Type to search

Alex de Rijke of dRMM on timber high-rises

Alex de Rijke of dRMM on timber high-rises


All images courtesy dRMM Architects.

This article originally appeared in AR144.

Why do architects want to build high? Especially in timber? Like testosterone-fuelled explorers driven to go further, the challenge is simultaneously unnecessary and irresistible. The biggest erection wins the global reputation, the research stakes, the media interest, the TED talk and, most of all, the short-lived title, the world’s tallest timber tower.

How high is high in timber? Although way higher, unbuilt proposals compete for the title of world’s tallest timber building, the tallest built timber tower is currently 10 storeys – Forté by Lendlease in Melbourne, built in 2012.

dRMM Architects have pioneered engineered timber architecture in the EU, exhibiting the first CLT flatpack prototype house in Oslo in 2006 and UK school buildings from 2007. In 2009, dRMM proposed an engineered timber 6000-seat Handball Arena for the 2012 London Olympics and 10-storey CLT apartment building designs to developer LendLease for the Athlete’s Village. Too ahead of its time, these were built in concrete, as was the rest of the London Olympics development. In 2008, in collaboration with Norwegian practice, Helen & Hard, dRMM proposed 14-storey timber towers in Stavanger, Norway. These were designed as all-timber structures, but eventually built in 2014 as concrete and timber hybrids.


In 2015, the news was full of competing designs and projects due to go ahead for much taller timber towers. The main contenders in the race for height include Architekten Hermann Kaufmann of Austria, who has designed a 30-storey timber/concrete hybrid structural system with Arup, entitled LifeCycle Tower One, and MGA of Canada, with a tower of 35 storeys proposed with DVVD, as part of the Réinventer Paris competition.

The design intentions are laudably grounded in global environmentalism, but the outcome is the signature architecture of towers. Ironically, the typologies proposed speak the language of steel-frame orthodoxy, much like Mies van de Rohe’s timber high-rise buildings of the 1960s.

In an age that appears to have forgotten that everything used to be built in timber, the strategy of employing familiar forms, but with a substitution of construction material, is a reassuring way to put clients at ease. The perception of the ‘risk’ of using ‘new’ construction materials is assuaged by the orthodoxy of the architecture of the right angle.

But the sky’s the limit for the fast-evolving world of modern timber construction techniques and the architectonic expression of ‘new’ material and form remain underexplored. The relevant question is not how high can you go, but do you really need towers to achieve urban density? And, if so, at which height does it stop making sense to use 100 percent timber? The absurdity of structural perversity is the actual limit for timber construction.

It is worth noting that the tallest trees (Californian redwoods) are beautifully resolved structures, which rarely grow higher than 100 metres, around 33 storeys.

For 20 years I have been, through dRMM and academia, advocating laminated timber’s outstanding versatility, weight to strength performance, sustainability, speed and endless attraction. Together with Arup and the American Hardwood Export Council, dRMM invented cross-laminated hardwood. The Endless Stair (2013) was specifically created to demonstrate engineered timber’s massive potential for the construction industry. But, as a timber architecture purist, I hesitate to advocate very tall, all-timber structures for the sake of simply being possible or higher, or to pretend that what are actually hybrid structures are ‘timber’. Concrete, steel, glue and glass are essential components of the design and what is important are the ratios. To build 30-plus storeys high in 100 percent timber, whether as a frame or mass wood construction, currently means using more material than is efficient; the top-down progressive loads mean that the lower levels of the tower would literally be a forest of wood.


The considered answer is not the tallest timber tower, but clever composite structures, as well as new high-density building typologies. Mixing in, but reducing steel, concrete and carbon to a minimum, while exploiting timber’s unique ability to invert the construction industry paradigm for carbon production, pollution and waste, is the future.

Cities are not made up of housing alone, however, with the appetite for land that high-rise development demands creating other issues. A result of the housing crisis in London is a growing exodus of manufacturing and service-based industries. The demand for housing, combined with exorbitant investment profitability, coupled with change of use planning policies means that competition among residential developers to acquire urban land is acute. Consequently, large or medium-sized inner-city sites are far too costly to justify the classic industrial single-storey shed typology. The traditional compound of ground-level light industrial workshop units arranged around level access is no longer economically viable.


dRMM’s modest response is the Stacked Workshop engineered timber prototype. This development operates on the premise of exploiting inner-city sites for workspaces that are too small, too difficult and not desirable enough a location to offer serious residential development, with the last, as a result, affordable.

Stackaed Workshops_dRMM Architects_model by dRMM Architects

A small footprint, lift-access light industrial workspace typology has been designed, offering a medium-rise modular CLT timber structure as high-density ‘start-up’ workshops. The first 14-unit example goes on-site in Greenwich in 2016.

The land usually needed for the generic single-storey compound of light industrial steel sheds, arranged around vehicle access, would have been circa 3000 square metres, depending on layout and parking provision. Steel manufacturing produces more carbon than steel. The average CO2 intensity for the steel industry is 1.9 tons of CO2 per ton of steel produced*. A metric ton of structural timber represents minus 1.6 tons of carbon, thanks to sequestration. The automatic light industrial steel-framed building, clad in steel or aluminium siding, is inherently high-energy, environmentally and architecturally dumb. The engineered timber and glass Stacked Workshop design provides the same amount of, but arguably better, workshop accommodation, but uses only 600 square metres of land and is carbon hoarding. It’s deliberately not sky-high, but rather high-density and low-energy – a modest new typology to make cities work for people and the planet.


You Might also Like

Leave a Comment

Your email address will not be published. Required fields are marked *