Taking Timber to New Heights

Forté Apartments

In just a few weeks, Australia will become home to the tallest timber building on the planet. Forte, a residential apartment complex rising over 10 stories, will also be the first of its kind on the continent. Lend Lease, the company behind the innovative, environmentally friendly project, is constructing the 23 boutique apartments and four townhouses using Cross Laminated Timber (CLT) to create a revolutionary tower with walls, floors, and ceilings made of solid wood.

Cross Laminated Timber, or CLT, is an engineered wood product that proponents believe has the potential to rival steel and concrete as the go-to building material of the future. The product is formed by bonding thin timber boards to one another, creating layers. Unlike other engineered wood products such as glued laminated timber – or GLULAM – each board is positioned perpendicular to the previous one, enabling the material to retain its shape better. Up to 11 layers are then coated in glue, hydraulically pressed, and trimmed until a solid timber panel is formed.

The process is completed using computer guided saws and drills to carefully cut out the exact measurements of each architectural detail, from windows and doors to ventilation and plumbing openings, as well as passageways for electrical wiring. Although the end result may sound like oversized plywood, the manufacturing process actually creates a product able to withstand the same pressure as prefabricated concrete. Furthermore, because CLT is designed and produced in a controlled environment, it takes less time and money to build and can achieve higher quality finishes.

But can a high rise really be constructed entirely from wood – even wood endowed with super strength? Proponents explain that CLT panels are more closely related to concrete than timber frame, and that CLT actually makes a lot more sense than traditional construction in which relatively small wooden beams are fashioned together using weaker materials like plywood and plasterboard. CLT panels also work together to evenly distribute the building load, insuring against progressive collapse and even enabling the building to remain standing if one area is destroyed by an explosion or other unexpected disaster.

In fact, CLT has already proven its worth in several buildings up to nine stories tall, and developers are eager to push the envelope even further. In October of this year, Forte will edge out European competition – London’s Bridport House and Stadthaus – by 242 centimetres to earn the title of world’s tallest wooden residential building. The Melbourne based project is the brainchild of Lend Lease, an international property and infrastructure group with a long standing commitment to sustainable building.

In keeping with its core philosophy, the group carefully designed the $11 million tower to minimise environmental impact throughout its lifetime. Rainwater will be collected in dedicated tanks for use in the building’s fire system and toilets. All of Forte’s common areas will use motion activated LEDs for energy efficient lighting. Tenants can also easily manage without owning a car, reducing the collective carbon footprint even further – trams and buses are only minutes away by foot and Southern Cross station is an easy ten minute walk. A bike share point is also just minutes away and tenants are provided with a dedicated bike rack on ground level. When a car is necessary, a car share point is conveniently located directly in front of the building. A vegetable garden will also be included on each apartment balcony to promote locally grown produce and healthy living.

Forte’s use of Cross Laminated Timber is arguably its greenest feature, however. In fact, CLT advocates believe that more widespread use of the material could be a plausible strategy in combating global climate change. CLT buildings require less energy to heat and cool than conventional concrete structures. Furthermore, concrete requires an energy intensive construction process that produces a substantial amount of greenhouse gases. Switching from concrete to wood significantly reduces a structure’s carbon footprint because fewer greenhouse gases are produced during the build itself. Any concrete that Forte does use contains high fly ash content, which is lighter and more energy efficient than typical concrete, yet every bit as strong.

Green Magazine reports that, when compared to the concrete and steel standard, Forte’s construction process will reduce carbon dioxide equivalent emissions by a dramatic 1,400 tonnes. Furthermore, the carbon locked inside Forte’s wood panels via photosynthesis helps to offset whatever greenhouse gases will be released during the build. The environmental benefits of CLT, combined with the building’s energy efficient design, will grant the high rise at least ten years of carbon neutrality.

Another benefit of Cross Laminated Timber is that, because the panels are premade in a factory, on site construction time is greatly reduced. By using CLT, Forte will be completed in only nine months, 30 per cent faster than with a traditional steel and concrete structure. The shorter build time translates into environmental savings by reducing construction related traffic and waste. And, because time is money for any builder, economic savings may be substantial as well.

An obvious counterargument to CLT’s environmental advantages is the fact that panels require a large amount of wood. In fact, a standard CLT wall is likely to use six times more wood than a traditionally built wall of the same size. Advocates point out that trees are a renewable resource and that CLT should only utilise timber from responsibly managed forests. Europe is the site of most of the timber felled for CLT, and the New York Times reports that Austria, which enjoys a long history of well managed forests, provides around 80 per cent of CLT panels for the world market. Rather than opting for a plantation timber, most CLT is made from European spruce, which has an average rotation of around 70 years.

Another common concern is the risk of fire. To many, a high rise constructed from wood – regardless of the high tech manufacturing process – sounds like a death trap waiting to happen. However, according to the New York Times, CLT panels can’t ignite as easily as the smaller wooden beams traditionally used in construction. As anyone who has struggled to light a campfire knows, fires are started using twigs and small bits of wood – not something as large as CLT’s massive prefabricated panels. And, if the worst should happen, the interior of a CLT panel is designed to remain intact even if the outside is charred, enabling the building to remain structurally sound. As an extra precaution, panels are coated in fire retardant finishes.

CLT technology was developed in central Europe in the 1990s, and though it has become relatively popular on that continent, the material has been slower to catch on in other regions of the world. North America has recently begun to delve into the new technology, and now, with Forte, Australia is testing the waters. The innovative structure may only be the beginning of what engineered wood can achieve, however. Many proponents insist that CLT buildings have the potential to rise much higher and believe that a timber tower will reach 15 stories in the very near future. Other advocates envision 30 storey hybrid structures utilising CLT panels around a concrete core. Although Forte holds the spotlight for today, it is anyone’s guess to what height timber might soar tomorrow.

Home Automation

Call it ‘domotics,’ and you are likely to receive a blank stare, but refer to it as ‘smart home’ or ‘home automation,’ and you will get a nod of acknowledgement. For the past few years, consumers have heard the word ‘smart’ attached to countless products and services, from food and drink to snacks like popcorn and mobile phones, which no one seems to refer to as a ‘cellphone’ anymore. Yet what, exactly, constitutes ‘smart’?

January 17, 2019, 5:45 AM AEDT