Microclimate analysis allows for intuitive insights into perceived temperature

Jesper Staahl Jesper Staahl May 8, 2023

6 min read

Microclimate analysis - Spacemaker

Great outdoor spaces encourage public life, inviting people of all ages and backgrounds to meet, play and socialize. Perhaps they might stroll along a promenade, linger for coffee on a café terrace, or simply just hang out on seating steps and people-watch. Especially in an urban context, good outdoor public spaces are essential for improving people’s well-being.  

When designing these outdoor spaces, creating the right conditions that allow people to feel comfortable and safe is key. Microclimate plays a big role, since unpleasant conditions such as excessive heat or wind discourage people from spending time outdoors. At the same time, cities must now be equipped to face hotter temperatures that, in turn, worsen urban heat islands. It’s vital for architects and urban designers to be able to pinpoint problematic areas and address them at the earliest stage of designing so they can create the lively public spaces for people that they envisioned. This leads to implementing long-term solutions that are more effective and sustainable from day one and reduces the risk of having to implement high-cost fixes later in the process. 

Making informed decisions at the early stage 
Autodesk Forma’s microclimate analysis is designed to help users make more informed decisions about thermal comfort, at the early stage, when designing outdoor spaces. This analysis combines our sun, daylight, and wind analyses with local weather conditions to calculate the perceived temperature across your site. These insights will help you understand how to adapt your design to the local climate conditions for optimal comfort so you can achieve better outcomes.  

The perceived temperature is similar to when the weather forecast announces a temperature of 20℃, which feels like 15℃ because of factors such as wind or humidity. But our approach using the Universal Thermal Climate Index (UTCI) – considered to be both an accurate and respected indicator – takes this further by including a wide range of factors into consideration.  

The analysis allows users to explore the conditions of their site, and specific situations more intuitively. Historical weather data is used as a starting base to show typical conditions. In the Temperature section, users can configure specific times of day, air temperature and wind situation (speed, direction and incoming height). You can also now see the specific weather data used for your selected time and date, e.g., the percentage of humidity or cloud cover.

In the Comfort section, which indicates the fraction of time when the perceived temperature is expected to be within the comfortable range, users can now modify the comfort range for different times of the year according to the location. By moving the comfortable range selector from project settings to the right-side menu, we’ve also made it much more straightforward to quickly update this when assessing different times of the year. After all, most people have different ideas about what feels comfortable in summer and winter.

Considering microclimate is essential when designing future-proof urban spaces
As with everything we do at Forma, we listen closely to our users so we can better understand their needs and ways of working. For an update of the analysis, we worked especially closely with Danish consultancy Aaen Engineering. Their in-depth expertise about urban microclimates gave us valuable insights into the most important considerations and the value of microclimate analysis at the early phase of a project, especially when it comes to designing future-proof urban spaces in a sustainable manner. “It is essential to address the urban microclimate in the early design phases,” says Mathias Holm Sørensen, sustainability engineer at Aaen Engineering. “Both urban comfort and building performance are closely linked to the form, size, orientation and placement of building volumes, and it requires developers, urban planners and architects to consider the programming of both urban and building functions to accommodate the given microclimate in all the different spaces in the urban area.” 

Mathias Holm Sørensen is a sustainability engineer at Danish consultancy Aaen Engineering
Mathias Holm Sørensen is a sustainability engineer at Danish consultancy Aaen Engineering, which specializes in urban microclimates.

The consequences of not addressing microclimate conditions may potentially impact the quality of the spaces, and undoubtedly costs and timelines. “It becomes more difficult to use the microclimatic conditions to add quality to the urban spaces whether it’s to bring more afternoon sunlight near a café, or to invite a cooling breeze into the playground. If building volumes are placed without consideration for the microclimate, it is only possible to do minor adjustments later, for instance, by adding urban fixtures and trees to mitigate wind discomfort.” 

Helping the team with early insights 
In terms of workflow, Sørensen explains that Forma’s microclimate analysis helps the team get initial, indicative results about site conditions. By doing so, they’re able to see early on which scenarios have the most optimal conditions, and which ones have room for improvement. Later in the process, when more precise and advanced simulations are needed, they switch to specialist software which allows them to control all the details of e.g. the underlying wind simulations – using their expertise and experience to fine tune settings such as mesh refinement and turbulence models.  

For the early stage, Forma’s microclimate analysis speeds up the workflow for the team at Aaen Engineering and improves the decision-making process. “Once the geometry and analyses areas have been modelled in Forma, all the simulation steps are compressed into one click. This is a great improvement compared to our traditional workflows, which often required us to do many intermediary steps before getting an analysis result. Before, we could spend several days of work before we had any preliminary wind analysis results, but with Forma we can typically get a result within a day, and for several scenarios.” Sørensen also comments that different scenarios can be easily compared, enabling the team to provide factual arguments for design discussions. “Forma makes it possible to focus more on the interpretation and less on the simulation process, which makes it more usable for more people.”  
At the end of the day, it’s about creating spaces that people enjoy spending time in, and want to return to, and where they can thrive. How can we encourage more designers to consider microclimate at the early phase?  “It’s important to understand the role microclimate plays in the function of a space, and the various microclimatic parameters. But also how to use the findings to support architectural decisions from both the perspective of quality of life but also economic feasibility,” Sørensen says. “We plan our cities to provide the best possible conditions for people. The microclimate can be considered as way of stimulating our senses. The sounds of cars, machines or wind through the trees affect our hearing; the sun and wind affect our thermal reception; we smell and feel the air quality in our lungs. By understanding how important the stimulation of our senses is when doing the urban planning, we are more likely to create cities and spaces that feel inviting and comfortable for people, and know that it contributes to their health and well-being. By sheltering public space from cold wind and the hot sun, then we as designers, engineers and planners can extend the amount of time people spend outdoors, contributing to more urban life and healthier citizens.” 
For more information, please read the Help Centre article.  
We’d like to extend a big thanks again to Mathias Holm Sørensen for his valuable help with updating the analysis.  

Main image: Steven Lasry for Unsplash

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