The built environment, together with civil and hydraulic engineering, is responsible for about 50% of raw material consumption in the Netherlands. In addition, the built environment uses about 40% of the total amount of energy and 30% of all the water. Besides new construction projects, much work needs to be done on existing buildings over the coming years, for instance to help create a zero-energy built environment. This enormous challenge offers the construction sector many opportunities to get started with circular principles.
For a circular built environment, the following two principles are especially relevant:
- circular design and assembly
- Circular material selection
Always validate your circular ambitions through market consultation as the main concerns may vary per project.
A building consists of many elements. Each element has particular function and its own life cycle. This is illustrated in the model below that shows the six ‘layers’ of a building. For example, a facade (skin) has a technical life cycle of 20-40 years, while the furnishing (space plan) has a life cycle of about 10 years.
In addition, there may be a temporary need for a particular function. ‘Temporary’ constructions, too, are considered to be circular, because they can be disassembled. Examples include the Temporary Courthouse in Amsterdam, or The Green House restaurant (Dutch) in Utrecht.
The various ‘layers’ of a building, that should be easy to disassemble based on functionality and life cycle. Source: Brand (1994), How Buildings Learn
There are several circular design strategies that can be applied in the design of a building. Depending on the type of building, the assignment and sometimes the 'layer’ of a building, you can opt for a particular strategy:
- Design for durability: Design for a long useful life, while ensuring that hardly any new material usage is required during the life cycle (example: robust materials)
- Design for standardization: Standardization – using standard dimensions – ensures that it is relatively simple to implement adjustments (example: standard dimensions for beams and columns)
- Design for repairability: The life cycle of a building can be extended by designing it in such a way that it is easy to repair (example: using easily accessible connections)
- Design for flexibility: Designing for flexibility makes it easy to change aspects of the building during the life cycle (example: ample space between columns and flexible partition walls)
- Design for disassembly: Designing for future disassembly entails that components can be disconnected easily (example: applying dry connections)
Material selection is a key aspect of circular building. There are several ‘circular material’ options:
- Reused products (such as reused doors, sanitary facilities and window frames)
- Reused materials or products with recycled content (such as concrete with reused concrete granules or partition walls of compressed waste wood)
- Materials or products that can be reused in the future (such as facade panels with snap connections or a building skeleton that can be disassembled)
- Biobased products (such as facade elements made from accoya wood or bamboo floors)
Select circular materials that are suited to the context of your project. Are you combining demolition and construction in your tender, and do they take place in succession? In that case, try to find ways to use demolition materials for the construction work. Of course, timing is of the essence if the materials need to be reused. Are you constructing a new building in a natural environment? In that case, your focus should be on biobased materials.
Do you want to know what has been used in your building? In that case you could request a materials passport. This passport specifies which materials and components have been used in the building, where these materials and components are located and how they can be disassembled. There are several systems available that enable you to generate a materials passport.
Platform CB’23 has initiated agreements on the type of building information that is recorded and the way it is recorded. The purpose of these agreements is to ensure a uniform method for creating passports for buildings. The agreements have been included in the guidelines (Dutch) on this topic.
Is demolition (or rather: disassembly) of a building inevitable? Determine how to achieve the highest reuse value of the generated materials. Depending on the state of the building, it may contain components that can be used elsewhere. If this is not possible you should aim for reuse of materials. It is important to bear in mind that ‘circular demolition’ (or rather disassembly) of a building takes more time and effort than traditional demolition. Careful disassembly into its components is more time-consuming than using a wrecking ball but ensures that the materials retain their residual value. This means that it is important to allow sufficient time for demolition and to start the tender procedure in a timely manner.
There is no single definition of ‘a circular building’. The circular buildings in the Netherlands that are often used as examples, each have a unique story to tell, focussing on different aspects of circularity. Eight different examples include:
- Park 2020, Hoofddorp: the design of this new business park is based on cradle-to-cradle principles. Healthy materials were used to increase productivity and reduce sick-leave.
- Garden City Overtoom, Amsterdam (Dutch): a project comprising demolition and new construction that reused more than 95% of the demolition materials in the new buildings.
- Alliander, Duiven (Dutch): a large-scale relocation in which the existing buildings were preserved, with high value retention of materials as a result. Future disassembly and reuse of materials have been key principles in this project.
- Municipal offices, Venlo: new municipal offices that have been designed based on Cradle-to-Cradle principles. The intention of the municipality of Venlo was to create a healthier city (a green facade to purify the air) and create a healthier working environment (lots of light, plants and fresh air).
- Temporary Courthouse, Amsterdam:a temporary building that can be disassembled. It will be used for five years during the demolition and construction of Amsterdam's courthouse. Once the new courthouse is completed, the temporary building will be disassembled and can be used elsewhere.
- Royal Haskoning DHV, Amsterdam (Dutch): a new office environment created in an existing building that formerly housed a car dealer. The building had been empty for some years and was likely to be demolished in the long term. A lot of reused materials have been used in the refurbishment of the offices.
- Circl, Amsterdam (Dutch): a restaurant pavilion constructed with as much reused material as possible. The building can be completely disassembled as well, driven by the desire of the owner (ABN AMRO) to experiment with circularity.
- The Green House, Utrecht (Dutch): a restaurant pavilion that was constructed as a temporary solution to be disassembled after 10 years. Many components have been reused or are purchased ‘as-a-service’.
- Explain to the market why your organisation wants a circular building. Determine on which aspect your focus should be, based on your needs and the scope of your tender: for example, reuse of existing material or future disassembly.
- Whenever possible, focus on the ability to disassemble the various elements of a building, both for new buildings and renovations.
- Get inspired by visiting one of the circular buildings. Most project managers will be happy to tell you their story and show you around!
The Dutch Rijn en IJssel Water Authority has built an installation for the production of Kaumera in Zutphen. Kaumera is a new biological raw material produced from sludge granules. The new building must support the circular aspect of the process: transforming waste into raw material.
Background information and downloads
The CB’23 platform is working on widely supported market agreements regarding the standardisation of circular construction principles. The results have been summarised in three sets of guidelines that can be downloaded from platformcb23.nl (Dutch).
These guidelines provide a definition of disassembly for construction and civil and hydraulic engineering, and shows how disassembly can be achieved.
The aim of this publication is to provide tools to generate a big healthy footprint for buildings. The focus is planning, financing and goal setting for development and renovation. Limited guidance is also provided for the construction, operations and decommissioning phases.
This report offers a potential set of indicators that enable you to provide insight in the circularity of a building. The indicators are based on BREEAM.
This Transition agenda details what needs to be done in the construction sector to move towards a circular construction economy by 2050.
This website offers various initiatives and the latest news regarding circular construction.