CO2mpare is an interactive database launched by TDUK members Ramboll, that reveals the typical carbon emissions of their building projects. It covers multiple countries, typologies and project types. It provides a fascinating insight into their progress in decarbonising their projects.
The database currently holds 203 project assessments across the UK, Europe, Nordic countries and Singapore.
Buildings can be viewed in CO2mpare in a number of ways, with one filter allowing you to investigate by ‘concept design’, ‘technical design’ and ‘post-construction stage’ (as-built). It is browsable across 11 common building typologies – such as residential, educational, hospital and industrial. You can search by ‘new build’ or ‘renovation’.
A screenshot showing the database in use
And you can look at all the projects’ carbon emissions by 12 different combinations of ‘scope’ – meaning you can choose to view by ‘whole life carbon’, ‘operational’, ‘total building’ (A1-A3 or A1-A5), ‘superstructure (A1-A3)’ and other options. It is a fascinating and fun tool to use. Browsing the different options provides a real insight into Ramboll’s work and the carbon associated with it.
Ramboll’s benchmarking mission
“CO2mpare is one aspect of a broader project, which is our internal carbon benchmarking database,” explains Paul Astle, Decarbonisation Lead at Ramboll.
“Its aim has always been to collect carbon assessment data from around Ramboll’s business to allow useful analysis: to make sensible targets going forwards, to identify best practice and to track our own performance as a business, relative to our decarbonisation goals.”
That process began some four years ago, and has taken place over a period in which information about carbon assessments – and their regulation – has been changing rapidly.
“It can feel as if there’s new guidance coming out every week,” Paul admits. “We’ve been trying to build this system and keep up with the various changes at the same time.”
Interior of Brent Cross Pavilion, for which Ramboll were structural timber engineer
The challenges of comparing carbon across countries
He points to the example of Denmark, where there is now a carbon assessment requirement and an embodied carbon limit value for various different building types.
Detail from the Tree House project at Elephant Park, for which Ramboll provided timber engineering services
“We’re trying to develop a system in which we could meaningfully compare data from an overseas project with a UK project. So we’re trying to make the user interface as easy as possible for people to provide us with their carbon assessment data: our system must be capable of receiving carbon assessments that use many different tools and methodologies. In Denmark, LCAbyg is the most commonly used assessment tool. We also make carbon assessments using One Click LCA, and using our own in-house tools.”
“Going forward, we’ll be including information on the materials used, and the masses of those materials as well. It will probably begin with concrete, steel, timber and masonry, largely because they are typically the most common materials.”
There are several challenges in compiling the data for CO2mpare. One is that the scopes of different carbon assessment methodologies vary quite significantly.
“Although everyone uses the same fundamental definition of lifecycle module, they don’t necessarily have the same minimum requirements for them. They also, in some cases, conflate different modules together,” Paul explains.
“In Sweden, in some cases, they have reported an A1-A5 single figure, which means that we can’t compare it to an A1-A3 figure. In Denmark, they conflate the benefits of sequestered carbon of timber as part of a whole life assessment, but these need to be reported separately when only comparing an A1-A3 figure.”
And while everyone may be pretty clear on what the life-cycle modules are, how you break them down by the building element is not clear: what counts as substructure, superstructure, building envelope, for example.
“Our categorization is more or less aligned with RICS, but there’s a few subtle differences. We need to be very clear on what we include in our different components, so that people can understand what that means.”
The increasing significance of renovation
It’s informative to click on ‘renovation’, rather than ‘newbuild’, and see how much of Ramboll’s work lies in that area – and which countries its happening in.
“Ramboll have created many parts of the business that focus on renovation or existing buildings, and it’s an area that we’re actively pursuing now: if the industry is going to achieve its decarbonization goals, it can’t get there just by using lower carbon materials. We have to look at reuse of existing structures and materials.”
“As a business, we are trying to upskill in this area: how do you treat existing buildings and how do you assess them? How do you give them a new lease of life? We are developing some active training on this front, to understand how we can look at existing assets and reimagine them in some way.”
The F51 Centre in Folkestone is another Ramboll project: CLT was used for the indoor skatepark
Comparing different typologies
It’s tempting, when browsing CO2mpare, to attempt to try to spot patterns and trends over which building types tend to be lower carbon, and it’s important to remember that there are many qualifying factors that affect all of these projects, spread out globally.
“As an industry, we’d probably need tens of 1000s of carbon assessments before we could really start to see any clear trends,” Paul cautions. “Take ‘residential’ as a sector: that could refer to a house, which can be incredibly low, but it could also be a 20-storey tower, which can of course be quite high.”
“In Nordic countries we tend to do a lot of lower-rise buildings, which inevitably have more options for more sustainable solutions generally – your whole structure is just a bit lighter. You might be able to avoid some of the systems necessary for a taller building; you might have a less extensive basement.”
“As an industry, it’s still early days in correctly understanding and interpreting LCA data. But we really wanted to get CO2mpare out there to start conversations, to show the kind of numbers that we’re getting at the moment. It does display some trends – renovation being an obvious one – but more data is needed.”
For its own projects, Ramboll is targeting a reduction of embodied carbon of 50% by 2030 against a 2021 baseline. Reducing the carbon of the building structures they design is their biggest focus, Paul explains, because upfront carbon is almost always the biggest carbon emissions source. To achieve their targets, they need to be assessing and tracking their progress.
“We want to build up some carbon literacy in the industry, and among our clients. It’s a good start to get insight into our projects and understand the numbers.”
