Thought Leadership

London’s Thermal Comfort Guidelines: Holistic Building Design

RWDI has spent several years collaborating with the City of London to develop pioneering guidelines aimed at better evaluating new building designs and the impact they may have on their surroundings. Our award-winning guidelines formalizing the methodology around pedestrian wind microclimate assessments were launched in August 2019, followed closely by the publication of guidelines for thermal comfort in December 2020.

London pedestrian street

These guidelines, believed to the first of their kind in the world, represent a significant move forward in urban planning for the same reasons that our wind studies were so important: major developments in dense urban centres mean a more thoughtful approach to design is needed, with more consideration for the surroundings and people in and around these new buildings and developments.

A building can affect its surroundings in many ways, from reflecting or limiting sunlight to altering wind patterns. When design teams are equipped with the right data from the beginning - allowing them to understand the microclimate of a building before it is built - such effects cannot only be mitigated, but also harnessed into sustainable, efficient opportunities for the area, its users, and the city as a whole.

The need for quality open-air public spaces has never been more important. Now, more than ever, people are heading outside in search of public spaces to rest and relax. Whether sitting, walking or exercising, they are choosing to do so outside. For some, the COVID pandemic prescribes that engaging in activities in an open-air environment is safer than doing so indoors. For the many Londoners living in flats lacking private outdoor space, there is simply nowhere else to go for a breath of fresh air.

The City of London requires a planning application for each tall building, which includes various environmental assessments. However, until now wind, sunlight and overshadowing have been considered separately, limiting a planner’s ability to evaluate the combined impacts of different environmental factors. Undertaking a thermal comfort assessment provides exceptional insight into the combination of unique factors that impact a person’s comfort, including temperature, humidity, wind, solar radiation, and how the space will be used.

Thermal comfort factors
Thermal comfort contributing factors
As per the wind guidelines, having a standardised thermal comfort approach is significant in that a consistent and robust assessment allows the city to easily review and compare neighbouring schemes. Cafes, parks, pedestrian routes – the continued enjoyment of all these open-air spaces is dependent upon thermal comfort. Equipped with this understanding early in the planning process, comfortable conditions in the neighbourhood can be achieved and compliance with local regulations assured.

As with the London wind guidelines, also authored by RWDI, the new thermal comfort guidelines are of significance in that they provide a map for other jurisdictions to adopt.

For further information, please contact:

Ender Ozkan or Ruth Shilston