Digital tool makes complex calculations easy to perform

Reference: City of Copenhagen

Photo above: Christian Brems

A newly developed digital tool for the City of Copenhagen’s Klimafacade+ project (Climate Facade+) allows complex background calculations to be transformed into simple visualisations of a facade project’s profitability with just a few clicks.

About the task

The City of Copenhagen aims to become the world’s first CO_₂-neutral capital. As part of achieving this goal, the municipality has developed the Klimafacade+ solution, which combines energy renovation with improved housing quality for older apartment buildings constructed in the 1950s and earlier.

Klimafacade+ consists of 5 elements (see figure) that are mounted
outside on the building’s existing wall. It is a big project and a big investment that those who pay must be sure is profitable – both financially and in terms of CO₂. It’s a large-scale project and a significant investment, so those financing it need to be confident that it is profitable—both economically and in terms of CO₂ reduction.

The City of Copenhagen therefore sought a calculator that could provide the necessary answers while being simple, clear, and easy to use, says Markus Claushøj Bindslev from the City of Copenhagen.

“The calculator is central to our ambition to promote Klimafacade+. Energy renovation is about payback—both economically and environmentally. So, although everyone wants building improvements, it often comes down to the financial aspect in the end. For the City of Copenhagen, reducing CO_₂ is also very important. Therefore, it is brilliant to have a calculator that provides good estimates of how much money and CO_₂ can be saved by implementing a Klimafacade+ on a particular building.”

KlimafacadeFigure

Figure: The physical elements that a climate facade consists of and that the calculator takes into account.

Reference: City of Copenhagen

Contract period: 2024

How we solved the task – methods and data

First, in collaboration with the City of Copenhagen, we determined which methods to use and the scope of our work.

The total economic calculations were to be performed as life cycle costs (LCC), allowing us to estimate the overall costs of a building, including operation, maintenance, replacements, and potential demolition over its entire lifespan.

The climate impact was to be calculated using a life cycle assessment (LCA), which provides an overview of the climate impact of implementing a Klimafacade+ project compared to maintaining the building as it is.

Figure: Example of a life cycle for a building.

After establishing the method, we began the work of finding the most accurate data for the calculations. Our sustainability team, which includes experts in LCA and LCC, was responsible for the calculations.

How we solved the task – user interface

As it was crucial to make the calculator easily accessible to the end-user, we involved a variety of employee competencies throughout the process.

Our digital team ensured from the outset that the calculations, background data, input, and output parameters were structured appropriately in the Excel file that forms the basis of the final digital tool.

During the process, a copywriter and a UX designer were also involved in the working group. They helped ensure that the calculator was developed with user needs in mind. With their input, the calculator was refined and adapted, making the final product understandable and user-friendly. This helped ensure that it can be used without prior knowledge of building energy renovation, insulation types, LCC, LCA, etc.

Throughout the process, a series of user tests were conducted with participants possessing different levels of knowledge on the subject, including building constructors and engineers. We used their feedback to adjust the tool, aiming to maximise user-friendliness.

Illustration – only in Danish: Screenshot from Klimafacade+

	Viegand Maagøe har hele vejen været utrolig skarpe på både det faglige og det projektmæssige. Vi var under hele projektet trygge ift. at få det produkt, vi gerne ville have. Samtidigt blev både tidsplanen og den økonomiske ramme overholdt, hvilket sammen med et rigtig godt slutprodukt er det vigtigste for os som udbyder.
	Markus Claushøj Bindslev Københavns Kommune

Results

The result is the calculator now available on the City of Copenhagen’s website for the Klimafacade+ project. The calculator will be fully integrated with the website to create an even better user experience.

With just a few inputs about the existing building and by selecting the composition of the desired Klimafacade, users receive an estimate of how many years it will take for the facade to pay for itself in terms of economic costs and CO_₂ savings.

In this way, the calculator can clearly and simply show the perspectives for economy and CO_₂ emissions of Klimafacade+ on the specific building. Additionally, users can experiment with different material choices, reuse of materials, insulation quantities, and timeframes to get an idea of the best model for their property.

The tool’s primary target audience is advisors and property owners, who are expected to have a relatively high level of insight into this type of energy renovation. However, the calculator is also designed to be usable and understandable for residents in, for example, cooperative and owner associations.

About the technical/digital solution

The calculation tool is built in Excel with a sharp focus on user-friendliness. This is ensured through easily readable text, sharp contrast colours, and explanatory text for the input fields. To keep it manageable, there are only three tabs the user needs to navigate: Introduction, Calculator, and Method.

Behind the calculations in the calculator tab are various data tables with material data, energy forecasts, and calculation of time series, etc., on tabs hidden from the regular user.

Once all the information is entered, two graphs are generated for climate impact and economy, showing the estimated payback time (in DKK and CO_₂) of the selected Klimafacade compared to the existing one. The results can also be viewed in table form, where the impacts/costs are itemised for the various activities in the process (materials, construction process, energy savings, maintenance, procurement, one-off costs, replacement, supply, etc.).

Amro Hajir

Senior Project Manager and Team Leader, MSc in Climate Change

Mobil: +45 60 29 78 10

Contact

aha@viegandmaagoe.dk