New build or refurbishment?
Complexity lies behind the decision of whether to refurbish or rebuild. Analysis tools are needed, coupled with an understanding of each project to guide decision-making. Although the individual circumstances, lifetime and optimal outcome of each project are of course unique, trends can be identified.
The following diagram summarises whole life carbon – the interplay between operational and embodied carbon emissions – of 35 Sweco projects in the UK. Project categories range from light renovation to market-leading new builds. The assessment is in accordance with the UK Royal Institute of Chartered Surveyors (RICS) Whole Life Carbon Assessment methodology.
Data gathering is key. It is important to prioritise surveys at the earliest stage, such as structural surveys, architectural surveys, current energy performance surveys – what are typically called ‘condition surveys’. This information indicates what can be kept and what needs replacing. The quantification of existing materials, for example through Sweco’s C3 tool, is vital as it quantifies the materials and carbon that can be saved. It also facilitates the recycling and reuse of materials.
- Blue line. Light refurbishment with a lifetime of approximately 10 years. Although initial embodied carbon is low, operational energy emissions increase rapidly from Year 1 to Year 10. At Year 10 a complete overhaul is needed if the building lifetime is to be extended, and the embodied emissions subsequently increase.
- Yellow line. Major refurbishment with a lifetime of approximately 30 years. Although this analysis projects demolition at Year 30, if there was a comprehensive refurbishment, such as that carried out on the Blique hotel, the building should not need demolishing and the spike after Year 30 might decrease significantly. It is therefore possible for whole life carbon to perform better than a best-practice new build.
- Green line. Market-leading new build. New builds in the future are possible yet must achieve exceptional carbon performance. In this scenario, there is complete access to the most energy-efficient solutions. There may often be a higher initial embodied carbon, but with exceptional performance the whole life performance could work out to be a robust solution.
A key conclusion from this analysis is that the future of construction lies in high-quality refurbishment and market-leading new builds. Refurbishment could become the default assumption for any project looking to achieve strong whole life carbon performance, and only when you have exhausted the reasonable achievability of a refurbishment that meets both embodied and operational requirements should a new-build development be progressed. The opportunity may not always exist for market-leading new builds, so the role of refurbishment, such as the Blique hotel, is critical. To understand the optimal outcome for any given project, however, it is necessary to undertake analyses using tools like the Whole Life Cycle Assessment or Sweco’s C3 tool. By collating, analysing and contextualising such data, better decisions and outcomes can be achieved.
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Herein also lies an additional challenge for property owners, designers and data analysts: if you can not only build with ultra-low-carbon materials, but also design buildings that employ the circular principles of future flexibility, adaptability and deconstructability, and use tools that demonstrate this, why shouldn’t a new building last nearly 200 years and be continually adaptable over time?
An entire building could be transformed by circularity – the Blique Hotel case
The Blique Hotel is an example of how to extract and upcycle the resources contained in an existing building. Originally, it was an old warehouse and office building from the 19th century in central Stockholm, Sweden. Due to the low ceiling heights, demolition was likely.
However, because of its cultural and historical value, a competition was held to transform the building. Through the vision of a multi-disciplinary team from Sweco consisting of an architect, a cultural heritage specialist, a structural engineer and a material broker, the warehouse was transformed into a fashionable hotel providing new social benefits and a stronger identity for the neighborhood.
Reuse and circularity in focus at Blique by Nobis hotel, Stockholm. Client/developer: Kungsleden Fastigheter AB. Architects: Ewa Buhr-Berg and Karin Hurtig at Sweco. Photographer: Jeanette Hägglund.
Due to a lack of building documentation, a laser scan inventory was carried out to model it in 3D. The team then assessed the values of existing materials.
Using the digital model of the building and the tools, it was easy for us to calculate the total savings of embodied carbon in materials reused in the Blique Hotel case. In total, 3,600 tonnes of carbon emissions were saved.
In order to translate that into monetary values, we used the so-called ‘shadow cost’, which in Sweden means that every kilo of CO2e costs society at large 0.7 euros. Multiplying 3,600 tonnes by 0.7 EUR/kg, we concluded that the Blique Hotel had saved EUR 2.5 million. Moreover, the savings gained from reusing materials were worth EUR 8.6 million in new materials that did not have to be purchased. The savings for reducing waste totalled EUR 63/sqm.
By using circular methods when developing the hotel Blique by Nobis, total avoided costs 11.5 million €. Photographer: Jeanette Hägglund
So the take home message from this is that for every square metre of floor space we demolish, we can be effectively destroying a value of EUR 750.
