Hea 01 - Natural light

Daylight – Shading devices - KBCN1815

If any of the assessed spaces are expected to contain moveable shading device (such as blinds), then a dynamic modelling of their use should be included in the calculation for options 2 and 3, consideration should be made to the shading guidance in EN 17037 or IES LM-83-23, respectively. Option 1 does not have to include dynamic modelling of moveable shading devices. This will be updated in the next re-issue of the new construction version 7 schemes.

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Glare control – Venetian blinds - KBCN1867

Venetian blinds must demonstrably meet the openness factor and transmittance value for blinds, where specified within a BREEAM manual. If the specification data for Venetian blinds is not available, evidence of the two points below can be provided instead: 1. The blind slats can be fully closed and overlap so there are no gaps between them. 2. The slat material clearly transmits no light, for example solid and opaque plastic, wood or metal. If the slat material is not solid and opaque, and is for example, perforated or made from woven fabric, the openness and transmittance values must be demonstrated in line with the criteria.

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Glare control – Modelling - KBCN1800

The ‘Glare control’ criteria do not require a specific methodology to be used to identify areas at risk of glare, and in most situations, a simple solar path analysis would be suitable. Alternatively, detailed hourly modelling methods, such as DGP and ASE, may be more appropriate. However, in either case, compliance cannot be assumed. Regardless of the methodology used, the modelling must be supported by robust reporting to demonstrate that each aspect of the criteria has been met.

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GN50 Natural light calculation methodology for Hea 01 in BREEAM V7 - KBCN1683

Latest version: v1.0, July 2026 Guidance Note 50 (GN50) describes the calculation methodologies that underpin the natural light issue (Hea 01) within BREEAM V7. Guidance is provided for methodologies relating to the daylight criteria and the evaluation of glare from daylight criteria. All the calculation methods outlined in the technical manual for these criteria are described in this guidance note. Download Guidance Note 50 View all Guidance Notes on BREEAM Projects (licensed assessors only)

15-Jul-2026 - Updated version released (v1.0)

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Studio Bedroom Daylighting Calculations - KBCN0733

Where studio rooms in multi-residential projects include multiple area types (e.g. A kitchen and lounge area), compliance can be achieved where either: 1. The entire studio room meets the more onerous requirements or 2. The room is nominally divided into the relevant spaces and the requirements are applied to each as appropriate.

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View out – communal lounges, living rooms and bedrooms - KBCN1828

The default criteria for these space types requires relevant positions to be within 5m of an opening. Where larger spaces are ≥ 50m2 NIA, the standard view out criteria for the relevant scheme is applied instead. The 5m rule is intended for small scale domestic spaces where proximity to a view out is beneficial. This KBCN recognises that for larger relevant spaces in Residential, Multi-Residential and Residential Institution asset types, a scalable approach in line with commercial buildings is more appropriate.

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View out – eye level - KBCN0581

BREEAM defines an adequate view out as being at seated eye level (1.2 – 1.3m) within the relevant building areas. However, where occupants will not have the option to be seated, for example in some industrial operational areas where the work being undertaken requires occupants to remain standing, the height of the view out can be changed accordingly to suit the eye level of occupants. All other view out requirements have to be met and clear justification provided for changing the height/level of the view out. In some relevant building areas, occupants may not be sitting down to undertake tasks. Allowing the view out height requirements to be changed accordingly ensures building occupants gain maximum benefit from the view out.   

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