09 - Pollution - BREEAM Knowledge Base

Adoption of road in the development - KBCN0331

Where a development includes roads, these are often adopted by a statutory authority (for example the Highways agency or the local authority in the UK). Where the authority will be taking responsibility for the roads, the following guidance should be followed to determine if the water run-off from the roads needs to be considered as part of the assessment:

If the road drainage system bypasses the new development's network to connect directly to the local drainage network, then the water running off from the roads does not need to be considered for this assessment. Evidence will need to be provided to demonstrate if this is the case.
If the road drainage system connects to the development drainage network before connecting to the local drainage network, then the water run off from the roads must be considered for the assessment.

Where the authority will NOT be taking responsibility for the roads, the BREEAM criteria should be followed for all drainage on site.

Applicability of prerequisite - KBCN1072

The prerequisite must be met in order to award any credits where refrigerants are used. It is also applicable when the 'leak detection' credit is awarded on the basis of the refrigerant charge being less than 6kg. For refurbishment projects, this pre-requisite applies only to newly specified or upgraded systems in the scope of works.

10.08.22 Added clarification for RFO projects.

Backup or emergency heating systems - KBCN0936

NOx calculations should be based on permanent heating systems and should not include backup systems used for maintenance or in emergencies. BREEAM assessments measure the as designed performance level of the building as it normally functions.

Campus with multiple building assessments - KBCN0597

If a campus development project has multiple building assessments being built in conjunction with each other, each building should be assessed independently. Where there are noise sensitive buildings; including any new buildings in the process of being built, the criteria requirements must still be met.

CHP NOx emission conversion - KBCN0592

If the CHP manufacturer cannot provide the NOx emissions in mg/kWh it is not possible to award any credits. The CHP manufacturer must provide the NOx emissions in mg/kWh, the conversion factors provided in the Technical Manual can only be used for boilers.

CN 3.3 Low NOx grid electricity - KBCN0886

CN3.3 was accidentally copied in the reissue v.2.0 and should be ignored. It will be removed in the next reissue.

Technical manual to be updated accordingly in next reissue.

Compliant attenuated noise levels - KBCN00047

BS 4142 noise level requirements can be used to demonstrate compliance provided the best practice testing methodologies for noise attenuation outlined in BS 7445 are followed.

District cooling – Used in combination with local cooling - KBCN1634

Where district cooling can be considered outside the scope of the assessment, either in accordance with the Methodology section of the technical manual or in line with KBCN0759, compliance must be based on calculating the DELC for all systems. However, where the district cooling system is exempt from assessment, as described above, this should be based on a GWP of zero for the district cooling system.

District cooling systems - KBCN0759

Where a district cooling facility is servicing the assessed building, the building will have an environmental impact in terms of refrigerants, albeit in this case indirectly. As such the district cooling system must be considered against the BREEAM criteria for refrigerants. Where connection to an off-site district cooling system, over which the developer has no control, is mandated by a local authority or other statutory body, the maximum number of credits can be awarded for Issue Pol 01. However, where this is not mandatory and the developer has the option whether to connect, regardless of encouragement or incentives by the local authority, the district cooling system must be considered against the BREEAM criteria for refrigerants to award the credits.

07 Dec 2023 - This KBCN is not applicable to UK NC2018 or UK NC V6 - Guidance is provided in the Methodology section of the technical manual.
27/04/2017: Clarified the number of credits awarded

District heating systems - KBCN0979

District heating systems serving the assessed building must be assessed for NOx emissions.

Where the developer has no choice over this connection, the maximum number of credits available for the asset type is awarded for this issue. For instance, the connection is mandated by a local authority or other statutory body.
Where the developer has choice over their connection, the district heating system must be assessed against BREEAM criteria. This is regardless of any incentives to connect.

14-Dec-24 - Wording clarified.
07-Dec-17 - Reference to NOx emissions clarified

District heating systems which off-set grid electricity - KBCN0857

District heating systems which incinerate waste usually have NOx emissions higher than the levels set to achieve any BREEAM credits. However, where a district heating system also generates electricity, this can be used to off-set NOx emissions from grid electricity. In such cases, the calculation methodology for CHP systems can be used to calculate NOx emissions for the district heating network.

Emissions – measuring heating demand - KBCN0182

Emissions for all heat sources should be measured under normal operating conditions which are when all heat sources from the building plant are operating to their maximum design heat outputs to meet the building's heating demands. Where plant is designed to operate below maximum capacity, for example multiple or modular systems or standby boilers,the emissions should still be calculated for the plant operating to meet the building’s heating demand. Any redundant capacity or standby plant should not be included.

Extension using existing building services - KBCN0914

When assessing an extension, which is served by existing building plant, the existing plant, should be considered as contributing to the existing pre-development background noise level. Any additional plant or changes to the operation of the existing plant should be considered as a new noise source. This Issue seeks to address any increase in background noise levels which result from the assessed development.

