As heatwaves surge in the United Kingdom, millions struggle to stay cool. Chaos’ Roderick Bates looks at how architects can use 3D visualisation technology to design the buildings of the future by borrowing from the past
On the heels of some of Britain’s hottest summers ever, many wonder how the UK will cope with the increasing number and severity of heatwaves.
The recent rising temperatures are more than just an annoyance, with sensitive population groups, such as the elderly, at particular risk. According to government data, heatwaves have killed more than 12,000 British people since 2017.
Historically, British homes have been built to trap heat, insulating as much as possible to keep people warm during cold, wet winters. However, with increasingly warmer weather, the same feature that historically helped reduce heating energy has become a liability during the hot summer months.
Minimising heating energy is still important, but cooling structures in a cost-effective manner is becoming increasingly relevant – and for those in poor health, an imperative. To find a solution, architects need to go back to the drawing board and apply design strategies from regions with a long history of hot climate management.
Modernising the design process with 3D visualisation
Given the long history and deep culture of housing design in the UK, a complete overhaul of the design of homes is no easy feat and likely unfeasible. It is a game of trial and error.
Mistakes can be costly and not altogether visually pleasing. 3D visualisation technology can help by allowing architects to experiment with designs before their implementation, evaluating not only their aesthetics but also their environmental performance.
By providing tools to visualise potential designs before they are executed, 3D rendering helps architects, designers and the eventual occupant better understand and evaluate design options.
Stakeholders can make necessary changes to optimise for comfort, energy performance and aesthetics. Through the use of visualisation to facilitate design making, the design process isn’t just improved, it’s accelerated by minimising delays from protracted decision making.
It also allows for design missteps to be “seen” digitally and corrected before they are physically made, where the cost of correcting them is exponentially higher. In practice, this means producing a visual representation of how cooling methods can be implemented into new designs and existing structures, running rapid energy models using appropriate comfort set points for cooling and heating. Eventual occupants can then understand easily how the finished product would look and function.
What about air conditioning?
Currently, less than 5% of British homes have air conditioning units. Adding these components to new designs or existent buildings sounds like the logical solution, but it’s not so simple.
More than 10m buildings in the UK were built over 80 years ago. They lack the basic infrastructure required to easily install air conditioning units.
The extensive use of brick and the lack of air cavities in existing structures make it particularly difficult to install air conditioning units. It is almost impossible to retrofit ductwork, especially in terraced houses where the party walls eliminate the easy placement of the condenser units required by HVAC systems. Mapping out the feasibility of an installation, by virtually locating equipment on site in a rendering, is essential.
While air conditioning is an option, the cost and difficulty of installation, not to mention the long-term cost of maintenance, make it a strategy best deployed as a last resort, or at the very least on a building where passive cooling strategies are already exhausted.
Additionally, air conditioning isn’t without environmental consequences, accounting for nearly 4% of all greenhouse gas emissions and 10% of all electricity consumption worldwide.
The best strategy is to use air conditioning as the final comfort measure, after more sustainable and cost-effective traditional strategies for passive cooling are deployed.
Passive cooling
People have used passive cooling methods to regulate temperature since ancient times – upper-class Romans had impluviums, shallow pools that cool a home as water evaporates. Even Neanderthals took advantage of the thermal mass of caves, which provided a cool refuge from extreme temperatures.
Sceptics may wonder what contemporary passive cooling methods look like, considering that most people wouldn’t dream of living in a cave, and hardly have room for an indoor cooling pool.
Passive cooling can include minimising solar gains, with strategies as simple as adding external blinds, painting roofs white and walls a lighter shade to reflect the sun’s radiation.
Another option would be to add upper-storey exhaust fans to evacuate hot air and operable windows to bring in cooler air at night.
More invasive methods include installing preventative techniques in a building’s structure to prevent internal or external heat gains. These passive methods lower interior temperatures, reducing HVAC usage and, in turn, lowering electricity consumption and bills.
This isn’t just speculation. One study found that passive cooling methods result in an average temperature drop of 2.2C, a reduced cooling load of 31% and a 29% saving in energy consumption.
In contrast to the likes of air conditioning, passive methods even work during power outages, which is particularly relevant for areas with unreliable power grids. With warnings from the Net Zero Watch Group that the ageing UK power grid has limited capacity, this is increasingly concerning.
Given the above, for new builds, there’s more reason than ever to design with passive cooling in mind. And there’s still plenty of opportunity to redesign existing structures with passive features, even on limited budgets.
3D visualisations can illustrate design moves to mitigate solar gains and maximise passive cooling, such as deploying external shading devices, repositioning windows and doors to enable cross ventilation and changing the exterior paint colour.
They can also model design elements like ventilated gaps between the ceiling and roof, allowing stratified hot air to escape, helping assess feasibility and aesthetic impact before construction.
The future of climate resilient homes
Regardless of style, budget, or location, there are a variety of techniques that can be implemented to new buildings or existing structures to help the UK cope with the rising temperatures.
While changing anything with as deep of a tradition as homes in the UK is no small task, 3D rendering software can help architects and stakeholders test and visualise how active and passive cooling can be integrated into both new and existing spaces.
At Chaos, we are dedicated to empowering the sustainable designs of the future, even when it means borrowing from the past.
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