LINK IO of LINK Arkitektur integrates microclimate studies in-house.

The Project – Microclimate Analysis of a New Housing Project

The project in question is a new master plan and housing project in Dolvik, in the municipality of Bergen, close to a fjord. The location close to a fjord on the west coast of Norway gives rise to a need for detailed microclimate analysis. Originally designed in 2018, the slightly delayed project took on significant sustainability demands when restarted that were not on the original brief. A net-zero commitment on some of the housing plots was also added, leading LINK IO to propose wind studies due to the unique nature of the fjord. At the time of writing, the project is currently going through the planning approval process. The location can be seen on the map images below.

To meet strict sustainability and net-zero commitments, the housing units have a high proportion of their roofs covered in solar photovoltaic (PV) panels. The wind simulations using SimScale were needed to evaluate the windy conditions on site for pedestrian wind comfort and safety, as well as for roof terraces and safety limits for roof-mounted solar PV panels.

Mathias Sønderskov Schaltz, Computational Design Lead at LINK IO, has been leading the environmental studies. Their purpose in using microclimate analyses is to optimize design solutions and ensure compliance with regulatory requirements for indoor and outdoor climate and the general well-being of residents.

Wind Simulation at LINK IO

The wider practice has experience using a variety of CAD tools including Rhino, Sketchup, Revit, and ArchiCAD. In this case, they were using Rhino geometry to import into SimScale seamlessly. The workflow from Rhino to SimScale is simple and intuitive, and one of the arguments for choosing SimScale. The LINK IO team found it easy to import terrain and topographical features, something that is critical in Scandinavia. The lattice Boltzmann method (LBM) solver in SimScale handles terrain in 3D models well, and bringing in GIS data via ArchiCAD is relatively simple. Another advantage was that SimScale has an integrated climate database to read from and can also import/customize bespoke weather data files. Some of the design questions LINK IO were looking to answer with SimScale included:

• Is the site comfortable due to the natural topography and master plan layout?
• Might any wind mitigation measures be required, for example, trees and windscreens?
• Are the roof terraces and walking areas comfortable for pedestrians?
• Is the load on roof-mounted solar PV panels too high?

Joel Lopez, Computational Design Architect at LINK IO, is an urban designer with a focus on creating comfortable cities. He has conducted wind simulations on more than 20 projects through SimScale over the last year. In this project, he modeled much of the local terrain in detail, including several tree species. From initial simulations, the team found the site to be naturally comfortable due to the local wind and sheltered area the housing project was in. With quick alterations to the CAD model in SimScale, they are also able to iterate the design and compare wind comfort scenarios. After the simulations, the team provides documentation and feedback to improve the design proposal. The team strives to make wind analyses more accessible to architects and more meaningful for the final design.

Outdoor Comfort in Extreme Environments & Challenging Terrain

Outdoor comfort simulations require enhanced analysis, especially in the Scandinavian context, where there is often challenging terrain and extreme weather changes that are not captured by statistically average climate data files. Link IO has a simple process to work with Outdoor Comfort:

• Step 0: The Scandinavian context – reduce wind impact on comfort in an already cold climate by protecting from cold winds year around.
  • Site selection: use a naturally sheltered location if possible
  • Orient streets perpendicular to the prevailing wind direction
  • Use winding or angled streets
  • Create uniform building heights
  • Use windbreaks, either natural, like trees/vegetation, or artificial such as street furniture, wind canopies, and windscreens. 
• Step 1: Know your weather data at the actual site (not a weather station 20 miles away)
  • General conditions including temperature, precipitation
  • Wind data: Wind rose, directions, frequency, seasonality
  • Outdoor Comfort variables
  • Understand how terrain such as fjords impacts wind
  • Compare sources of weather data from different databases to be sure
  • Start with some simple spreadsheet analysis 
• Step 2: Build a climate strategy
  • In terms of wind:
    • Protect from the wind by blocking, diverting, or diffusing?
    • What features need to be considered, including topography, forests,
      big surrounding constructions, and regional currents?
    • Which wind directions are we going to protect from?
  • In terms of UTCI:
    • How big is wind in the overall UTCI equation for the location? 
    • What are the number of clear days we’re optimizing for?
    • How do we incorporate predicted higher average temperatures and lower average wind speeds from the IPCC climate projections? 
• Step 3: Test and iterate
  • Prepare geometry and use SimScale for the transient wind analysis part of the UTCI calculations – via a Python script that calls the SimScale API
  • Import wind results into wider UTCI calculation via Rhino/Grasshopper
  • Iterate geometric designs and layouts 
  • Automate the above process as much as possible 

Case Study of Viby Centret, Aarhus

An urban transformation project in Aarhus, Denmark is adding housing and large-scale outdoor spaces to already existing commercial buildings. Link IO evaluated the existing development to begin with by performing wind speed and climate analysis of the site. This created a first design iteration shown below, where spaces of high winds have been observed. Through various design elements, including vegetation, trees, and windscreens, the third iteration (also shown below) shows much-improved wind comfort criteria. The wind speed results have been input into a custom UTCI workflow developed by Link IO to further calculate the UTCI outdoor thermal comfort results, as shown in the series of images below. The final result is a tried and tested workflow that allows Link IO to iterate and evaluate designs with outputs calibrated to those that give the maximum design insight, including wind speeds, wind comfort, and outdoor thermal comfort. Using the SimScale API, the designers can easily automate this process and use advanced generative design technologies to quickly analyze changes and enhancements to the development.

Next Steps

LINK IO is looking to use the SimScale API to automate wind studies and corresponding reporting/documentation. The need for mandatory wind studies is increasing in much of Scandinavia, driven by compliance requirements by local municipalities and sustainability systems, including BREEAM. Previously, LINK IO might have commissioned a wind analysis outside the organization. With SimScale, the team now has inhouse-access to fast and accurate wind simulations from the very earliest design stages. LINK IO can now integrate microclimate studies in-house on all projects, a growing demand from their clients. Calculating the Universal Thermal Comfort Index (UTCI) is also high on their agenda, using SimScale’s readily available Ladybug and Grasshopper scripts, as well as exploring more of the collaboration features in SimScale. The outdoor example above has been a successful experiment where Link IO has created a bespoke tech stack for their design teams by connecting multiple software tools such as SimScale and adding in custom scripts to automate the design process.