By Lewis Hewton
Outdoor thermal comfort is increasingly being recognised as a critical factor in successful urban developments. Unfortunately, outdoor comfort is not a widely understood building science, and high-level planning and design decisions are typically made in the absence of good quality, quantitative data.
To address this issue head on, Cundall have adapted the Adelaide City Council 3D city model to create an outdoor urban comfort model of the entire CBD and North Adelaide. This utilises large-scale computational fluid dynamics (CFD) analysis of wind, solar exposure and air temperature to provide a preliminary estimate of thermal comfort for any outdoor space within the CBD or North Adelaide.
Our city comfort tool can be used by architects, developers and planners from the earliest stages of design to quickly assess and refine the quality of outdoor spaces within the city.
What problem have we solved?
The use of CFD during the initial planning phases is rarely undertaken because it is a highly specialised, labour intensive, slow and expensive exercise. As a result, external comfort issues such as wind tunnelling effects are often not identified until it’s too late for cost effective mitigation measures to be integrated into design. Or worse, issues are not identified until complaints arise after project completion! Bolt-on late additions can spoil the aesthetic, the functionality and/or the project budget.
To provide cost effective early design stage advice Cundall have prepared an external thermal comfort model of the entire city. If it’s an existing building you’re interested in, we may have already done the work for you! If it’s a new development, we can quickly integrate the proposed design (from concept level and later) into the existing city model to assess precinct urban comfort and wind modelling of the proposed site. The result is a fast turnaround and quantitative external thermal comfort design advice being provided from the earliest stage of the project design.
Show me some
To illustrate the power of this tool we have modelled the conditions around our new Adelaide office, located at 33 King William Street (the purple building on the corner). Strong west and south west winds are particularly problematic for us. This would come as no surprise for anyone who has ever stood waiting to cross the Beehive corner lights at the end of the mall in winter. Fortunately, our building has an extensive awning to keep pedestrians out of the elements, but not everywhere in the precinct is so lucky. The image below is a visual representation of westerly wind conditions (red is fast, blue is slow – there’s no tornado outside).
The images below show a recent laneway redevelopment on King William Street and our wind visualisation of the location.
Why do urban comfort modelling?
Outdoor retail spaces are sources of income. Ever avoided an outdoor dining area because it’s baking in the hot summer sun? Left an activated laneway party early because it’s too cold and windy to enjoy your craft beer? Our city comfort model helps identify and visualise the root causes and solutions to these issues before they ever become a problem. The result is better planning and design, more usable outdoor spaces and longer customer dwell times. This in turn, leads to higher turnover for local tenants and business owners and a more vibrant city. Win, win.
How is urban comfort modelling different to wind modelling?
The difference is our city comfort model accounts for other factors contributing to comfort beyond just wind. This includes direct solar exposure, air temperatures and built form material temperatures (radiant effects). The modelling can be combined with historical climate data to predict and visualise urban comfort conditions at various times throughout the year.
We can also do wind analysis separately as sometimes this is all that is required.
How does this contribute towards the Adelaide City zero carbon ambitions?
The undesirable heat island effect of solar energy being trapped within the built environment is a well understood phenomenon and known to drive up energy consumption of buildings. City centres can be over 5°C warmer than surrounding suburbs. Our comfort model can be used to identify potential heat island hot spots and develop mitigation solutions, creating more comfortable spaces while indirectly reducing the air conditioning demands and energy consumption of buildings.
I’m developing in the Adelaide CBD or North Adelaide, is this for my project?
Yes. Most developments can benefit from more usable outdoor spaces – whether for retail revenue or for community activation. Until now, this type of design aid was cost prohibitive, but by making use of the Adelaide City 3D model, we’ve changed the game.
So if you are considering development in the Adelaide CBD or North Adelaide or you have a project on the go and would like to ensure the urban environment in and around your project is comfortable then please don’t hesitate to contact us as we may have already done the work for you!
Can this be rolled out in other cities?
Absolutely. Speak to us if you’re interested.