With a multi-residential project underway in Campbelltown believed to be Australia’s largest cross-laminated timber building by weight, design and construction company Strongbuild is finding its focus on timber is paying off.
The 16-year-old company has built its head office at Norwest Business Park in Sydney out of glulam, designed by James Fitzpatrick from Fitzpatrick + Partners, and has another 15 timber projects on the books, including aged care, retirement, multi-residential, communities, townhouses and detached homes.
In fact the company is so confident about the material’s future, it’s currently developing its own timber prefabrication plant at Norwest, which is expected to be fully commissioned by November this year with 40 people on staff.
In an interview with The Fifth Estate, Strongbuild managing director Adam Strong outlined the many reasons for his company’s commitment.
There is the whole “consciousness” around timber and its sustainability benefits that is “growing massively”, the climate change angle and the “huge benefit” of CLT compared to concrete.
One of the company’s tactics, for instance, is to take clients and consultants on tours where they visit a concrete building, followed by a timber building. And he’s found getting client buy-in for timber easier than he estimated.
At Macarthur Gardens, the Campbelltown project, the benefits go both ways, to the builder and the client, affordable housing provider BlueCHP, which has wholly funded the development.
CLT has speeded up construction, and contrary to the nervousness of many in the industry, it’s reduced risk, Strong says, pointing to the client’s limited budget and a compressed timeframe to meet the requirements of the National Rental Affordability Scheme.
The project comprises three towers of six, seven and eight levels, with a combined 110 apartments. By comparison, Forte at Docklands, also timber, delivered 23 apartments and four townhouses over 10 levels.
The 45 apartments in the eight-level tower will be sold on the private market, and the other two towers retained by BlueCHP to deliver affordable rentals.
The project will use around 3000 tonnes of CLT produced by Binderholz in Austria. Strong says the company has an exclusive partnership arrangement with the manufacturer for the use of its material in Australia.
The first panels arrived on site last month and installation has commenced, with completion expected by the end of this year.
“It is fantastic to be given the opportunity to work with a forward thinking, innovative client like BlueCHP who shared our vision of using CLT for this landmark project,” Strong says.
The project was originally designed for conventional concrete and steel construction.
But according to BlueCHP’s chief executive Charles Northcote, when Strongbuild presented the alternative construction method, the organisation was “immediately enthused”.
“The idea of being able to trim a substantial amount of time off the build while ultimately creating a softer, warmer, environmentally friendly living experience suited our company objectives perfectly.” Northcote says.
Timber locks in loads of carbon
The builder worked with AECOM, whose buildings structures leader Marc Colella identified CLT’s reduced carbon footprint for the development.
“The benefit of CLT is that it provides an effective alternative to concrete and steel but without any of the environmental impacts,” Colella says.
“Concrete has an energy intensive production process, creating a lot of greenhouse gases and contributing to the high carbon footprint of most buildings whereas each cubic metre of timber used in this project has 800kg of carbon locked into it.
“[CLT] is a modern material ideally suited to modern developments like The Gardens and one that is sustainable and that will create a better living environment for all its residents.”
Strong says the business model is an end-to-end one – from design to construction. While CLT is the preference for large projects, many smaller projects are using lightweight timber.
The company has had a preference for timber solutions for the past five years because of its thermal and acoustic performance, plus its reduced construction timeframes, he says.
Environmental performance is showing in ratings. A 2014 project, the Pilot House, in which Strong and his family are living, was assessed as 9.5 star NatHERS. Constructed largely from timber the home aims to be net zero for energy through a combination of energy-efficiency, 10kW solar power generation and a home automation system to manage energy loads.
As it is tightly sealed, the house has a PassivHaus heat recovery ventilation system providing 100 per cent fresh air ventilation. Air for the HRV passes over the multiple rainwater storage pods for pre-cooling.
The house also features automated solar gain shutters that close when the thermal load reaches a set temperature, triple-glazed windows, and low-VOC paints, joinery, glues and carpets.
What the factory will do
Strong says the company’s production facility is the result of four years of research and development. It will produce both CLT-based and lightweight timber building components.
Detached dwellings, he says, will see a house finished within three to four days of the slab being completed.
Strong also says the prefabricated, panellising approach is preferable to modular because prefab allows customisation of dwellings. It also takes away the issues around transport that create a constraint for the size of modules.
“Our [houses] look like regular homes,” he says.
“The cost is similar to conventional homes but they are built 40 per cent faster.”
Other benefits of CLT include insulation and air tightness.
“We have a passion for better performing homes,” he says. “We want to provide a low energy home at no more than 10 per cent more of the standard cost [of a comparable home].”
However air tightness levels are easy to achieve in the factory setting, but not so easy to achieve on site.
Prefab also has benefits in better safety outcomes, less waste, a cleaner site, less noise for adjoining residents and cuts down the number of on-site workers. It also cuts construction timeframes and reduces weather delays.
With the skilled labour shortage in Australia, getting labour offsite is a plus. The timber methodology also takes a significant load off site supervisors.
The company currently employs 110 people across design, project management and construction, including a substantial number of carpenters.
Some of these tradespeople and half of the company’s plasterboard team will be shifted into the factory once all the plant is commissioned and the number of people working on-site for the company’s projects will be halved.
Mr Strong said that Lendlease “paved the way” for CLT in Australia. Now there is growing number of options, with the new XLam plant planned for Albury-Wodonga that Strong says his company will consider as a supplier if the product is cost-competitive with the current Austrian supplier.
An advantage he is also looking for is the potential for larger panels. Currently, imported panel size is constrained by the dimension of the shipping containers.
Strong says the whole “consciousness” around timber and its sustainability benefits is “growing massively”, particularly for conscious developers and governments.
The climate change angle, he says is a “huge benefit we sell”, particularly when comparing CLT to concrete.
“There are more pluses and benefits from timber from a sustainability point of view.
“The timber sells itself.”