Hea 01 - Natural light

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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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 – relevant areas - KBCN0268

The aim of the View Out criteria is to allow occupants to refocus their eyes from close work. Relevant areas are spaces where close work in a fixed position is carried out for sustained periods of time. The view out criteria are therefore generally not applicable to occupied areas such as meeting rooms, or other spaces where such close work is not being carried out. Where rooms contain areas of different functions, only relevant areas should be assessed. In this case a notional line can be drawn on the plans and calculations made based on these relevant areas only. However, spaces such circulation routes or other transient spaces within a relevant area can only be excluded if the route or area is clearly defined by the building layout. If this is arbitrary or based solely on a proposed furniture layout, it cannot be excluded. Features of the building layout which may be considered as dictating a function area would include, for example, the position of doors or fixed furniture such as a reception desk or canteen servery.

11-Jun-2026 - Scheme applicability updated.
07-Oct-2022 - Additional paragraph added to clarify how function areas must be defined. 
21-Sep-2022 - General principle of 'relevant area' added, and applicability of KBCN extended to BIU V6 Commercial.

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