Design-led workspace specialist TOG has come together with Waugh Thistleton Architects to explore a new approach to workplace design, paving the way for sustainable architecture.

cross-laminated timber (CLT)

In The Black & White Building TOG and Waugh Thistleton Architects have explored an ‘architecture of sufficiency’ - where every element serves a purpose, nothing is superfluous, and all materials and processes are as efficient and sustainable as possible.

The new seven-floor mass-timber office building sets out to demonstrate that timber is not just a viable alternative to the conventional concrete and steel used to build offices; when it comes to performance and sustainability, it is the preferable option. The tallest mass-timber office building in central London, the tower creates 37% less embodied carbon than comparable structures and is powered by 100% renewable energy sources.

Standing 17.8 meters tall, the tower of timber is created using renewable materials and highly innovative construction methods. The building is both a landmark in sustainable architecture and a powerful statement of intent for TOG. It is situated on Rivington Street in Shoreditch - one of London’s very first ultra-low emission thoroughfares.

TOG and Waugh Thistleton set out to create a building that minimized carbon in both its construction and, once complete, its operations. The architects proposed a structure built from the ground up using cross-laminated timber (CLT) and laminated veneer lumber (LVL). These highperformance engineered wooden materials generate much less greenhouse gas emissions in the production than steel or cement, while also being highly durable.

Built entirely from timber, it clearly demonstrates that mass timber is a viable replacement for concrete and steel in the mainstream office market, saving thousands of tons of CO2 as well as generating much less waste. CLT and LVL also have the advantage of being totally replenishable. The CLT frame was chosen for its perfect balance of sustainability, lightness, and strength. Glulam (made from gluelaminated layers of timber) is used for the curtain walling, and the columns and beams are made out of beech LVL.

The structure comprises a combination of timbers from 227 beech and 1,547 pine and spruce trees harvested from certified forests in Austria and Germany. CLT is significantly lighter and easier to transport than concrete and steel, which means that fewer deliveries are required to bring the necessary quantities to the construction site. This not only represents a carbon-reduction in terms of logistics, it also makes building in dense urban areas a more efficient process that is less disruptive for neighbours and other road users.

Because the timber components are prefabricated, and precision-engineered to be slotted together, the ‘screwed not glued’ building not only requires a smaller workforce to construct; but also has a part to play in the circular economy. At the end of its life, the building can be easily disassembled rather than demolished, and the materials can be recovered and reused. Overall, the building creates 37% less embodied carbon than a comparable concrete structure, and serves as a long-term carbon store for 1,014.7 tons of CO2 equivalent (55% of the building’s total) sequestered in the timber structure.

cross-laminated timber (CLT)

The building is powered by 100% renewable energy sources - including 80 solar panels on the rooftop. No element of the building is purely decorative; everything has a purpose. Notably, the exterior is clad in timber louvres that run from street level to the roof. These provide natural shade, reducing solar gain on the façade and boosting the natural light reaching the interior. The louvres change in depth as they ascend the building in order to optimize energy- efficiency. The use of louvres also minimizes the amount of solar coating needed to protect the clear glass windows.

The louvres are crafted from thermally modified tulipwood, recommended by the American Hardwood Export Council (AHEC). This timber is highly affordable, lightweight, readily replenished, and has minimal environmental impact. Through extensive research, AHEC has concluded that tulipwood has great strength properties relative to its weight and works well externally after undergoing thermal modification.

“Often high carbon impact materials such as aluminium and glass go on the outside of buildings. However, in this project the louvres are made from wood,” said David Venables, European Director, AHEC. “With thermal modification, you are not using any chemicals. You are taking wood and baking it. Once the timber is dry you put it into an intense heat process. This process enhances the stability and durability of the wood by crystallizing its cambium and protects it from shrinking and swelling.”

Typically, during thermal modification, timber is heated to over 180 degrees Celsius, and the wood’s moisture content is lowered to around 4 - 6%. This stops fungal and insect decay as the baking seals the wood making it less likely to buckle, split or move. During the project, AHEC were able to do some fire testing to prove that TMT tulipwood could be fire treated and provide adequate protection on a multi-storey building.

The external thermally modified tulipwood louvres have a high-quality smooth finish that does not require sanding, treatment, or need for servicing. As the building has been built to be demountable, the louvres can be removed and repurposed at the end of the scheme’s life. With this type of timber, one can machine and profile it after having treated it. This is a huge advantage because one can accurately cut sections of it.

The Black & White Building has been designed to encourage interaction and collaboration, enabling people to connect through a variety of spaces in multiple ways. Lounges of various sizes and layouts are found throughout, as well as plentiful break-out areas and pockets of outdoor space, culminating in a decked rooftop terrace offering cityscape views.

cross-laminated timber (CLT)

To maximize natural light in the building throughout the day, a lightwell runs the full height of the building from the rooftop terrace down to a courtyard.. Overall, the building is home to 28 offices of various sizes, 6 meeting rooms, focus booths, and break-out areas, 94 bike storage spaces and showers. On the lower-ground floor is a dedicated yoga and barre studio, which will host wellness activities, yoga, meditation, etc.

The Black & White Building represents a proof of concept that can inspire and encourage the wider architectural community to adopt carbon-minimal construction methods and engineered timber materials. In the long term, it is a call to kickstart a new era of architecture, founded on low-carbon construction, circular thinking, and natural materials.