Daylight Factor Analysis
Walker Energy Analysis carries out daylight factor analysis for building projects across the UK, using IES Virtual Environment to assess how well daylight reaches occupied spaces under standard sky conditions. It’s the standard method for checking daylight adequacy at design stage, whether the driver is a BREEAM credit, a planning condition, or simply confirming a layout works before it’s built.
What We Assess
Average daylight factor measures how much daylight reaches a room’s working plane, expressed as a percentage of the light available outdoors at the same time, and is checked against the relevant threshold for the room’s use. Alongside this, we assess uniformity, whether daylight is distributed reasonably evenly across the room rather than concentrated near the window, since a good average figure can still mask a space that’s dim at the back and glary near the glazing.
We model using the building’s actual window design, room geometry and internal surface reflectance, and identify early where glazing area, room depth or reflectance changes would bring a space into compliance.
- Average daylight factor calculation, room by room
- Uniformity assessment across each space
- Reporting formatted for BREEAM, planning, or general design assurance
- Design-stage feedback where a space falls short of target
Why Work With Us
We’re a specialist energy consultancy. This is the core of what we do, not a sideline. Every assessment runs through IES VE as standard, and results come back in a format your team can use immediately.
FAQs
Q: What’s a typical daylight factor target?
A: It depends on the room’s use, and generally ranges from around 1.5% to 3%. We confirm the specific threshold for your project.
Q: Is this the same as climate based daylight modelling?
A: No, daylight factor uses a single, fixed sky condition. Climate based daylight modelling simulates a full year of real weather data, and is used for DfE school projects specifically.
Q: Can this support a BREEAM submission?
A: Yes, daylight factor analysis is the standard method behind BREEAM’s HEA01 daylighting credit.
Get Your Daylight Assessed Early
Talk to Walker Energy Analysis while glazing and layouts are still open to change.
Does your project need something else?