Katherine Adams and Connie Spoor talk about the circular economy and construction, and practical strategies for making reuse a priority on housing projects and self-builds.
Interview with Katherine Adams and Connie Spoor
Katherine Adams co-founded Reusefully, a partnership offering advice on the circular economy and the built environment. She is also the technical director for the Alliance for Sustainable Building Products (ASBP). Connie Spoor is a self-builder working on a low embodied carbon Passivhaus and making reuse part of the process.
The existing dwelling was in extremely poor condition
Materials for reuse came from Connie’s site
Connie’s project started with demolishing an existing house and barn. She and her husband wanted to reuse anything they could from the demolition – in particular, local limestone. They chose their architect, David Holland, based on shared values towards reusing materials. All three of them looked out for things that could be reused and incorporated them into the design.
Connie acknowledges it was a more ‘informal’ approach than Reusefully takes. But because she knew what was being demolished, she could make sure it was factored into the design.
A good place to start is with a materials inventory
Katherine works on all types of buildings. The process is always the same, and starts with a materials inventory to understand what is in the building. This involves gathering information (like architectural drawings), though often there isn’t much available.
Then a site visit allows for a more detailed analysis, albeit without carrying out intrusive investigation. That can result in some guesswork, especially where there are no detailed plans or specifications. Lack of information is particularly difficult when it comes to understanding the structural performance of materials: what they were designed to do, and what they might be capable of when being reused.
Everything goes into a big spreadsheet to work out dimensions and volumes. From that, a report of recommendations is produced. Reuse is the preference, then recycling. Recycling is still valid, but the key is to try and find better recycling routes.
Stones were reused in the gabions
Different materials are reused to different extents
All materials are useful in some respect, but some are easier to reuse than others. Katherine doesn’t see a lot of timber being reused structurally, because of the associated risks in terms of knowing how it will perform.
There’s an active market in reclaimed timber, usually for internal uses. You don’t always know how timber has been installed and fixed; for example, it can be difficult to remove bitumen from parquet flooring. But there are people finding innovative ways to reuse timber.
Katherine knows a company that takes joists and cuts them into floorboards. An organisation called Community Wood Recycling takes wood from sites, regrades it and sells it on. The alternative is chopping up existing timber for panel board or biomass, which Katherine describes as, “a little bit soul destroying.”
For structural uses, timber could follow the route of the steel industry, which has come together and created a protocol for reclaiming steel, CE marking it, and ensuring it can be insured and warrantied for future projects.
Concrete reuse is tricky. Because it is so cheap, it’s not viable to re-test and re-certify existing material. There are too many processes to go through.
A lot of older brick is reused, because it has value. Newer brick doesn’t have the same value. Bricks are relatively cheap, so there’s little incentive to reuse them – especially when they’re bonded with Portland cement, which is really difficult to remove.
Plastic is particularly hard to recycle
In terms of recycling plastic, two or three recyclers have closed down recently. Even with government policies in place, there simply isn’t a market for recycling plastic. Construction sites don’t tend to produce much plastic waste, and it isn’t valued enough to segregate or clean. To avoid landfill tax, it usually goes to a waste transfer station where it is turned into pellets and burnt for energy.
Embodied carbon savings are a big driver for reuse
Katherine cites a residential refurbishment project that used reclaimed steel beams, saving 3 tonnes of embodied carbon and reducing steel costs by around 40%. Another advantage of reusing existing steel was that they sourced it in just a few days, which reduced lead times significantly. Find out more with the ASBP’s case study.
Hazardous materials affect reuse or recycling potential
It can be difficult to know if hazardous materials, like asbestos or lead paint, are present in buildings. If the available information is limited then it can lead to some surprises. Reuse or recycling potential might only become clear if materials are tested, which comes at a cost.
An important first step that Connie took was to remove anything that would make the rubble unusable, such as plastic windows and all the wiring, before demolition started.
Communication with demolition contractors is essential
Connie explained to the contractor what she wanted to achieve, and they separated brick and stone as they worked. Connie’s husband sorted a lot of the metal, separating copper, lead and some steel, for scrap – all of which should be reused or recycled.
Katherine’s experience is that demolition contractors will recover and recycle as much as possible, because they make money out of materials and they don’t want to pay landfill tax. Recovering materials for reuse often boils down to extra physical effort, whereas most demolition is very mechanised.
Katherine has found the best approach is to try and nudge companies towards doing a little bit more than they usually would. For example, instead of crushing glass and putting it with aggregate, sending it back to a glass manufacturer as part of a closed loop system.
Material value is key to making reuse viable
Connie recognised that if there was value in the material, then it was worth reusing. For example, buying new stone would have been expensive, and she doubts it would have been possible to find anything as nice to fill gabions with. She describes that as, “quite an easy win.”
Large stones are also being used for cladding on the gable end. That has made financial sense, especially as Connie’s husband is cutting the big stones down to size and installing the smaller pieces as cladding himself.
Unfortunately, material value can have its downsides, and a bagful of lead was stolen from site.
Material exchange platforms are a useful resource
For homeowners and individual sites, the volume of material generated often isn’t big enough for waste management companies to consider it viable. Material exchange platforms are a way to both source and pass on materials that have reuse potential. Although reuse still isn’t very common, the development of exchange platforms is a growing area.
Examples include:
- the ASBP’s list of digital platforms and physical hubs;
- the ReLondon website, helping to improve resource management in the London boroughs; and
- Salvo, an online directory and marketplace for reclaimed materials.
Some platforms are focused on commercial buildings. For homeowners and self-builders, the likes of Facebook Marketplace, eBay, Freegle and Gumtree will always be useful. There are also websites that specialise in second hand kitchens, for example.
Storage of materials is a barrier to reuse
In an ideal world, materials would be removed from one site and used on another straight away. There is usually a lag between removal and reuse, however, and that means having to store materials somewhere.
Buildings need to be designed with reuse in mind
Katherine says that, “a lot of the circular economy is about designing for circular economy outcomes.” Most existing buildings weren’t designed with material recovery in mind.
Industry is working on designing new buildings for disassembly and deconstruction. A lot is to do with fixings, and making sure they are reversible fixings like screws and bolts. Nails are okay, but glue should be avoided. When thinking about mortars, lime is better than cement.
Alongside design, a good set of information is essential: keeping drawings, a record of what has been done to the building, who the original manufacturers and suppliers were. All of this really helps reuse. Currently, there’s quite a move towards material passports, which record the materials that have gone in, what certification they’ve got, what their life expectancy is, and who the manufacturer is.
All of this information adds to the certainty about being able to reuse the materials, but how you keep that information with the building is the challenge – especially in housing.
Creativity is a big part of reuse
Katherine advises keeping some flexibility in the design, and shifting mindset to see a building as a ‘material bank’. Rather than having a preconceived idea of what the design will look like, be open to using materials that are already there, or materials that you can find in the various marketplaces.
Not everything has to be reused or reclaimed. But anybody self-building or retrofitting can think about the materials they’re using and where they’re coming from. Connie has done that, and her next step is to finish the interior of her home with as many reclaimed materials as possible.
Further inspiration recommended by Katherine:
‘Housing Reclaimed’ book review
Habitat for Humanity ReStore:
Find out more
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