construction · circular-economy · family: the rulebook was written for a world that no longer exists
same slab, four rulebooks
A reclaimed hollow-core slab is waste in Finland, a product in the Netherlands and ambiguous in Sweden — under the same EU directive — and no standard says how many slabs to test before re-using a building's worth
Problem statement
Reusing whole precast concrete elements — hollow-core slabs, wall panels, beams and columns lifted intact from a building being taken down — avoids almost all of the carbon of making new ones, and the EU-funded ReCreate project has been testing it in real deconstruction pilots in Finland, Sweden, the Netherlands and Germany. But its legal-requirements study found that the rulebook was written for new products and disagrees with itself across borders. On waste status: "it is unclear how the EU Waste Framework Directive and its national implementations should be interpreted when it comes to the waste status of deconstructed components intended for reuse: are they waste or not? Some actors consider such components as waste, others argue the opposite, and there is no consensus." Finnish environmental authorities treat deconstructed elements as waste (requiring environmental permits and end-of-waste procedures), in Sweden "it is still ambiguous," Germany has explicit legal routes to avoid waste status, and the Netherlands does not treat them as waste, provided they contain no hazardous substances — "these differences are noteworthy in that all the countries' waste legislation is based on the same EU Waste Framework Directive." On technical approval: "technical requirements for reused elements are presently the same as for new elements," but the properties of a reused element cannot be controlled in manufacture, "documentation about the original manufacture is rarely available," existing assessment standards "have not been devised to consider the reuse of a building's parts in a new kind of assembly," and, in the report's discussion of Germany, "the necessary sample size for testing ... is still the authorities' case-by-case decision." The unsolved problem is a product-approval and waste-status pathway sized to a reused structural element — one that neither the CE-marking regime nor national existing-structure assessment codes were built to provide.
Why this matters
Concrete is used everywhere — in buildings, cities and infrastructure — and the ReCreate blog notes that reuse's climate benefit far exceeds the small offset from carbonation. The new Construction Products Regulation, published in December 2024 and applying in stages from January 2025, concedes the gap in its own recitals: "the second-hand market for construction products is currently not very developed and requirements for construction products which have previously been used vary widely amongst Member States," and used products are to be brought under harmonised technical specifications only through "long-term harmonisation." Until then, approval of reused components stays national. And where deconstructed elements count as waste, as they do in Finland, the environmental-permit bureaucracy, the study warns, "may hinder small or medium-sized enterprises from entering the reuse market and so slow down the circular economy transition of the whole sector."
What’s been tried and why it hasn’t worked
The pathway that exists is national and improvised. In Finland the ministry clarified in June 2022 that reused components are approved by local building supervisors through "construction site-specific approval," but as of the report "it is still unclear how the approval process is conducted for different reused building components — including precast concrete elements." Sweden lacks established procedures, "assign[ing] a heavy responsibility on developers when it comes to proving the technical properties"; the authorities "have not elaborated on which substances should be analysed" for hazardous content, and a sister project (Återhus) has devised potential methods that the report calls "a good basis for further development." Germany and the Netherlands have institutionalised alternatives — German case-by-case approvals and Dutch product certificates from certified bodies — but even there "the special requirements for reused building components add complexity to the planning and approval process and therefore increase the costs of the project." CE marking is not a route: harmonised standards "contain requirements for quality control during manufacture that are not possible for reusable building components" (a Finnish ministry-commissioned study quoted in the report), so "reused construction products cannot normally be CE-marked" (a Danish reused-brick company's voluntary ETA is the exception the report cites). Existing-structure assessment standards (used to check a building in place) set "minimum required testing methods and sample sizes" for the present use, not for redesign of individual elements into a new assembly, so "new kind of standards are required for assessing the properties for redesign of reusable elements, as the current methods may not be safe enough." Waste hierarchy enforcement compounds it: regulatory attention "lies in the stages 3–5 of the waste hierarchy (recycling, recovery, disposal)," so "regulations and market structures are incentivising the building industry towards recycling, rather than reuse." The 2024 CPR opens a door — used products can be covered by future harmonised specifications, and products "directly reused in a construction work" are not treated as placed on the market again and fall outside the regulation — but the regulation only establishes "the possibility to develop dedicated harmonised technical specifications," and no dedicated specification for reused precast concrete yet exists: the report found "regulation on the use of reused elements is missing," and the KTH release on the January 2026 study cited in the Source Notes still says "no clear guidance is available for reusing elements."
What would unlock progress
Two enablers, both within reach: (1) a statistically grounded, element-type-specific sampling and testing protocol for reclaimed precast (how many slabs from a batch to core, hardness-test or load-test, which hazardous substances to screen, how to document provenance) that national authorities and eventually a CEN standardisation request could adopt as the "product category of their own" the study says could be helpful; and (2) an inverted default for waste status — "a product would become waste only if it could not be reused" — implemented through a common EU interpretation. Adjacent precedents: a Danish company's ETA for reclaimed bricks, which the report cites. Two further analogies worth a team's own checking: aircraft-part re-certification (traceability plus condition-based inspection instead of manufacturing QC) and the reused-steel route (SCI P427/P440 and CEN/TS 1090-201).
