02 - Health and wellbeing - BREEAM Knowledge Base

Acceptable deviations – ISO 7730:2005 category B - KBCN1714

Acceptable deviations from category II thermal modelling criteria can be made in accordance with CEN 16798-2:2019 Anne E, only when the thermal comfort assessment uses CEN 16798 to demonstrate compliance. Where this is the case, up to a 6% deviation based on yearly occupied hours can be accepted when demonstrating compliance. ^{Note: this KBCN no longer allows the deviations to be used for ISO 7730:2005. However, for assessments where the assessor has advised the project team based on the original KBCN, prior to this update, this will be honoured if you provide evidence of this in your assessment.} ^{KBCN wording 16 Jan 2025 - 10 Jul 2025:} ^{~ Acceptable deviations from the ISO 7730:2005 category B criteria thermal modelling criteria can be made in accordance with CEN 16798-2:2019 Annex E. Up to a 6 % deviation based on yearly occupied hours can be accepted when demonstrating compliance ~}

10 Jul 2025 - KBCN updated following further review of relevant standards

Adaptability for a projected climate change scenario – Winter conditions - KBCN1715

Where future climate change scenario projections in winter indicates a higher temperature and, therefore, more thermally comfortable climate compared to the current winter temperatures, it can be assumed that the winter conditions within the climate change scenario are met based on the thermal modelling of current winter conditions. Justification must be provided for each project confirming that the future winter conditions will be met with the current heating system. In a warming climate the heating system needs to be sized for the beginning of its lifespan, whereas the cooling systems need to be sized for the end of their life span (Ref: CIBSE TM55: 2014)

Assessing thermal comfort – Residential buildings - KBCN1408

CIBSE TM59 can be used to demonstrate compliance with the thermal comfort requirements for residential buildings, instead of ISO 7730:2005. This is to recognise the most up to date methodology relating to the assessment of homes.

26 Jan 2025 - Updated to apply to multi-residential buildings (long-term stay) and scheme applicability extended to account for this.

BREEAM Daylighting – Alternative methods - KBCN1821

Within the BREEAM daylight criteria, there are two detailed calculation options of either using the average daylight factor method or average and minimum daylight illuminance method. The use of the standards within the table below, can now be used as approved alternative calculation methods. The performance requirement must be met in line with either the standard or exemplary criteria as set out in the table below:

To use either the EN 17037 or IES-LM-83-23 option, the methodology within Guidance Note 50 must be followed. In addition, the minimum percentage area to comply, dependant on the building type and space type, must be met in accordance with the criteria within the relevant BREEAM issue. To calculate the percentage of assessed area that complies, follow KBCN0471 or KBCN1081. Example: A school using the International New Construction V6 scheme, has used the IES-LM-83-23 sDA method to calculate the daylight performance. The nominal level is achieved in all occupied spaces. The minimum area to comply is set at 80% as per table 10 and 12. As 100% of occupied spaces meet the nominal level, 2 credits can be met.

Emissions from construction products – Re-used and reclaimed products - KBCN1869

The Emissions from construction products criteria in BREEAM are intended to apply to newly manufactured construction products and materials. Where a construction product can be robustly identified as previously used and is re-used or reclaimed, it may be considered as outside the scope of the Emissions from construction products criteria. However, any new coatings, finishes, adhesives, sealants, or other chemical treatments applied for the product’s installation must be considered and assessed separately, where relevant.

