab home. That way you can make an informed decision as to whether to proceed with the purchase before you find yourself stuck with a home that’s little more than an overpriced and underqualified shipping container.

In the market for a prefab home? Contact Action Property Inspections on 1800 642 465.


About Andrew Mackintosh

Andrew Mackintosh has been answering home inspection questions in the greater Brisbane area since 1995. He has personally carried out over 20,000 building inspections and is a licensed builder and licensed building inspector, Member of Queensland Master Builders Association & Institute of Building Consultants. Being the business owner and the inspector, Andrew is passionate about providing clients with excellent customer service, value for money, honest, unbiased, thorough inspection and reporting in a professional and timely manner to allow clients to make informed decisions when purchasing property.