Meeting the new expectations for daylight in development

The Healthy Homes Standard links daylight more explicitly to wider objectives around comfort, well-being and quality of life. At the same time, it forms part of the expectations surrounding homes delivered through Homes England funding programmes.

This means daylight performance is no longer just a design quality issue, but part of the wider conversation about whether schemes meet the standards expected of publicly supported housing.

“The shift required is not particularly technical – it is largely about asking the right questions sooner”

Despite this policy shift, the way many schemes are designed has not yet caught up. Across the sector, daylight modelling is still commonly commissioned towards the end of RIBA Stage 3, sometimes only weeks before a planning submission.

By that stage, the core elements of the scheme are largely fixed. Apartment layouts have been refined, structural grids established, façade strategies agreed and the development appraisal aligned with a specific unit mix. If daylight testing then identifies problems, resolving them can be difficult.

Window sizes may need to increase. Balcony projections might have to be reduced. Deep-plan apartments can struggle to achieve acceptable daylight distribution. Clusters of north-facing single-aspect homes may suddenly become problematic.

Occasionally, the only realistic solution is reducing unit numbers. None of these changes are welcome when a project is approaching planning. They can introduce redesign costs, delay programmes and – worst case scenario – create uncertainty around the assumptions underpinning the scheme.

For organisations delivering homes through the Social and Affordable Housing Programme, avoiding uncertainty is particularly important.

Funding agreements rely on schemes progressing with a reasonable degree of confidence. When significant design issues emerge late in the process, that confidence can quickly erode. The simplest way to reduce this risk is to move daylight analysis earlier in the design timeline.

Early modelling does not require a fully resolved scheme; even indicative layouts can reveal whether a proposed massing strategy, building depth or orientation is likely to create problems later. Identifying those issues at concept stage allows the design team to respond while the scheme is still flexible.

Core locations can be adjusted, building depths refined or unit mixes rebalanced without major disruption. Attempting the same changes later is far more difficult.

The shift required is not particularly technical – it is largely about asking the right questions sooner. At concept design stage, development teams should already be interrogating some key fundamentals.

How many homes are single aspect and which direction do they face? Are living spaces positioned on the elevations most likely to receive good daylight? Does the building massing allow enough sky visibility to lower floors? And are density ambitions compatible with the daylight performance expected under the Healthy Homes Standard?

“Testing daylight performance during early capacity studies allows development teams to understand constraints before they become embedded in the scheme”

These questions become especially important on constrained urban sites, where surrounding buildings and tight street sections can quickly limit daylight availability. Testing daylight performance during early capacity studies allows development teams to understand those constraints before they become embedded in the scheme.

The Healthy Homes Standard is not intended to slow delivery. Its purpose is to ensure new homes support residents’ health and well-being by providing access to daylight, sunlight and views. But it does send a clear signal about the direction of housing policy.

Daylight is no longer just a technical report produced at the end of the design process. It is part of the wider framework through which the quality – and increasingly the deliverability – of housing schemes is judged.

Those that recognise this early and design for daylight from the outset will protect programme certainty, safeguard funding confidence and avoid the kind of late-stage redesign that no development team wants to face. In today’s housing delivery environment, the safest schemes are the ones where daylight has been designed in from the very beginning.

Mike Scanlan, director, Proximity