Retaining structures and reusing components can preserve more value than crushing them for aggregate, but the decision depends on surveys, structural evidence and the next project’s requirements.
Keep the building before recovering its materials
The most consequential circular construction decision may happen while a building is still standing. Retaining a usable frame avoids the need to extract, transport and qualify its individual components for another site. Once demolition begins, the available choices narrow. A concrete beam that could have carried another floor may become aggregate instead.
London’s 1 Triton Square illustrates the scale of retention within a completed redevelopment. Arup reports reusing 35,000 tonnes of concrete and 1,900 tonnes of steel, alongside 3,300 square metres of limestone. Strengthening and reuse strategies allowed three additional storeys and a 70% increase in floor area. Those figures describe the engineering team’s project, rather than an outcome available to every existing office.
Retention must still satisfy the proposed use. Floor loads, foundations, fire performance, accessibility and building services can constrain adaptation. The important comparison is between feasible options for delivering the required space, with strengthening and operational performance included. Declaring a structure obsolete before investigating those options can discard both material and the engineering work already invested in it.
Recovery rates can conceal lost function
When retention is impractical, component reuse and material recycling offer different forms of recovery. Reusing a slab preserves its geometry and potential structural function. Crushing it preserves a mineral resource but loses the manufactured element. Recycled aggregate can replace suitable primary aggregate; it does not, by itself, remove the need for a binder when making new concrete.
The European Commission’s updated 2024 construction and demolition waste protocol places pre-demolition audits, identification of hazardous materials and reuse potential, selective demolition and quality management within the same workflow. These are practical guidelines for organising recovery, rather than a declaration that everything identified in a building is suitable for reuse.
A project therefore needs more than a single diversion percentage. Retained structure, components reused on site, components supplied elsewhere and material recycled should be reported separately. Otherwise, a heavy stream of crushed concrete can dominate the headline while recoverable doors, steel members or façade elements are lost. Each route has a role, but they preserve different things and should remain visible in the accounts.
Concrete reuse requires a structural argument
EPFL’s RE:CRETE prototype demonstrated an alternative to crushing cast-in-place concrete. Researchers cut 25 blocks from existing walls and assembled them into a post-tensioned arch spanning ten metres. Mortar joints accommodated dimensional variation. The team assessed concrete strength using rebound-hammer measurements and loaded the completed structure to its design live load while recording deflection.
This was a specific design and test programme, not blanket validation of salvaged concrete. The bridge geometry, loading and assembly method were selected together. That is central to reuse engineering: the available material influences the new design, and the evidence must address that design’s demands.
At a different scale, the European ReCreate project developed quality-management procedures for reclaimed precast elements. Its published account reports acceptance of the process by building inspectors in Tampere and Helsinki as part of site-specific product approval. It also describes assessing deterioration, harmful substances, material properties and structural capacity. Local acceptance is a meaningful demonstration, but does not amount to automatic approval throughout Europe.
A catalogue is not a structural specification
Steel presents its own route from recovered member to usable product. The Steel Construction Institute’s second edition of P427, published in June 2024, describes investigation and testing to establish material characteristics, together with design advice for reclaimed steelwork. Its responsibilities for holders of recovered steel include identification, assessment and control procedures.
A marketplace entry listing a beam’s dimensions cannot replace those tasks. The design team needs sufficient evidence about the member’s properties and condition, while the supplier needs to preserve its identity through storage and fabrication. Existing holes, connections, surface treatments and damage can affect how it is used. The required investigation depends on the product and application.
The implication for digital inventories is straightforward. Photographs and dimensions help a designer find a candidate; verified technical information helps decide whether it can be specified. Availability dates, location and ownership also matter. A perfectly described member that cannot be released before the receiving project’s installation date is not yet a workable supply.
Information should follow the physical item when batches are separated. A reused component’s commercial value can fall sharply if its inspection record becomes detached from it, even when its physical condition has not changed.
Time and storage shape the market
New construction and deconstruction rarely run to identical calendars. A contractor may need to clear a site months before another project can accept the recovered materials. Storage can bridge that gap, but introduces handling, space and financing costs. A reuse business must decide which items justify those costs and how long to hold them.
The Interreg PREUSE project has documented 18 reuse centres visited between June 2024 and June 2025 across six European countries. Its study examines storage, staffing, preparation, packaging and financing. The project has also produced a draft strategy for public reuse centres, drawing on those cases and workshops with more than 60 public authorities. These are operational observations and guidance, not evidence that every centre has a profitable business model.
Demand aggregation could make such facilities more useful. A public estate planning several refurbishments can identify recurring needs for suitable fittings or components before they arise. However, collecting material without a plausible user merely transfers a disposal problem into a warehouse. Acceptance rules and an inventory review process are as important as floor space.
Flexible interiors offer a different opportunity
Structural frames are only one part of the circular construction market. Interiors change on shorter commercial timescales, creating opportunities to preserve partitions and other components through repeated adaptation. These uses have different performance requirements from a load-bearing slab and should be assessed accordingly.
Empa and Eawag’s NEST Sprint unit opened in August 2021 after a ten-month development period. The 200-square-metre office space used largely recovered materials and components, including demountable partitions. Empa’s account explicitly notes that reuse was not inherently cheaper in the market conditions encountered.
That qualification matters for procurement. Savings on the original item may be offset by survey, cleaning, adaptation or installation work. Conversely, a partition designed for disassembly may offer value at the next change of layout even if it does not minimise the first fit-out price. Comparing alternatives over a stated sequence of uses makes that trade-off visible.
Building owners can support this approach by keeping records of changes and avoiding unnecessary destruction during minor refurbishment. Designing an accessible connection today only creates a future reuse opportunity if the next operator can locate it, understand it and dismantle it safely.
Buy a reuse process with clear acceptance points
Targets can encourage reuse, but their definitions influence behaviour. Rotor’s FCRBE work published a method for reuse and reclamation rates, analysis of 32 completed projects and four live tests examining reuse rates in procurement. The work treats measurement and purchasing arrangements as linked questions.
A practical brief should identify when reclaimed components must be surveyed, reserved, tested and accepted. It should also allocate responsibility if a proposed item fails inspection or becomes unavailable. Allowing a designer to consider several suitable dimensions can widen the usable stock; fixing every dimension before searching may exclude otherwise sound components.
European circular construction can develop around these decisions: investigate retention first, preserve components where their properties and the next use align, and recycle material that cannot safely or practically retain its function. Success means carrying useful buildings and products into another period of service, with evidence that designers, contractors and owners can act on.
A useful project review would record the components considered but rejected, alongside the reasons: inadequate evidence, unsuitable geometry, excessive intervention or incompatible timing. Those failures can guide the next procurement brief. Reporting only successful reuse leaves the industry without the information needed to remove recurring barriers and distinguish technical limits from avoidable planning decisions.
