Why Not Demolition?
Although it has not been officially established how long a building will last (factors that play a role are the functional, economic and technical lifespan), a ‘default’ value of 75 years is often used for residential buildings and 50 years for non-residential buildings¹.
If we look at the interiors and wall coverings in, for example, the retail sector, we see that this strongly depends on trends. This can mean a lifespan of around 3-5 years for macro trends and even as little as 3 months to 1 year for micro trends².
After the demolition of a building or interior, much of the resulting waste material can be recovered, but in practice much of this is recycled into a less valuable product or material (downcycling), rather than being reused.
Despite the potential, we see that the degree of recycling and material extraction of construction and demolition waste also varies greatly per country. In the EU alone, this varies from less than 10% to more than 90%³.
Demolition is not only a problem when we look at our growing waste pile, but energy embedded in the materials is also lost (from the original production process, transport and manpower during the construction process, among other things). The new materials that will be used then generate new carbon emissions.
From Attaching to Detaching
The circular economy is now a well-known term for developers, builders, architects and material suppliers, but it is a principle that can be approached from various angles.
From a technical perspective, we often first look at the sustainability of materials when we talk about circular solutions in construction. Nowadays, for example, the use of building materials is increasingly being digitally recorded in a materials passport, such as Madaster.
But recording alone is not enough. It’s time to take a serious look at detaching materials.
Detachability or disassembly is an important precondition for making construction fully circular, because it makes it possible to reuse products and materials from a building and pass them on to subsequent cycles.
And there is good news: with the new collaboration between StoneCycling and Fassat Gevelsystemen (Facade Systems), demountable building has just become a lot easier.
What is a detachability index?
If a building is demolished or dismantled at the end of its lifespan, the building materials it contains can be ‘harvested’, which is also referred to as ‘urban mining‘. The products can then be given a new lease of life in a subsequent building. But they must of course be suitable for use in a new building.
This depends on the performance of the product itself after so many years of use and it also depends on how damage-free the product can be removed from the building: the detachability.
Technical detachability factors relate to design and determine the physical ability to disassemble objects. The connection between the object and the underlying object that has a load-bearing function determines the detachability index.
Three aspects are important for successful urban mining:
- the order of disassembly
- the type of connection of the element to its substrate
- the accessibility of this connection during disassembly
It is therefore important to clearly indicate in the design of a building which elements are easily detachable, how this should be done and where problems with detachability may arise.
And this does not only apply to the demolition of a building: also if maintenance or management has to take place (whereby one or more elements will be removed and/or replaced within the lifespan of the building), the various aspects of detachability are important.
“The detachability of a building is the extent to which products or elements can be dismantled at all scale levels, without compromising the function of the object or surrounding objects in order to protect the existing value.” – Losmaakbaarheid V2.0
Beyond Wall System: Detachable Wall System
StoneCycling has entered into a partnership with Fassat Gevelsystemen in the development of the Beyond Wall System. This innovative facade system is a lightweight product that is easy to process and with which facades can be built in a detachable manner.
The brick slips can be mechanically screwed to the wooden substructure using a modified PVC profile. This mechanical assembly also makes the brick slips easy to dismantle.
Reassembly is possible without the need for jointing.
Methodiek Losmaakbaarheid (Methodology Detachability)
In the past, there was no specific method to measure the degree of detachability in a building. That is why, in 2019, consultancy Alba Concepts, together with the Dutch Green Building Council (DGBC), the Netherlands Enterprise Agency (RVO in Dutch) and research and consultancy agency W/E, developed the “Meetmethodiek Losmaakbaarheid”, or the “Measurement Method for Detachability”.
This method creates a total impression of the detachability of a building or building design, expressed as a percentage.
The full explanation of this method can be found in the publication “Circular buildings – Meetmethodiek losmaakbaarheid“. This report provides a knowledge base for existing measurement methods such as GPR and BREEAM, which since 2020 include detachability as a credit in their certification.
It is worth mentioning that even without integration with existing measurement methods, the detachability index is suitable for use in residential and utility projects and at all building levels.
How is the Detachability Index calculated?
The method of Detachability looks at four factors of detachability of an element:
- connection type
- accessibility of the connection
- intersections of the element
- form containment of the element
Then a normalization factor is applied via the MPG* score of the element in question.
Elements with a higher MPG score have a greater impact on the detachability index at the project level. This is a motivation to make elements with a high environmental impact as demountable as possible.
The index is not only suitable for the building level, but also for making considerations at product level that promote reuse.
* MPG stands for “MilieuPrestatie Gebouwen” (“Environmental Performance Buildings”) and indicates the environmental impact of the materials used in a building.
Future-oriented building with detachability in construction
Detachability seems to be the key to accelerating the transition to a circular economy in construction. However, it does require a different way of designing: the principles of detachability will have to be incorporated integrally into the building process.
Architects and designers can increase the likelihood of a building being dismantled rather than demolished if they choose materials that will have high value in the future and prioritize detachability in their designs.
Detachability is at the basis of various other circular building principles, such as the high-quality reuse of building products, which means that the measurement method must always be applied in relation to other circular principles for maximum effect. The Beyond Wall System from Fassat and StoneCycling is an ideal combination of a detachable wall system and sustainable WasteBased and BioBased building materials.
The Methodology of Detachability has now been tested in practice at various buildings in the Netherlands on behalf of the Ministry of the Internal Affairs and the Transition Agenda for the Circular Construction Economy. The Beyond Wall System has recently won the Bouwbeurs Award in the category Circularity!
Would you like to know more about this collaboration or the application of the Beyond Wall System? Then please contact one of our experts.
- ¹ W/E rapport, Milieudatabase, 2013 [read online]
- ² Design Baddie: “How to Tell How Long an Interior Design Trend Will Last” [read online]
- ³ “Construction and demolition waste”, European Comission [read online]
- ⁴ “Circular Buildings – een meetmethodiek voor losmaakbaarheid V2.0”, DGBC, 2021 [read online]
- ⁵ Whitepaper “Circulariteit in de Praktijk Losmaakbaarheid”, DGBC, 2021 [read online]
- ⁶ “Handreiking Losmaakbaarheid”, PIANOo, Expertisecentrum Aanbesteden, 2019 [read online]