What if we upcycled entire buildings in all of Europe?
What if we had an overview of buildings and available material assets across all of Europe? In that way, we could match demolition projects with construction and save a huge amount of carbon emissions by the increased reuse of building materials.
If we extrapolate the results of the Blique Hotel project, assuming they were applied to just 100 European buildings with the same size and characteristics, we could avoid total costs of more than EUR 1.1 billion. That result, which is based on Swedish carbon factors, includes embedded carbon savings, new material cost savings and the avoided costs of carbon emissions to society.
What if we developed circular disctricts in the city. The savings of carbon and cost would be significant. Total avoided costs 11.5 billion.
Applying the method of reuse to 1,000 similar buildings with a heavy core foundation and structure, such as Germany´s plattenbau, Sweden´s miljonprogram, or 1990´s commercial buildings, we could avoid costs of more than EUR 11.5 billion.
Imagine what you could do with that amount of money. Investments in clean tech and renewable energy. As an example, EUR 11.5 billion would cover the investment needed to construct the world’s largest offshore wind farm, Dogger Bank, in the North Sea.
From demolition to design for reuse
In order for digital tools to have the maximum impact and to actually realise the benefits they identify, it is crucial that key processes in projects and developments play their part in paving the way for greater circularity.
Gain more time to incorporate recovered materials into design
Municipalities and property owners play an important role as owners and developers of both land and buildings. By developing procurement routines for construction and demolition, as well as through their blueprints, installations and groundwork, they can have a profound impact on the transition towards circularity.
Sweco is currently working with the municipality of Malmö Stad on circular procurement and design instructions, linked to the EU Circular Builders project.
However, the gap in time between the planning and the actual demolition could disrupt the best laid plans. It often takes years to plan, design and construct a building, going through building permits and procuring contractors.
At the other end of the life cycle, demolition could be decided upon with very short notice, sometimes as little as two months before the actual demolition takes place. Even if the demolition itself was planned several years ago, property owners typically postpone publishing this information for as long as possible in order to avoid negative reactions to the change from local actors. The timely matchmaking of supply and demand of reused materials is an interesting challenge.
In order for digital tools to have the maximum impact and to realise the benefits they identify, it is crucial that key processes in projects and developments play their part in paving the way for greater circularity.
1 Exchange Square in London. By reusing foundations and 90% of the structure, the project saved 6,798m³ of concrete, saving 1,132 truck trips to site. Image: Secchi Smith.
Reclaim – how to predict what will be demolished
Reclaim (recovery and long-term asset inventory management) is a prototype tool developed by Sweco that aims to predict which buildings will be demolished in the future. The purpose is not simply to identify exactly when a particular building will be demolished and when, but it also enables us to visualise a future material bank within a wider area, with a degree of confidence that some of those materials will soon become available following demolition. It wins time to investigate the potential use of the materials in new projects.
The predictions from Reclaim are based on machine learning from historical government data, such as the year of construction, asset value, address or the history of permits for demolition, refurbishment, owner relations and function. The algorithm recognises patterns in the data for demolished buildings, returning suggestions for buildings that are likely to follow that pattern as a result.
Different cities have different patterns of demolition. For example, some cities were reconstructed after the war, whereas some cities remained intact. The tool provides a forecast setting out which demolitions to expect in the next 10 years.
1 Exchange Square. 90% of the existing structural frame was retained. The steel retained in the frame is equivalent to one-half of the Eiffel Tower. Client: PNBJ I / LaSalle Investment Mana- gement. Building Service & Sustainability: Sweco. Images: Secchi Smith.
Matchmaking for demolition
Matchmaking for demolition is another prototype tool from Sweco aimed at bridging the time gap between planning and demolition and better matching supply and demand for the reuse of materials in design and construction. This software tool scans the internet in Sweden for official municipality documents, targeting words like demolition, land allocation and exploitation/development.
The software generates a link to any municipality document mentioning these words and informs architects in advance of plans for demolition and construction in any specific location, enabling them to match this with their own design plans for construction within the same area.
Minimising risks with material passports
The purpose of material passports is to link and store circular data of buildings or infrastructure projects for the purpose of asset management, maintenance or reuse decisions. The passport contains data about objects, making it easier to estimate their circular value and to take strategic decisions. Sweco Netherlands developed Obsurv, a web-based management system that visualises materials in public spaces and enables the user to input details about materials so that it becomes a material passport.