Entry points for student teams
A structural-engineering team could design and pilot a sampling-and-testing protocol for one element type (e.g., hollow-core slabs from a specific 1970s system), using reliability theory to derive how many elements must be tested for a target confidence, and check it against ReCreate pilot test results where the project has published them. A law/policy team could produce a comparative map of waste-status and product-approval rules for reused precast across EU member states and draft the model interpretation or standardisation-request scope the CPR now permits. A digital team could prototype the provenance-and-test record (a "reuse passport") that would travel with an element from deconstruction survey to permit. Relevant skills: structural reliability, materials testing, EU regulatory law, information systems.
Genes
Structural cousins: stuck the same way, in other fields
Sources
Halonen, T., Räsänen, A., Jonker-Hoffrén, P., Huuhka, S., Malmqvist, T., Al-Najjar, A., Vullings, M. W. F., Wijte, S. N. M., Fischer, J. and Henschel, C. (2023), "Legal and technical requirements in reusing precast concrete," ReCreate project (EU Horizon 2020 GA 958200) Deliverable D8.2, (PDF: ), accessed 2026-08-18; Regulation (EU) 2024/3110 (Construction Products Regulation), OJ L 18.12.2024, recitals 34–36 and Art. 3(20), accessed 2026-08-18 go to source 1 ↗ go to source 2 ↗ go to source 3 ↗
Working notes
Notes made while writing and checking this brief, shown as written. They use working shorthand.
All country findings and quotations are from ReCreate D8.2 (dated March 2023 in text; Zenodo record 2024), read in full on 2026-08-18; CPR quotations are from the Official Journal text of Regulation (EU) 2024/3110 (recitals 34–36, Art. 3(20) definition of "used product") read the same day. D8.2 states its findings will be updated by deliverable D8.3 with pilot experience; D8.3 was not located this session — flag: verify whether Finnish/Swedish approval procedures have since been formalised. Verifier check (2026-08-18): a January 2026 KTH/Tampere study on service-life prediction for reused precast states that a Swedish national standard for reusing precast elements is being drafted (SIS committee) but does not yet exist, and that 'regulations are designed for new concrete and no clear guidance is available for reusing elements' — the gap remains open. Sibling intake brief `construction-low-clinker-concrete-carbonation-durability-proxy` covers the carbonation-rate proxy that also affects reuse assessments. `failure:regulatory-mismatch` under the "no approval pathway" sub-pattern; `failure:ignored-context` because existing-structure assessment standards and hENs are applied to reused elements without accounting for absent manufacturing records and new-assembly redesign. `constraint:installed-base` (regulatory/standards lock-in sub-type): CE marking and hEN quality-control requirements presuppose a manufacturer. `constraint:coordination` was considered and rejected on filter (1) — member-state authorities do not agree on the approach (waste vs. product) — and filter (2), the binding constraint being missing standards/pathways. `stakeholders:multi-institution` passes: national building-supervision authorities own product approval, environmental authorities own waste status/permits, CEN/Commission own harmonised specifications, and deconstruction contractors/developers hold the elements and data — no single actor can create the pathway. `temporal:window` (deadline type): the CPR 2024/3110 empowers the Commission, with the CPR Acquis Expert Group, to decide whether used products are covered by each new standardisation request — the scoping of those requests over the next few years determines whether reused precast gets a harmonised route or stays national. Related collection briefs: `construction-demolition-waste-sorting` (mixed C&D waste) and the round-A rejected `construction-reclaimed-steel-in-situ-property-verification` (steel, since addressed by SCI/CEN documents); this brief is concrete-element reuse, whose steel-equivalent standards do not yet exist. Cross-beat note: overlaps the circular-economy beat's C&D-waste territory; the primary domain here is construction because the barrier is product approval of a structural element, not waste-stream valorisation.
Source type: Self-articulated (EU research consortium documenting the regulatory obstacles to its own pilots)
Verified at intake 2026-08-18: gate (net) + adversarial source check + contested-tag second coding. Verifier re-read ReCreate D8.2 (Zenodo PDF, §5.1–5.3) and Regulation (EU) 2024/3110 recital 34 (OJ text): all quotations confirmed ('no consensus', 'still ambiguous', 'same EU Waste Framework Directive', 'rarely available', 'not devised', 'case-by-case decision', 'product category of their own', 'second-hand market ... not very developed', 'long-term harmonisation'). Note: the 'case-by-case decision' sentence sits in the German discussion in §5.2, following the general statement that new standards are required.
Related briefs (distinct sub-problems, cross-referenced 2026-08-18): `circular-economy-mineral-wool-demolition-hazard-default`, `construction-demolition-waste-sorting`.
