Recent developments have shown that CLT can provide significant time and cost advantages as well as the green benefits, writes Pascal Mittermaier.
Which 10-storey apartment building took a team of five skilled labourers just 10 weeks to construct?
This was recently achieved by Lend Lease at its residential development in Melbourne, Forte, which became the world’s tallest timber building. The key to this was cross-laminated timber, or CLT, which I believe is emerging in the UK as a real sustainable alternative to conventional structural materials.
Using CLT in the UK
Indeed, the considerable benefits in terms of sustainability, ease of construction and, ultimately, cost savings has led Lend Lease to introduce CLT across much of its UK development portfolio, including the first phase of its £1.5bn regeneration of Elephant and Castle.
“We may now be on the cusp of a step change as the material becomes better understood domestically”
CLT has been used in cutting-edge developments overseas for more than 10 years. In the UK, however, the material has not yet gained recognition as a truly viable and sustainable alternative to traditional construction methods.
We may now be on the cusp of a step change as the material starts to become better understood domestically and its use becomes much more prevalent.
Environmental benefits of timber
CLT is a durable, strong and sustainable solid wood alternative to concrete. Timber has a number of qualities that can deliver significant benefits not only for the environment, but for occupiers, communities and clients alike.
Products are manufactured offsite and imported to the UK from specialist manufacturers who source from certified forests in countries such as Austria. The production and erection process generates zero waste and helps minimise on-site pollution – be that noise, air or water.
It reduces the number of deliveries by up to 7.5 times compared with reinforced concrete. CLT also has excellent thermal qualities, in some instances reducing the amount of energy needed to heat buildings by approximately 40 per cent, subsequently lowering costs for occupiers while also reducing CO2 emissions.
Time and cost savings
There are also a number of time and cost advantages in using timber as an alternative to conventional building materials, in addition to the environmental benefits.
“Construction time is typically reduced by anywhere between 25 and 50 per cent, with programme savings of 33 per cent”
Typically, construction time is reduced by anywhere between 25 and 50 per cent, generating programme savings of around 33 per cent. Quicker construction also allows for faster cash realisation from projects, allowing capital to be redeployed with maximum efficiency.
A handful of contractors and local councils have experimented with CLT in the UK in recent years, building schools, community centres and even a small number of low-rise residential blocks.
However, its usage has been sporadic and, where it has been implemented, it has been done so on a relatively small scale.
Providing a triple benefit
But the benefits of CLT will increase dramatically once it is adopted on larger-scale projects, as contractors become more familiar with the material and increase their use of it.
Elsewhere in the world, CLT has already proven itself to be a viable alternative to concrete in the construction of buildings up to 10 storeys. Further testing suggests CLT could be used for much taller buildings in the future.
“Cost savings could be transferred into other sustainable intiatives that are often overlooked due to financial constraints”
As an initiative that demonstrably reduces costs, CLT could help to focus the sector on sustainability. Cost savings could be transferred into other sustainable initiatives, such as water consumption and recycling, which are often overlooked or neglected as a result of financial constraints.
Working with CLT has the potential for a true ‘people, planet, profit’ outcome with a triple benefit: a cheaper overall construction programme; a better carbon and environmental profile; and a potentially healthier, more engaging living environment.
Given the proven benefits and potential opportunities that CLT provides, I expect it won’t be long before others follow suit.
Pascal Mittermaier is head of sustainability EMEA at Lend Lease