The passport contains information including, for instance, which material or substance an object is made of, its qualities and estimated life cycle, geodata to make it easy to locate it and estimate its transportation costs, economic parameters, such as what it would cost to upcycle it, environmental parameters, such as embedded carbon already invested in the material, and cultural and aesthetic values.
Material passports address a significant barrier in the circular reuse of recovered materials, as documentation and information about origins are often crucial prerequisites for reuse. They reduce the perceived or actual risk associated with the unknowns of recovered materials and play a major role in reducing scepticism. It should be noted that human behaviour is also a major factor in circularity. Risk-averse attitudes are normal, so tools that address such concerns are critical.
Digital platforms as circular marketplaces for reuse
Even after identifying the value of existing buildings and finding direct and indirect ways of unlocking that value, much of this value cannot be converted without a marketplace for materials.
How to increase the reuse of building components?
The development of digital platforms for the reuse of building components, which is occurring simultaneously in several European countries, is one way to reduce building waste. The purpose here is to create a market for reuse and to better match need and supply. Digital platforms allow interested parties to share information, meeting the need for new circular services and creating a resource-efficient management of material resources. By digitising the material inventories and entering them into a digital marketplace, resources that can be reused, upcycled and rebuilt are made visible.
The CC Build platform is an open digital platform where all parties can publish and view available building materials. Sweco consultants are so-called ‘super users’, active on the platform several times a day, harvesting circular resources for their clients. There are also commercial platforms, for example Loopfront and Madaster.
With these applications, a property owner or municipality could easily create a database with the necessary information about the products and materials and classify them efficiently in order to know which products could be reused in a cost-efficient way, freeing up more time for creativity.
Vasakronan’s ambition with Kaj 16 is to minimise carbon footprint with very high ambitions for using reused materials. Examples of reuse: – 6400 m3 concrete from the old building are reused on site – 100% of all cable ladders are reused – 100% of all steel doors are reused – 100% of all acoustic ceilings in the offices are reused – 100% of all partition walls in glass are reused – 1100 m2 facade metal sheets from the old building are reused – 100% of all rebar is from recycled steel. Image: Vasakronan/TMRW/Dorte Mandrup
Recent developments include the combination of recycling services and digital platforms. Through the digital platform, objects for reuse as well as multi-disciplinary expertise in recycling at Sweco can easily be accessed.
Working with reused material in design requires more effort to find a circular option, as the fragmentation of information makes it inconvenient. In the Netherlands, a lot of groups have their own marketplace for reused materials, selling their own things. With the Sweco tool Revelop, the intention is to create a more efficient digital platform where all parties can see available materials and create a link to designer tools as well, for example, BIM (building information modeling).
Using the link between the digital marketplace and BIM design tools, the designer can connect data on what is available and add an artificial intelligence program to match demand with supply – a reverse design process. In the event of there being no available matching materials for parts of the construction, the designer can adapt the design to match the available supply – a reversed design process with a starting point in available materials.
Data ecosystems – avoiding silos
In order to better guide decision-making and extract circular value, different sources of data can be combined into an ecosystem of data, avoiding silos and enabling cross-functional and cross-border collaborations.
One example could be different resources linked to a certain value chain, while another example is the material flow within a city. It is crucial that both corporate and governmental structures enable this on a systemic level in order for a whole value chain to operate in a circular manner. We need to look at the interconnection of resources, in order for the whole ecosystem to function. It should be possible to excel at data and information management even with different organisational systems and structures. In many cases, it is a question of raising awareness that some tools exist.
Unfortunately, that is not always the case today, as we still have silos regarding how data is organised and how accessible it is. Sometimes, it is also hard to convince organisations to share their data, for example, to get a municipality to share climate data with a private company. Another challenge is multiple data formats. The discussion about standardised formats has been going on for several years, but the complexity, diversity and pace of change all make it difficult.
Digital twins – an ecosystem of data for a building
For property portfolios, one way to organise and create smart access to all necessary data for strategic decision making and reporting on buildings is to create a digital twin. For new buildings, 3D modeling is becoming more of an everyday practice for managing the complexity of information. It creates a good foundation for transitioning to a digital twin for the facility management phase and building operation. Existing buildings often lack adequate or up-to-date documentation.
A digital twin allows for the more resourceful use of a building’s assets from construction throughout its life, such as documenting its materials and properties, smarter operation, or creating the foundation for new business models that share resources between stakeholders.