Construction materials are typically judged not just on their strengths but also on how well-known those strengths and physical qualities are, so it is perhaps no surprise that timber frame suppliers combine traditional, sustainable materials with state-of-the-art architectural principles.
The shining beacon of this approach is the emergence of the skylines of many cities across the world of plyscrapers, a set of very tall buildings that are made either entirely or predominantly from mass timber building materials.
They are a profound design challenge because they rely on getting the absolute most from wooden materials, using systems such as cross-laminated timber (CLT) and glue-laminated timber (glulam) to build grand wooden buildings that reach the heights previously thought possible only through steel and concrete.
However, one of the most fascinating concepts in this regard is the emergence of a huge project in Chicago that, if constructed, will revolutionise how sustainable buildings are developed.
A Storeyed Experiment
Part grand centrepiece of the skyline of the Windy City, part realisation of a years-long architectural experiment, River Beech Tower is a proposed plyscraper initially proposed in 2016 that was intended to answer every difficult question yet asked about high-rise wooden construction.
The building, designed to be 228 metres tall (748 ft), would if completed be by a significant margin the tallest wooden building in the world, with its only rivals being similar proposals like the Oakwood Tower in London and the W350 Project in Tokyo.
This scale alone makes it a fascinating discussion point when it comes to wooden buildings, as any technologies that make it possible at that scale will inevitably trickle down to wooden homes of any other shape and size.
However, it is not just the fact that River Beech Tower would be a record-breaking height, but the methods it uses to achieve that height.
The design, which architectural firm Perkins & Will claims is achievable with commercially available timber materials, but a construction method far different than any used thus far.
Whilst most tall timber buildings either use a concrete core or steel reinforcements, River Beech aims to use a system known as “exterior diagrid”, which uses a lattice honeycomb of diamond-shaped modular structures to create an unparalleled level of strength for timber.
It works by using one of the biggest natural strengths it has, which is its ability to take axial loads, easing the vertical and lateral loads on the material by evening the load distribution throughout the wooden elements through the diagonal grid.
Rather fittingly, rather than wood being used as a veneer for metal structural components, the lattice would feature aluminium cladding to cover the exposed beams and further improve its weatherproofing qualities.
The claim, therefore, is that a building in a city nicknamed the Windy City could be made from wood using this method without the use of additional traditional reinforcement materials, allowing for a significantly more sustainable result.
The conceptual building would have featured 80 mixed-use floors, incorporating offices, duplexes, communal spaces and an interplay between public and private spaces in one building.
It would also prove that mass timber can meet and exceed all building regulations standards, a major but often unheralded stumbling block that often leads to larger timber buildings using concrete and steel cores in the first place.
Whilst timber is extremely structurally sound, safe and resistant to common concerns such as fire, earthquakes and gale-force winds, building regulations often do not reflect this.
Wooden skyscrapers are an alluring concept, and not just because sustainability in construction is no longer a nice-to-have but a necessity. Construction has historically relied on concrete at a rate that has made it one of the largest single-carbon emitters in the world.
Beyond the idealism and the fact that timber frame buildings are just beautiful works of art as seen with the likes of Ascent MKE, there are considerable practical and economic benefits.
It takes far fewer people and less dedicated machinery on a construction site to build a timber structure than it would one made from concrete, steel and masonry,
You do not need a cement mixer, you do not need to wait for mortars to dry and you do not need to carefully sculpt and prepare each component on site.
The entire ecosystem of prefabrication is designed around cutting wood into shape, which means that an entire skyscraper can be fabricated in a manufacturing centre, transported to the site and put together in a matter of weeks and months rather than years.
Given that a major cost involved in construction is the skilled workers on-site, this can translate into significant savings for a better end product.