22/02/2018 Wording amended to clarify how existing plant should be considered

^{Superseded wording}^: ^{Existing building services serving a building extension have to be included in the assessment of this issue.} ^{Issue Pol 05 is applicable to all treated buildings, even where existing building services are used for an extension building, without being upgraded. The issue assesses the impact on any nearby noise-sensitive buildings of existing and newly specified plant and the effectiveness of any fabric measures to reduce this.}

External lighting inside wider building - KBCN0906

Where a building undergoing assessment is located inside of another building, for example a retail unit within a shopping centre, Ene 03 External lighting and Pol 04 Reduction of night time light pollution should be assessed as follows; Ene 03 'External lighting' that is inside of the wider building, using the example above the lighting is external of the retail unit itself but inside of the wider shopping centre, criteria relating to the luminous efficacy should be applied as presented within the manual. For the criteria relating to controlled for prevention of operation during daylight hours and presence detection in areas of intermittent pedestrian traffic, however, instead of demonstrating that the lighting is not operational during daylight hours, it should be demonstrated that the lighting is not operational outside of the operational hours of the wider shopping centre. Any external lighting within the scope of works being assessed that is located outside of the wider shopping centre, for example if the retail unit had an entrance or exit that leads on to the street outside, this would need to be assessed against the criteria presented within the manual. Pol 04 If the building undergoing assessment has no external lighting that is outside of the wider building, it can be considered that the building has no external lighting. However, as above, any external lighting within the scope of works of the assessment that is located outside of the wider building will need to be assessed as the criteria is presented within the manual.

10/05/2019 Reference to specific criteria numbers removed and made applicable to UK NC2018

Flood Resilience - KBCN1478

In order to award two credits

Flood risk must be determined by a compliant, site-specific Flood Risk Assessment and cannot be based solely on on EA Flood Maps
The credits for flood risk are awarded based on the pre-development site

Sites which have a medium or high flood risk from one or more sources (pre-development) can only achieve one credit, subject to mitigation measures being implemented as part of the development. The criteria seek to encourage the development of sites in areas of low flood risk from all sources.

01/11/2021 Clarified: 'Sites which have a medium or high flood risk from one or more sources...'

Flood risk – Site situated across numerous flood zones - KBCN0532

Where a site is situated across more than one flood zone, the flood zone with the highest probability of flooding, i.e. the worst case scenario, must be considered for the purpose of the BREEAM assessment. An exception to this would be where the areas in the higher probability zone include only soft landscaping and it can be demonstrated that access to the building will be maintained in a flooding event. This is to ensure that the site has adequately managed the worst case scenario level of flood risk associated with the site's location.

22/07/2022 Applicability to HQM One confirmed
07/03/2018 Updated to include circumstances where an exception may apply.

Freestanding commercial fridges and freezers - KBCN0577

Freestanding commercial fridges and freezers must be included in the assessment of the Pol 01 issue, even when they are not connected to the building cooling system. Only domestic white goods are excluded from the assessment of this issue.

Greenfield/Brownfield site – Definition - KBCN1259

For the purposes of this Issue, the following definitions apply: Greenfield site A site which has never been built on, includes minimal development or which has been substantially cleared of all buildings and associated fixed surface infrastructure* and has subsequently remained undisturbed for five years or more. * Typically, the site includes less than 5% residual development by area. This supersedes the definition of 'Greenfield' for this Issue in the technical manual. Brownfield site Any site which does not fall within the above definition of 'Greenfield site'

Heat pumps powered by renewable energy - KBCN0422

Where renewable energy is used partially to offset grid electricity in heat pumps, this can contribute towards a reduction in equivalent NOx emissions. To account for seasonal variations in renewable energy generation, this must be calculated over the course of a year.

Impact of refrigerant – Refrigerants with low GWP - KBCN1472

Where systems only use refrigerants with GWP ≤ 10 The Pol 01 calculator does not have to be completed. Providing evidence of the compliant systems and refrigerants used is enough to award maximum credits for impact of refrigerant. Mix of systems with GWPs below and above 10 The Pol 01 calculator does have to be completed. The calculator must include systems with GWP ≤ 10 to ensure credits are based on the average value across all systems.

20-Dec-2023 Updated to include scenarios where there is a mix of systems with GWP above and below 10.

International suitably qualified professionals - KBCN1266

In some issues the International NC and RFO schemes prescribe specific requirements for suitably qualified professionals. We appreciate that some countries might have different recognition schemes in place, and these might differ from the BREEAM requirements. Where this is the case, assessors should submit a technical query with appropriate information, and we will review and approve each situation on a country basis.

Leak detection system based on pressure changes - KBCN0326

A system that uses pressure changes to detect leaks is not necessarily compliant. To be deemed compliant the leak detection system would need to monitor the refrigerant pressure and the operating conditions to address the problem of natural fluctuation.