Reconciliation 2026-09-30: The whole write-up was read against its sources. The ReCreate report D8.2 was read in full (75 pages) on 2026-09-30 from an Internet Archive copy of the Zenodo file, https://web.archive.org/web/20250117051210id_/https://zenodo.org/records/13829045/files/D8.2%20Legal%20and%20technical%20requirements.pdf, because Zenodo itself refused the request; its citation was checked against the report's own "Cite this document" box and the DataCite record for the DOI (https://api.datacite.org/dois/10.5281/zenodo.13829045). Regulation (EU) 2024/3110 was read in full text from https://www.eota.eu/sites/default/files/files/OJ_L_202403110_EN_TXT.pdf the same day. The ReCreate blog that the text names without a link was read at https://recreate-project.eu/2025/01/15/reusing-precast-concrete-for-a-sustainable-future-evaluating-service-life-carbonation-and-carbon-footprint/ (the post cited by the sibling carbonation brief). Changes: (1) The text said ReCreate "has demonstrated" reuse in deconstruction pilots in the four countries. The report describes deconstruction pilots in all four, but says the pilots' results will come in a later report, and calls the German reuse pilot "planned"; the sentence now says the project "has been testing it." (2) The text said the Netherlands does not treat the elements as waste "at all." The report says they are not considered waste "given that they do not contain hazardous substances"; that condition is now in the sentence. (3) The quotation "not devised to consider" was missing two words; it now reads "have not been devised to consider," as in the report. (4) The sample-size quotation was presented as a general finding. In the report it closes the paragraph about Germany; the sentence now says so. (5) "Concrete is the most-used material on Earth," the list of national precast systems (Finnish BES, Swedish A-system, Dutch VAM, East German WBS-70), the 1960s–1980s dating, and "millions of tonnes" reaching demolition age are in none of the three sources. They were removed; the sentence now uses the blog's own opening, that concrete is used everywhere in buildings, cities and infrastructure. (6) The text said the Construction Products Regulation has been "in force since December 2024." The Official Journal copy is dated 18 December 2024; Article 96 says it enters into force on the twentieth day after publication, with some articles applying from 7 January 2025 and most from 8 January 2026. The sentence now says it was published in December 2024 and applies in stages from January 2025. (7) The warning that bureaucracy "may hinder small or medium-sized enterprises" was attached to case-by-case product approval. In the report it is about the environmental permits that follow from waste status in Finland; the sentence now ties it to waste status and names Finland. The claim that "every reuse project must negotiate approval case by case" went further than the report, which says approval is conducted nationally and that the Netherlands and Germany have established routes; it now says approval stays national. (8) The text said the Swedish Återhus methods "remain unadopted." The report says only that they "form a good basis for further development"; the sentence now quotes that. (9) The Danish brick company's approval was called "the rare exception" and later "Denmark's ETA." The report offers it as an example and names a company, not the state; both phrases now follow the report. (10) "On-site reuse" falling outside the regulation is now given in the regulation's own words, products "directly reused in a construction work" (recital 34), and the regulation's own statement that it establishes "the possibility to develop dedicated harmonised technical specifications" was added. The statement that "no dedicated specification for reused precast concrete yet exists" was first taken out as unsourced, then restored by the second reader: the report says "regulation on the use of reused elements is missing" (its Netherlands discussion of structural assessment), and the KTH release of 28 January 2026 on the study cited in the Source Notes, read at https://www.eurekalert.org/news-releases/1114522, says "no clear guidance is available for reusing elements" and that the work is a contribution toward a national standard; the sentence now quotes both. (11) The report does not "call for" a product category of their own; it says this "could be helpful." The wording now matches. (12) Aircraft-part re-certification and the reused-steel documents (SCI P427/P440, CEN/TS 1090-201) are in neither source. They are kept as analogies for a team to check for itself, and the claim that the steel documents "now define testing and declaration" was taken out. (13) The entry point spoke of "published ReCreate pilot data." The report says pilot results will be reported later and does not say any data set is public; the sentence now says to use pilot test results where the project has published them. Confirmed in the sources and left as written: the Source line for both documents (authors, title, year, grant number, DOI; recitals 34–36 and Article 3(20)); every other quotation from the report and from recital 34; the waste-status positions of Finland, Sweden and Germany; the June 2022 Finnish ministry clarification; the Finnish-commissioned study behind the CE-marking quotation; the near-total carbon saving (the report gives a reused element's footprint as 2–7% of a new one); the blog's statement that the climate benefit of reuse exceeds that of carbonation, which it puts at less than 6% of the emissions of new precast construction; and the role of the Commission and its expert group in deciding whether standardisation requests cover used products (Article 4). A second reader went over all thirteen repairs on the same day against the same three sources (D8.2 fetched directly from Zenodo this time), confirmed each against the passage cited, tightened change (7) so that the warning is placed in Finland, where the report puts it, and restored the closing claim in change (10) as described there after locating the January 2026 KTH/Tampere study through the KTH release named above; that release also confirms in substance the two statements the first note takes from the study (a Swedish national standard being worked toward by an SIS committee the authors sit on, and "regulations are designed for new concrete and no clear guidance is available for reusing elements"). The journal article itself was not read. Could not be checked: whether the SCI and CEN steel documents exist under those numbers. Neither title changed. Genes untouched.