Demolition is the default ending of almost every building, and it is a strange ending when you think about what goes into one. A mid-size office contains thousands of tonnes of steel, timber, glass, and stone, most of it still structurally sound on the day the excavators arrive. The circular economy has an answer to this waste, and it is less glamorous than most sustainability stories. Buildings that can be taken apart have to be put together with connections that can be undone. In practice, that means the bolt, one of the oldest pieces of hardware in construction, is becoming one of the most consequential design decisions in contemporary architecture.
Why Buildings Became Impossible to Take Apart
For most of the twentieth century, construction moved in the opposite direction. Cast-in-place concrete fuses structure into a single mass. Welding turns two steel members into one. Adhesives bond insulation to membranes, membranes to boards, boards to frames, until a facade becomes a laminate that no one can separate into its ingredients. Each of these techniques won on installation speed or structural performance, and each of them quietly decided the building’s end of life decades in advance. A welded connection is cheaper on Tuesday and unrecoverable in 2065. When a composite building comes down, the materials come down as mixed rubble, and mixed rubble is worth almost nothing. Downcycling into road base is usually the best available outcome.
How a Reversible Connection Actually Works
A bolted joint does the same structural job as a weld through a different mechanism. Tightening the bolt stretches it slightly and clamps the connected parts together, and it is this clamping force, not the bolt body itself, that carries most of the load. The mechanism matters for circularity because it is entirely reversible. Loosen the bolt and the two members separate in the condition they arrived in, ready to be craned out, tested, recertified, and used again. Steel sections recovered this way can go back into new frames with a fraction of the carbon cost of new production, which is why reuse protocols for structural steel have become one of the more active corners of construction research.
Making that work at building scale takes more than swapping welds for bolts. Connections have to remain physically reachable after fit-out, which affects how services and finishes are detailed. Joints benefit from standardized sizes so that a component removed from one grid fits another. Dry assembly has to replace wet trades wherever possible, since anything poured or glued becomes a one-way decision. And every connection needs a record of what it is, where it sits, and what it was designed to carry, which is where material passports enter the picture.
The Buildings Proving the Point
This is no longer a theoretical exercise. In Amsterdam, the Circl pavilion built for ABN AMRO in 2017 was designed from the first sketch to be dismantled, with a timber structure assembled dry and detailed so that major components can be removed and reused. A short drive away in Driebergen, the Triodos Bank headquarters by RAU Architecture, completed in 2019, is often described as the world’s first fully remountable large timber office building, held together by a reported 165,000 screws and documented piece by piece in a digital material register. Its architect, Thomas Rau, popularized the idea behind that register: a building is not an object but a material depot, and the depot needs an inventory. Platforms such as Madaster now maintain those inventories commercially, recording what a building contains so its parts keep an identity and a value.
The Rulebook Catches Up
What was a pioneering position a decade ago is turning into regulatory baseline. The European Union’s revised Construction Products Regulation, Regulation (EU) 2024/3110, entered into force in January 2025 and begins applying in January 2026. Among its instruments is the digital product passport for construction products, a machine-readable record covering composition, environmental performance, and instructions for dismantling and reuse. The direction of travel is unambiguous. Information that reuse depends on, the kind that demolition contractors could never reconstruct after the fact, will increasingly travel with the product from the day it is made. For architects, that shifts design for disassembly from an ethical preference to something clients will ask about in the brief.
Factory Discipline for Joints Meant to Outlive Their First Building
There is a technical fine print to reversibility that architecture is only beginning to absorb from manufacturing. A bolted connection intended to be opened in forty years has to be made correctly today, at a known and recorded clamping force, because an over-tightened bolt may be stretched beyond reuse and an under-tightened one invites the joint to work loose long before any planned disassembly. Vehicle and machinery factories solved this problem years ago with tightening systems that control torque and rotation in real time and log every joint they close. Companies such as Atlas Copco ITBA built their business on exactly this kind of controlled, documented assembly, and as construction moves toward factory-built modules, the same discipline is arriving on the building side. A logged joint is a joint the next owner can trust.
This is also where design for disassembly meets the broader industrialization of building. Prefabricated and modular construction, part of the wider shift explored in RTF’s coverage of innovative approaches to future architecture, already relies on repeatable, bolted, dry connections because modules must survive transport and craning. A module that can be installed cleanly can, with modest additional care, be uninstalled cleanly. The two agendas reinforce each other.
Designing for the Second Life
For practitioners, the working checklist is shorter than the theory suggests. Keep structural connections mechanical and reachable. Prefer standard bolt sizes and repeating connection details over bespoke ones. Treat anything glued, welded, or poured as a permanent decision and make it consciously. Record the building as you make it, down to the connection level, so the inventory exists when someone finally needs it. None of this requires new technology, and that is precisely the point. The circular building of 2050 will probably not be held together by an exotic material. It will be held together by ordinary bolts, tightened carefully, written down, and waiting to be undone.
