Lighting the way in architecture

Light is a foundational aspect of architectural design and practice - affecting how a building looks inside and out, and how that building influences its context and immediate environment.

Mistakes in daylight and sunlight analysis can lead to high-profile incidents like cars being melted by focused sunlight, as witnessed with 20 Fenchurch Street (The Walkie Talkie). But, more commonly, failures in light analysis will result in costly delays, time-consuming redesigns, litigation, and in the worst cases, demolition.

Light is a utility but it’s also an amenity for the people living in a building and those who live and work around it. While there are minimum standards governing light availability, our designs strive to maximise the benefits that daylight and sunlight provide and minimise their negative effects.

The emotional and psychological benefits of standing on a balcony, or stepping out into open space, and looking up into the sky should not be discounted - people’s wellbeing is closely tied to their daily access to daylight and sunlight.

Every site’s orientation and location are unique, therefore, daylight, sunlight, and shade from other buildings shape our projects in many different ways, from the overall massing of the structures to the choice of construction materials. Aside from the physical characteristics of our design that are informed by a light analysis, there are British Standards, building regulations and planning guidelines around the availability of daylight and sunlight that every design needs to meet.

British Standards determine adequate levels of natural light for a room and the methods for determining and assessing daylight provision, which influence internal layouts. The National Planning Policy Framework requires local planning authorities to ensure developments have a high standard of amenity, and local authorities each have their policies and guidance concerning daylight and sunlight that are tailored to the specific needs of their areas.

The Building Research Establishment Site Layout Planning for Daylight & Sunlight 2022 (BRE Guide), is perhaps the most definitive and exhaustive resource for planning and designing new developments with daylight and sunlight exposure in mind.

The BRE Guide outlines a set of standardised, functional tools, including the 25-degree rule and metrics like the Vertical Sky Component test (VSC) and Annual Probable Sunlight Hours test (APSH). These tools enable us to make detailed, repeatable and comparable analyses of buildings and their context.

Calculating various light levels and sightlines is now a complex and intricate task. We work extensively with Right of Light Consulting, a chartered surveying practice that specialises in the law, regulations, guidelines and effects of light, to ensure the compliance and success of our designs. Paul Hearmon, the firm’s senior right of light surveyor, is integral to our success in designing with light in mind, especially on larger-scale projects where matters become increasingly complex.

Hearmon explains: “There’s a significant degree of legal knowledge and precedent involved, especially when it comes to cases of a neighbour’s right of light and the kinds of mitigation or compensation that can be awarded. Without a detailed understanding of the legalities, and advice on the likely costs and consequences of breaching other parties’ rights of light can be catastrophic to a development.”

Engagement with issues of light is a must for any new development. When developing in urban areas, it’s particularly important to do so early because we’re often creating a new addition to an existing building, and there are established views and an expectation of daylight and sunlight among neighbouring property owners. Being able to identify likely planning objections means we can design around them, or mitigate them in some way.

This early involvement lets us create buildings and extensions as a cohesive whole that incorporate good light by design, and that are well-tuned to the needs and rights of the residents, neighbours, the local authority and all community stakeholders.