At SEPAR, we believe that reuse in construction is not a futuristic concept — it’s already happening within conventional demolition workflows. Our demolition tracking platform Separ Demolition Map shows that the main mined elements are concrete structures, accounting for about 3/4 of the total potential environmental impact.

A recent site visit to our implementation partner Groupe Orllati SA’s demolition operations, guided by Didier Aeby, reinforced this idea: demolition companies are already performing key steps needed for material reuse. The next step is not about introducing reuse anymore but about making it more efficient and scalable.

Dismantling a single floor takes approximately two weeks, generating around 700 cubic meters of concrete. The key factor in achieving efficiency is the strategic use of cutting techniques that allow for precise material removal without unnecessary destruction. Structural slabs and walls are cut using diamond saws, following a predefined 7×1.5m grid. The grid ensures uniform segment sizes, simplifying handling and transport.

Image: Diamond saw used for precise cutting of concrete slabs and walls. (SEPAR, 2025)

Before initiating cutting operations, structural reinforcement is mandatory. These reinforcements provide stability during dismantling and ensure the safety of workers operating on-site.

Image: Temporary support structures are installed before cutting to prevent unintended collapses. (SEPAR, 2025)

Before any demolition work begins, core drilling is performed to extract material samples. These samples, typically Ø8×16 cm, are sent to external laboratories for density and strength analysis. The testing process, which takes approximately 2-3 days, provides data on the composition of the concrete.

Image: Concrete samples are made to test concrete characteristics. (SEPAR, 2025)

Understanding the density of the concrete is necessary for preparing accurate pricing calculations. Contractors use these results to estimate labor requirements, tool wear, and the total timeframe for dismantling.

These same tests are used for assessing the suitability of concrete elements for reuse. While demolition companies currently conduct these tests solely for dismantling evaluation purposes, they already generate the data required for reuse evaluations.

Image: Core drilling machine — for extracting concrete samples for testing. (SEPAR, 2025)

Concrete slabs are marked carefully before being cut to ensure consistency in segment dimensions. The cutting process involves specialized saws with guiding rails to maintain straight cuts, avoiding deviations that could affect subsequent handling.

Image: Marking of the slab and fixing of the guide rail. (SEPAR, 2025)

Pneumatic-powered saws are used for horizontal elements, offering high cutting force suitable for thick slabs. The pneumatic system ensures stable operation with minimal overheating.

Image: Pneumatic Saw – for cutting horizontal concrete structures. (SEPAR, 2025)

Pneumatic-powered saws are used for horizontal elements, offering high cutting force suitable for thick slabs. The pneumatic system ensures stable operation with minimal overheating.

Accurate cutting also plays a role in determining whether concrete elements can be salvaged. If slabs are cut according to standardized sizes, their reuse potential increases. The cutting grid used in demolition already supports this need, as it ensures uniform sectioning.

Image: Pneumatic Saw – for cutting horizontal concrete structures. (SEPAR, 2025)

Once cut, concrete elements are ready to be lifted by cranes and transported off-site. The previously made circular holes are used for carrying the elements. This method is the safest and avoids breaking the crane chain. For reuse, it is important to design a new chain attachment mechanism or adapt the holes for the new purpose.

Image: Chain attachment to a concrete element for transport. (SEPAR, 2025)

The saw passes over the concrete element twice. The first pass creates a shallow guide groove which ensures that the saw runs smoothly.

Image: Chain attachment to a concrete element for transport. (SEPAR, 2025)

During the second pass, the crane lifts the concrete element while cutting to prevent the saw from clamping. At this time, the saw cuts through the element.

Image: Lifting of the cut concrete element. (SEPAR, 2025)

Currently, most of these elements are sent for crushing and recycling. However, nothing prevents them from being directly reused in new construction — except for process inefficiencies and a lack of streamlined logistics.

Image: Transporting a concrete wall. (SEPAR, 2025)

In February 2025, cutting a reinforced concrete slab costs ~155 CHF / m2 for a thickness of 150-200mm. This means that the price of a 7×1.5×0.2m slab is 527 CHF. At the same time, new in-situ concrete production will cost 630 CHF per slab, making reuse 16% cheaper than the new production. This figure can be increased to 40% with the industrialization of the approach.

Currently, concrete from demolished buildings is sent for recycling. However, scientific studies show that recycling produces CO₂ emissions close to those of new concrete production (Glias, 2013). Despite the energy and resource intensity of recycling, it remains the default option due to industry inertia.

A moment before cutting, these materials were part of a functional structure, and their properties remained unchanged. After cutting, they remain the same structural elements—nothing has changed. The process is clear, the costs are defined, and the environmental impact is the lowest possible. There is no valid reason not to prioritize reuse.