Daylighting Calculations

Good levels of daylighting are crucial to occupant comfort in new buildings.

Daylighting calculations can help designers to mitigate against the risk of poor natural light and also provide credits against Code for Sustainable Homes and BREEAM assessments.

Why Do I Need Daylighting Calculations?

Daylighting analysis is commonly required in 4 instances:

Daylighting Calculations

Daylighting is not a mandatory issue in Code Assessments, but most of our clients find it a relatively inexpensive and effective means of gaining extra credits.

BREEAM also offers credits in it’s Health & Wellbeing / Visual Comfort category.

In both instances the assessor will need to see compliant daylighting calculations. For example, Code Assessments these will need to demonstrate that daylighting factors achieve 1% in bedrooms, 1.5% for living rooms, and 2% for kitchens.

Working plane calculations need to show that 80% of the working plane in a room receives direct light from the sky.

What Makes a Compliant Daylighting Calculation?

Several key standards exist to provide guidance:

  • BS 8206-2:2008 Lighting for Building – Part 2 Code of Practice for Daylighting
  • CIBSE Lighting Guide LG10:1999 – Daylighting & Window Design
  • Communities & Local Government Code for Sustainable Homes Technical Guide Nov 2010

Daylighting CalculationsDaylighting Calculations may be performed manually using the above standards, guidance and formulae.

They may also be carried out using Dynamic Simulation Modelling (DSM) software packages such as those provided by IES and TAS. These allow for much more sophisticated 3D modelling and analysis.

Build Energy can provide daylighting analysis across a multitude of buildings, from one-off self builds to very large and complex mixed use schemes, using DSM technology. We can create bespoke reports tailored to your requirements, and find solutions to any issues.

Want to discuss Daylighting Calculations?

Just give us a call on 01202 280062 or send us your enquiry - we’ll get straight back to you.


Everyone at Build Energy was extremely helpful from the start - I am a householder, not a professional builder and they answered my questions and queries with patience and knowledge........the service was always quick, efficient and professional and I would definitely use Build Energy again

Hannah Griffiths – Dunlace Rd