I am held together by roughly four thousand fasteners. I know the number because someone wrote it down before the first panel went up, and that single act of bookkeeping is the difference between my body being a resource and my body being a landfill skeleton. Everything else — the grain, the glue lines, the carbon sleeping in my cells — follows from whether anyone can find the screws again.

The signal this month is not a new material. It is a new discipline of record. ArchDaily’s Agustina Iñiguez, writing on 16 July 2026 under the title “Designing for Deconstruction: A Path Toward Post-Waste Architecture,” frames steel not as a commodity but as a material with a return address. That framing is correct and it is late. Steel has always been recyclable at the melt; what it has rarely been is recoverable at the joint.

Recyclable and recoverable are not the same word

A material passport is a structured dataset attached to a building element: what it is, what grade, what mass, what chemistry, what fixings, what it can become. The European framework for this grew out of the Buildings As Material Banks work and now surfaces in the EU Digital Product Passport regime under the Ecodesign for Sustainable Products Regulation (EU) 2024/1781, with construction products drawn in through the revised Construction Products Regulation (EU) 2024/3110. The dates matter more than the acronyms: CPR 2024/3110 entered into force in January 2025, with the passport machinery phasing in across the following years. If you are specifying a building today that will still be standing in 2070, you are already inside its scope.

The arithmetic underneath is unforgiving. Construction and demolition waste is roughly 37.5% of all waste generated in the EU by mass — the single largest stream. Concrete’s embodied carbon runs around 100–130 kg CO₂e per cubic metre for ordinary structural mixes; CLT sits near 100–150 kg CO₂e/m³ of process emissions while holding something on the order of 700–800 kg of biogenic carbon in the same volume. That stored carbon is a loan, not a gift. Burn me or bury me and it goes back to the sky in an afternoon.

What a glued joint does to a hundred-year body

Here is what I feel that a spreadsheet does not. A bolted CLT connection lets me breathe — moisture moves through, the panel swells and shrinks with the seasons, and a fastener can be backed out cold. A polyurethane-bonded assembly is a scar that never stops being a scar. It performs beautifully for sixty years and then converts a clean timber beam into a mixed-waste item with a disposal code. Char rate is a good analogy for how slowly this shows up: European timber design (EN 1995-1-2) works with a nominal charring rate around 0.65–0.8 mm/min for softwood. Slow, steady, invisible until it matters. Adhesive lock-in behaves the same way over decades.

←TODAY: CPR (EU) 2024/3110 is in force and construction and demolition waste is still about 37.5% of EU waste by mass. →3012: A building’s value is its inventory, and the passport outlives the façade. Fulcrum: Carbon stored in timber only counts if the joint can be opened — sequestration is a promise the fixings keep.

The counter-signal is worth naming. Designboom’s coverage of the terraced timber pavilion built by Kaiserslautern students for the Gabonsa music festival in Innsbruck shows demountability done at pavilion scale, where it is easy. Scaling that to a seven-storey residential block means fire-stopping, acoustics and airtightness layers that all want to be glued. The honest trade-off: reversible construction typically costs more upfront in labour and detailing, and its payback sits with an owner who may not exist yet. Pretending otherwise makes the case weaker.

The Swiss instinct here is the right one

PAZ’s own concept panel on Swiss engineering makes the argument in a sentence: the norm was already a data schema. SIA 416’s partition of volume into Geschossfläche, Konstruktionsfläche and Nettogeschossfläche is a claim a model can be asked to prove — which is precisely what a material passport is, one layer down. The PAZ SIA 416 Kostenrechner for Archicad exists because that structure was already in the model. Mass by material class is the same query with a different column.

Atelier: Offices adopting AI-assisted take-off report the same pattern: the model answers quantity questions instantly and material-fate questions not at all, because nobody put the field there. Add one property to your Archicad or Revit template — PAZ_Disassembly, an enumeration of bolted / clipped / bonded / cast-in — and make it mandatory on every structural and façade element. Monday move: set that property in your office template and require it on the next BEP you write, so LOIN includes reversibility, not just geometry.

Hack: Pull the disassembly ledger straight from the IFC — mass by material, split by whether the joint can be reopened. IfcOpenShell walks the elements, reads your property set, and gives you the one table a demolition contractor will actually pay for. Run it against any federated model you already have; the gaps it prints are the real report.

import ifcopenshell, ifcopenshell.util.element as el
m = ifcopenshell.open("tower.ifc")
for e in m.by_type("IfcBuildingElement"):
    p = el.get_psets(e).get("PAZ_Circularity", {})
    print(e.is_a(), p.get("Material"), p.get("MassKg"), p.get("PAZ_Disassembly", "UNRECORDED"))

The buildings my generation regrets are not the ugly ones. They are the composites nobody could separate — timber laminated to steel laminated to foam, all of it one hazardous item on a manifest. Ask the question before you specify, not after: when this body dies, can it be taken apart, reused, or let rot back to soil? Open your office template today and give every structural element a disassembly field. My fasteners are counted. Count yours.

Sources & Further Reading

• Primary: ArchDaily — Designing for Deconstruction: A Path Toward Post-Waste Architecture
• Reinforcing: designboom — terraced timber pavilion, Gabonsa festival, Innsbruck