Construction will soon commence on the first multi-storey cross-laminated timber building in South Australia, with builders Morgan and Hansen getting the green light for a five-storey mixed use residential project in the inner-urban Adelaide suburb of Kent Town.
Managing director Andrew Morgan said the company had been looking for a site to develop a CLT project for some years, following extensive investigation into the possibilities of mass timbers for sustainable and speedy construction.
- See our story Timber: the next evolution in construction
The South Australian Development Assessment Commission approved the $27.3 million “Verde” project earlier this month, following the project’s successful progress through the SA Design Review Committee. The development will comprise 54 apartments in the upper three levels, seven small home offices in the lower two levels along with commercial offices and ground floor retail.
Designed by SA architect Proske, the project is a joint venture between South Australian family-owned developer FA Mamac and builders Morgan and Hansen.
CLT will be used for all the load bearing walls, floors and ceilings of the residential levels, with conventional concrete and steel construction for the lower two levels.
Mr Morgan said the lower levels being non-timber would protect against termites.
Research laid groundwork
Prior to his firm procuring a site, Mr Morgan had undertaken research including touring CLT manufacturing plants in Austria and Germany and looking at projects using CLT in London. He told The Fifth Estate this research convinced him of the benefits of using CLT even before he made visits to Lend Lease’s Forté in Docklands, Melbourne while works on the project were underway.
These benefits include speed of construction, a reduction in the number of trades on site, ease of construction, and sustainability benefits in terms of the natural origins of the material, thermal performance and a major reduction in construction waste.
“I estimate this build will be 30 per cent faster than a standard build,” Mr Morgan said.
“CLT as a building material is very, very precise, so there is very, very little wastage. All the penetrations for services and electrical are routed in at the factory, so all the critical paths through the floor plates are premade. This saves the plumbers, electricians and other trades time on site, and the penetrations can be accurate to the millimetre.”
This also takes away the need for waste-generating activities such as drilling or cutting concrete for services, also steel fixing and formwork for slabs, and concrete slab construction itself. Also, by saving time and on-site labour for the subtrades, the trade contractor’s costs are also reduced.
“When you see CLT and how it is made and where it is made and where the material comes from, it’s a very logical choice of material. It’s really a very simple choice of material. The way I explain it [to some people] is it’s like those popsicle stick mats you used to make as a kid to put under Mum’s teapot. By the time you layer all those popsicle sticks across each other and glue them, you try breaking that, and you can’t; it’s very strong. CLT is the same principle, just more accurate and on a larger scale.
“Most things that work well are simple.”
Mr Morgan said the Fire authorities in South Australia were “very conservative” and required some initial convincing of the fire safety aspects of the building. However, plans to install a sprinkler system throughout the CLT sections resolved their concerns.
Sustainability in the envelope and in design elements
“One of the big benefits of the CLT will be liveability,” Mr Morgan said. “These apartments will be a lot cheaper for [occupants] to run than conventional steel, concrete and gyprock construction. That’s where mass timber really has benefits, and it is a natural product.”
Other sustainability initiatives in Verde include light courts or internal courtyards in every apartment for natural light, and the specification of LED lighting throughout, which Mr Morgan said is now standard for his company’s residential projects.
The plans also include ceiling fans to reduce the need for airconditioning, and every apartment will have natural cross ventilation. This has been achieved by designing in a 400 square metre landscaped piazza-style courtyard that sits above level two in the centre of the building and creates a full-height void.
“We had been looking for a site which was big enough for something like the courtyard,” Mr Morgan said.
Five fairly mature trees will be planted in the space so it functions as green open space for residents and adds a “calming” green outlook from inward-facing windows, as well as cooling air in the courtyard and void. Large louvres will be installed on the prevailing wind side.
Rainwater harvesting and a 100,000 litre underground rainwater tank will be installed, and the water will be reticulated to all the apartments for toilet flushing. Mr Morgan said this is standard practice in Adelaide residential projects, both detached and multi-residential, as the city is “very water aware”.
Design review process smooths the path to approval
Mr Morgan said the project team initially felt a degree of caution about the Design Review process, but found that it contributed to improvements and led to a smoother development approval process.
“In all my 25 years of building, I’ve not come across a development approval process as efficient and productive,” Mr Morgan said, adding that previous experiences with standard council approval processes had often proved “obstructive”.
He hopes the process will continue to be implemented, and said that if it were to be taken away, it would “lead to a set-back”.
“The State Government has really got their [act] together on this, and is really making some sensible planning decisions. [SA Government Architect] Ben Hewett was at pains to make it clear this was about making it the best project we could get to.
“The process did not have the feeling you get at the local government level where you don’t get constructive advice and criticism.
“You’ve got to have a strong central character [like Ben Hewett] in the room, because you put the proponents in the room plus four other architects, and [Mr Hewett] helps it to stay on track.”
Mr Morgan said Verde was “the most innovative project” his company had ever undertaken, in a market where innovation is not always greeted with enthusiasm.
“Adelaide is very conservative; it doesn’t have the peaks and troughs [in the market] of Melbourne and Sydney. So for our client, size of the apartments is critical, and these are a little bit bigger than average. Adelaide also has a problem with being too high off the ground; there really isn’t much residential building in the mid tier of four to six levels.”
The first construction work on Verde is expected to commence at the end of this year.