Spotted: The population of Freetown, Sierra Leone, is set to reach 2 million by 2028. As the population rises, urban sprawl is threatening the forested, mountainous areas outside the city. Around 70 per cent of Freetown’s trees have been cut down, and the city is already experiencing negative effects – such as devastating floods and landslides – from the loss of these critical ecosystems.
To reverse this trend, the city council has introduced a scheme, called Freetown the Treetown, which encourages residents to plant and maintain new trees and mangroves, using seedlings supplied through local nurseries. Progress is tracked using a mobile app, and, as an incentive, the initiative pays city residents for each tree they plant, maintain, and monitor.
The mobile platform creates a unique geotagged record for each planted tree. Growers must then revisit the tree regularly to water and maintain it, and to verify and document its survival. In exchange, they receive per-tree micro-payments through the platform every two months over the first three to five years of the tree’s life (which is when trees need most maintenance).
To finance the programme, each tree is ‘tokenised’ and the tokens are sold to corporations and institutions to help them meet their climate and corporate social responsibility (CSR) targets. The money raised then goes to maintaining the programme. Freetown the Treetown is a 2023 Earthshot Prize finalist in the ‘Protect and Restore Nature’ category.
Tree planting is an important tool for reducing the impact of climate change. Some recent innovations in forestry that could help with this include providing indigenous communities with funding for forest stewardship and improving tree health by restoring fungal networks.
Spotted: In the UK, slightly more than 80 per cent of consumers say they prefer eco-friendly packaging, and this growing trend of favouring sustainably packed items can be seen across the globe. Using recyclable materials is one way brands are becoming more sustainable, but often this isn’t enough. For example, a lot of recyclable materials aren’t disposed of correctly, so cannot be recycled properly.
Reusable packaging is an alternative solution that is gaining momentum. But the technology needed to sort and clean packaging for future reuse is not yet firmly established. Seeing a gap in the market, London-based startup Again has created an automated cleaning service that makes it possible for brands to reuse their packaging materials.
Called CleanCells, the micro-factories use robotics to bring reuse technology to businesses. The facilities service multiple organisations in each location, helping to keep costs low enough for small and medium enterprises to afford the service. And Again purposefully matches the price of its services to that of single-use plastics and other packaging in order to encourage the take-up of its circular system.
The CleanCells are situated near or within logistics hubs to reduce transport costs and each can clean up to 500,000 units of packaging per month. From visual inspection to in-line microbiological and allergenic monitoring, the company’s quality assurance ensures that food-grade packaging remains safe to use. Meanwhile, an accompanying software platform allows companies to manage and monitor their packaging supply chain.
Springwise has spotted other innovators in the archive working to turn single-use packaging into a circular model, including one for takeaway lunches and another cutting single-use food waste across US universities.
Spotted: Every year, between 8 to 10 million metric tonnes of plastic end up in our oceans. Countries in Southeast Asia are among the major offenders – many lack the infrastructure to collect and process plastic waste. Vietnam, which only recycles around a third of its plastic waste, is one of these. But a startup called ReForm Plastic is aiming to change this, as well as improve the lives of Vietnamese waste pickers – who are largely women.
ReForm focuses on repurposing different types of waste plastic into moulded plastic products such as: construction tiles, tables, chairs, waste bins, playground equipment, and holds for rock-climbing walls. However, the startup is also repurposing the waste system by transforming existing collection centres into small production facilities.
The small recycling centres are equipped with efficient low-cost machinery, collection and processing equipment. Each centre is partially locally owned and managed, but generates products that are centrally purchased and distributed by ReForm.
ReForm already has four factories in operation in Vietnam – and is building six more in partnership with organisations in Thailand, Bangladesh, Laos, Mozambique, and the Philippines. In addition to providing work for thousands of workers, the circular system also formalises a large proportion of the informal waste sector.
One way that innovators are tackling plastic waste is by collecting it and turning it into new products – reducing waste as well as the use of fossil fuels to make virgin plastics. Springwise has spotted a startup making backpacks from recycled plastic and a refillable and decomposable replacement for plastic pill bottles.
Mass timber could become a key tool in reducing waste from the construction industry, GXN partner Lasse Lind tells Dezeen in this interview for our Timber Revolution series.
GXN was founded in 2007 as the research arm of Copenhagen-based architecture studio 3XN.
GXN looks at circular and low-carbon design, behavioural design – including the social aspect of buildings – and technologies that can help the industry transition to a more sustainable future.
Use of timber “exploded”
Its use of timber has “exploded” recently, with around half of its buildings now having a significant element of wood in their structure, up from almost none five years ago, Lind said.
“We’ve always been very interested in materials and material technology,” Lind told Dezeen.
“Our material focus has evolved to change over the years and now we’re extremely focused on recyclability, recycled content, low-carbon, natural biogenic materials – that is our absolute focus.”
Above: Lasse Lind is a partner at GXN. Top: A CLT-framed hotel on Bornholm is among the studio’s projects. Photo by Adam Mørk
The majority of the studio’s work at the moment is in mass timber, which Lind says has many advantages over other building materials.
“The first one is obviously lower carbon, which is a big advantage, and the fact that it’s kind of regenerative as a material,” he said.