Emissions from products – Recognition of carcinogen classifications from non-EU schemes - KBCN1879

Where BREEAM material emission criteria reference Category 1A and Category 1B carcinogens, these classifications are based on the EU CLP Regulation. However, where a certification scheme or testing body does not work directly to EU CLP classifications, other recognised authoritative carcinogen classification systems may be accepted as an alternative basis for carcinogen identification. This can include: • International Agency for Research on Cancer (IARC) • California Office of Environmental Health Hazard Assessment (OEHHA)

Formaldehyde E1 emissions requirements – Untreated solid wood - KBCN1881

Testing for formaldehyde is not required for untreated solid wood where no formaldehyde containing binders, resins, adhesives, coatings, or chemical treatments have been used in the processing or manufacture. In such cases, a formaldehyde emissions test report is not required. However, the assessor must obtain confirmation from the manufacturer/supplier that:

the product is solid, untreated timber
no formaldehyde has been used as described above

Future thermal comfort – mechanical ventilation, mixed mode and limited comfort cooling - KBCN1877

Where a building or space incorporates mechanical ventilation systems, including mixed-mode strategies, the selection of future weather files for thermal comfort assessment should be based on the expected service life of the systems installed. This includes systems providing mechanical ventilation, with or without limited comfort cooling, and mixed-mode spaces where natural ventilation is supplemented by mechanical systems within the same space. For the purposes of this guidance, ‘mechanical ventilation with limited comfort cooling’ refers to systems that may provide some degree of cooling or air tempering but are not designed to fully maintain internal conditions to defined air-conditioned setpoints throughout occupied hours. Although these systems do not provide full air conditioning, their presence influences internal environmental conditions and overheating risk. As their performance is dependent on mechanical components with defined service lifespans, the future thermal comfort assessment should be aligned with the expected lifespan of these systems (typically 15 years), rather than the overall building lifespan. For schemes where free‑running buildings are assessed using a longer lifespan for future climate scenarios, a shorter system lifespan should be used where mechanical systems are present

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.

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.

Pods or privacy booths used as workstations – Impact on view out - KBCN1697

Provided the space or room itself is compliant based on a more traditional furniture arrangement, the enclosure of workstations in booths or pods can be disregarded when considering compliance with the ‘View out’ criteria.

User controls – Thermal comfort - KBCN1813

The requirement for user controls does not mandate a specific type of control; e.g. local manual adjustment. Where control is provided indirectly, e.g. via BMS or central management, the assessor must demonstrate that this approach meets the intent of the user comfort and accessibility criteria and is informed by end-user discussions or relevant design guidance. Please refer to KBCN0170 for clarification of the types of space requiring user controls.

View out – Bedrooms in Residential and Residential institutions - KBCN1798

The 'View out' criteria are generally not applicable to bedrooms in assessments of Residential and Residential institutions (long-term stay and short-term stay), where the occupants are likely to be elsewhere during the daylight hours. Although a multi-purpose desk or work surface may often be provided in bedrooms for short-term working, study and other uses, this would not normally be considered as a dedicated workspace. An exception to this would be where a separate dedicated office or study space is provided, for example within a bedroom suite. Please also refer to any building-type-specific guidance, as bedrooms in sheltered housing, for example, may be considered differently. It is the role of the assessor to determine whether individual spaces should be determined as ‘relevant building areas’ in accordance with guidance provided.

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.

View out – percentage area - KBCN0166

For the view out credit, compliance must be demonstrated for the percentage of the floor area in each relevant building area, rather than the percentage of the total relevant building area in the building.

09-Oct-2025 - Applicability to INC V6 standard confirmed. 
14-Feb-2017 Wording amended to clarify that the percentage must be achieved for each 'relevant building area'.

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.

View out – rooms used for security or other critical functions - KBCN1040

The View out criteria are not applicable to rooms containing security or critical systems or sensitive material, such as CCTV monitoring rooms. Where it can be demonstrated that the presence of compliant windows would compromise a critical function of the space, the criteria can be considered not applicable.

19-Feb-2025 - Scheme applicability updated. 
06-Mar-2018 - Published.

VOC credit issues – Clarification of scope - KBCN1797

The scope of these requirements does not include furnishings or moveable furniture, e.g. desks, seats or shelving. It includes fixtures and fittings that are integral to the building, such as kitchen units and toilet cubicles. However, bespoke fixtures, such as purpose-made items of fixed furniture, can be excluded, as the specified compliance testing is not appropriate for such items.

New Construction / International / V6 /

02 - Health and wellbeing