…but flexibility on daylighting could build more housing

Increasing housing density by taking a more flexible approach to daylighting will help tackle the housing crisis, writes Gordon Ingram, senior partner at multi-disciplinary surveying and design consultancy GIA.

It’s clear that the housing shortage in London and the rest of the UK is an urgent priority. Some advocate a looser approach to the prospect of green belt development, or perhaps drastically relaxed planning laws.

But what other solutions are there? I firmly believe that a more flexible approach to daylight and sunlight guidance at the design and planning stages is the key to a significant increase in new housing. Tackle that, and we can unlock development in London and other city centres.  

Daylight and sunlight considerations are subject to well-meaning guidance, specifically the BRE’s, though the CIBSE and British Standards guidelines also comfortably reflect and endorse each other. 

Crucially, daylight guidelines are subject to interpretation, and as such they can be interpreted flexibly, especially within the context and location of a given site. However, at the planning stage many local authorities rigidly adhere to the guidelines as a “safety net” when determining density. While unintentional, this can significantly restrict development opportunity when critically focusing on a scheme’s amenity. 

What is needed is more flexible interpretation, in context with city centre requirements, where particular levels of daylight and sunlight may be acceptable. It’s also important to keep in mind that the BRE’s guidance was not developed with city centres in mind. 

To be clear, I’m not recommending a free-for-all on development – nobody wants or needs Hong Kong’s density in Chipping Norton. But it is important to consider that the blanket guidance on daylight for the whole of the UK does not address the specific context of our city centres. The situation in Soho, for example, is quite different to that of Sevenoaks. 

Since publication of the BRE’s guidance over 20 years ago, there have also been important technological advances in daylight analysis and simulation. Technology is important here, as it contributes to the adaptation of design solutions in context with a given location, using tools such as 3D simulations and parametric modelling. 

In practical terms, this daylight design advice may translate into refining and optimising the layouts, apertures, finishes, glazing and so on, thus avoiding compromising amenity. 

Applying the BRE’s guidance in a simplistic way probably means that decisions on density are being made without all of the facts, determining development potential on guidelines that do not reflect what might otherwise be acceptable solutions for the inner city. We’re unintentionally stifling acceptable development, for the sake of dotting the i’s and crossing the t’s.  

Simply put, a greater understanding of the guidelines and how they are commonly applied, coupled with changing hearts and minds so that a more flexible application can be adopted, will create more homes. 

Local authorities and planners, and to be honest developers, architects, lawyers and everyone involved in development, should all keep an open mind on increased density. This is a point we are actively tabling with the GLA and the DCLG.    

Finally, we are often asked about whether there should be separate BRE guidelines for city centres to address the fact that higher density areas need to be considered in a different fashion.

Currently, the BRE guidelines do state that city centres should be treated differently in some circumstances, and I suspect that they have deliberately avoided offering particular numerical criteria as each case will often need to be assessed on its own merits.

But simply having a wider appreciation within local authorities that less concern should be given to reductions in light and more to retained levels would bring about a different approach, and hopefully facilitate more development while intelligently seeking solutions to optimise amenity.