“There are other aspects as well, which are related to build-ability,” he added. “Timber tends to be lighter than, for example, concrete construction. So you need less transport and, in principle, fewer crane lifts.”
Timber helps you “close the loop on waste”
The fact that everything is prefabricated when it comes to mass-timber construction also means it is possible to work with more precise tolerances and cut down on waste, according to Lind.
In a recent project, a full-timber hotel extension on the island of Bornholm, Denmark, the studio even used offcuts from the cross-laminated timber (CLT) used for the building to create furniture and furnishings.
“You don’t have a lot of waste, potentially, in the production,” he said. “Especially if you think about it like we did in the prototype on Bornholm, where we used all the offcuts for furniture – you can actually close the loop on waste in the production chain a bit.”
The studio’s use of timber has “exploded”. Photo by Paul Casselman
As part of its research in this area, GXN is also experimenting with using offcuts from CLT boards as slabs in its buildings.
“You would have to live with the fact that it’s different thicknesses and you would have to look at the grid because if it’s offcut materials, you cannot get everything in eight metres,” he said.
“You have to have some substructure to accommodate a variety of sizes, so you need to spend a little bit more energy on the substructure but then you can actually use these offcuts as actual slabs.”
At the moment, the addition of concrete to the slabs is one of the things that makes it hard to design fully reversible timber buildings.
“In larger timber structures, where you have slabs, the standard practice is to cast everything out due to sound and vibration,” Lind explained.
“So essentially, if you have a timber slab, you cast a screed of concrete on top, and that actually messes up the reversibility of a lot of the structure,” he added.
GXN has attempted to create buildings that use alternatives to concrete slabs, including a version that saw the studio use egg crates filled with sand instead of the slabs.
“What we tried to do on the project on Bornholm is to have these crates and fill them with granite dust, waste production from granite, but the engineers wouldn’t sign off on it, unfortunately, so we weren’t able to do that for that project,” Lind said.
“But we are doing a building right now where we are getting rid of that concrete screed,” he continued.
“It’s something we’re always aware of when we’re building with timber – if we can get away from that detail, we’d like to, because it’s a small detail but it messes up the reversibility of the whole structure.”
Carbon budget “structures the discussion”
Lind believes that in the future, we will see a lot of hybrid timber systems as the industry figures out when wood is best to use.
“We [need to] figure out what timber is really good for, what concrete is really good for and what steel is really good for,” he said.
“The approach should be to minimise the use of concrete and steel, but there are just parts of a building where [those materials] makes more sense,” he added.
“I’m very interested that we use materials where they are best, and I think there are a lot of places where we could easily replace concrete or steel with timber.”
The Lemvig climate centre features a wavy wooden facade. Photo by Adam Mørk
To help minimise carbon emissions, GXN sets carbon budgets for each of its projects that vary depending on the type of project and country it’s built in.
“The one thing we always try to do is bring a carbon budget, because it puts carbon up for discussion with every material choice and in that sense, it structures the discussion, like a financial budget does,” Lind said.
As timber buildings become more popular, Lind believes that as well as having an impact on carbon emissions, the material will also impact the way that buildings look, behave and feel.
“I think we will begin to explore, as designers, the vocabulary of what we can do, which I think will be very interesting,” he said.
“I don’t think it will be the same as architecture was 50 years ago when we kind of discovered the computer, but if you think about it, there are a lot of really creative half-timber buildings in Europe that have all kinds of weird ornaments and shapes and forms,” he added.
But though the use of timber and mass-timber is becoming more popular, there are still challenges facing architects when designing timber buildings. One of these is conveying the safety of the buildings to insurance companies.
“What we’re seeing as a challenge for timber buildings right now is generally insurance, because it’s a different material from what people usually use,” Lind said.
“We often find that insurers need to get on board and understand that it’s different. Because you can secure timber buildings, you can build them in a way where they are safe to operate and they’re safe as an asset, but there is a degree of scepticism from insurers.”
Designers should love timber’s “natural patina”
There are also sometimes regulatory difficulties as fire safety rules are often based on buildings made from steel or concrete.
“Inherently timber structures burn in a different way than steel or concrete does,” Lind said.
“And you can build safely with timber, but the way that you measure and regulate it needs to be different because it’s not steel,” he continued.
“Steel gets extremely hot and then it snaps, timber burns very slowly. It’s just a different strategy, fire-wise, that you need to apply.”
GXN uses a carbon budget for its projects. Photo by Rasmus Hjorthøj
Architects and clients also need to get used to the fact that timber is a living material, which means it will change in ways that concrete and steel buildings might not, he argued.
“There’s a certain degree of natural patina that you should love as a designer,” Lind said.
“You should love the fact that it’s a material that changes over time – it’ll change colour, maybe have some cracks, it’s not going to look the same forever,” he added.
“So there’s some aesthetical considerations that you should be able to take your client through and understand that this is a living material and performs in a different way than an inorganic material.”
The architect believes that we’re only at the beginning of seeing the possibilities of timber and mass timber.
“There are loads of things that you could do even with fairly simple timber construction; there’s a whole field of investigation that we’re getting into which will be very interesting,” Lind concluded.
This article is part of Dezeen’s Timber Revolution series, which explores the potential of mass timber and asks whether going back to wood as our primary construction material can lead the world to a more sustainable future.
