One of the great unintended consequences of having a network of clever individuals is getting to hear and see the wonderful array of DIY solutions to the warm weather!
Ice packs mounted to desk fans, basins filled with ice cold water to act as heat sinks, and timers set to close windows and blinds when the optimum internal/external temperature switch point occurs, there was certainly some creative solutions to a significant weather event.
But will these events continue to be significant, or will these simply become the norm? And do incoming occupiers within reason expect thermally comfortable spaces of houses built to modern standards and the latest regs for the warmer climate expected in years to come?
CIBSE TM59 is the go-to metric for residential thermal comfort, with the recently released Part O, the GLA and many others referring to this as the appropriate guidance. It is generally counted as a ‘pass’ if it achieves the relevant comfort criteria for the 2020 Design Summer Year 1 weather data relevant to the location. (e.g. median year with a reasonably warm summer). Future weather files are available and recommended to be undertaken but often only presented for ‘information only’.
If you are to look at my ‘amazing’ two-minute graph below, you can compare 19th July 2022 daily temperature profile in London (blue) against the peak day from recommended minimum weather data (orange). Cycling through the future weather data, the temperatures experienced were closer to a heat wave projected in 2050 (grey), correlating with the snapshot from BBC weather that many shared earlier in the week.
While it’s true that the primary comfort metric of TM59 is an adaptive one and would assume that our bodies could adjust to handle more regular warmer temperatures (to be honest I’m not how rapidly the human physiology could adapt to this!), the fixed metric of maintaining a maximum of 26°C in our bedrooms to enjoy a good night’s rest becomes far more difficult to achieve. This is before we potentially exacerbate the issue when we consider the additional heat gains that working from home brings.
Throwing cooling at the problem can’t be the solution, not only for our net zero ambitions but also that heat being extracted has to go somewhere, and that somewhere is the urban heat island, leading to a viscous cycle of temperature rises. Greater emphasis on future weather data, smart considered thinking on passive design and increased air movement is what is needed.
When the heat gets to my network of clever individuals, they deliver the innovative solutions needed. I look forward to hearing, seeing and presenting these solutions at my next design team meeting for residential buildings that will be standing in 2050.