LZC technologies – energy centre or other LZCs connected at a later stage - KBCN0267

If a project specifies LZCs that have been proposed in the feasibility report which reduce emissions, and/or will be connected to a site-wide energy centre operational at a later stage of the phased development, after the Post Construction Stage review has been submitted, the Energy and Pollution issues can be assessed as follows: In a phased development where the primary heating system will be upgraded at a later stage than the building being assessed, a commitment to install the new heating source must be made in the General Contract Specification (as per the BREEAM requirements). BREEAM does not specify a particular time for phasing as it is difficult to set parameters, however as a rule building users should have to wait the least time possible before they can use the upgraded heating source. For the quality audit, two Energy model outputs/EPCs must be produced at the final stage - one with the actual interim system installed for building control, and one for the BREEAM assessment which can include the predicted energy from the proposed energy centre. Additionally, the legally binding general contract specification for the new heating source must be submitted with details of the timescales proposed for the completion of the second phase of work. Where this approach is to be followed BREEAM must be consulted in each case to ensure that the arrangements are sufficiently robust to award the credits. BREEAM seeks to recognise the environmental impacts of a building's energy use throughout its life, therefore temporary arrangements can be accommodated, provided there is robust evidence on future connection to the permanent systems.

24/08/2022 - Applicability to UKNC V6 confirmed

Manufacturer’s information – system specific data - KBCN0926

The BREEAM technical manual provides a set of default figures, for use within the DELC calculation. Where available, system-specific data, provided by the manufacturer, can be used in the calculation where this is more representative. Any such system-specific figures used must be supported by publicly available, published data, which substantiates the manufacturer’s figures.

Minimising water course pollution – no water courses present - KBCN0550

The credit for 'minimising water course pollution' has to be assessed even in cases where no water courses are in close vicinity to the site under assessment. This is because the aim of this credit is to encourage developments to minimise water course pollution by restricting the discharge of potentially contaminated water from entering the public sewer. Minimising water course pollution does not focus on water directly entering water courses.

Missing criterion – external lighting standards - KBCN0883

The following criterion, included in the BREEAM INC 2013 scheme, was omitted in error from the BREEAM IRFO 2015 and BREEAM INC 2016.

The external lighting strategy has been designed in compliance with the limits set for light technical parameters in section 2.7 of CIE 150-2003 and table 2 of CIE 126-1997.

Projects registered after the announcement of this KBCN in the July 2017 Process Note must comply with this and other relevant criteria within Pol 04 in order to achieve the credit.

Technical manual to be updated accordingly in next reissue.

No discharge for up to 5mm rainfall - KBCN0599

The criterion requires no run-off to leave the developed site into the local watercourse(s) for a storm event that results in rainfall depths up to 5mm. It is not acceptable to collect the rainfall within an attenuation tank and allow the runoff to be released from the site at a restricted rate. This simply slows the rate at which it is released to the watercourse(s). The 5mm rainfall event is considered one of the most common rainfall events and, therefore, a system should be designed to prevent this run-off leaving the site thus protecting a receiving watercourse from pollution.

No external plant specified - KBCN0931

Where there is no external plant specified and the acoustician confirms that there is no significant noise source, it is acceptable for the acoustician to provide a formal statement in lieu of the noise impact assessment. All other evidence for this issue must be provided as listed in the Evidence table. The formal statement should be produced by a 'suitably qualified acoustician' (as defined in the Relevant Definitions for this issue) and should justify this approach with reference to the specific internal plant to be installed and the proximity of any noise sensitive areas or buildings. The statement must explain clearly how the aim of the issue is being met.

No refrigerant use – shell & core assessments - KBCN1058

The credits for Pol 01 can be awarded if the asset requires no refrigerants as per the criteria. In speculative assessments, future tenant systems are unknown. To award the credits, evidence must show that the asset has been designed to operate without the need for air-conditioning or comfort cooling for the conditioning of occupied spaces. One way to demonstrate this is to achieve the ‘Free cooling’ credit. Only refrigerants used for occupant comfort are assessed. Do not assess any refrigerant use for process-related functions.

21.09.2021 Wording amended for clarity

Not enough rows in the Pol 01 calculator - KBCN1274

If additional rows are required in the calculator, it is acceptable to add the specification of multiple models together in one tool, provided they are the same model and have all the same inputs for columns F to M. The weighting of the systems across the building is done by the System Capacity and Total Refrigerant Charge (columns E and F), so you would multiply each of these two figures by the total number of the system specified. This gives the contribution of the systems to the building's cooling capacity and charge. If further rows are still required please submit a query using the webform in BREEAM Projects, attaching a copy of the tool and specify the number of additional rows required.

08/10/21 link to webform added

Pol 01 Prerequisite – Applicable standards - KBCN1537

ASHRAE standards (ASHRAE 15-2016 'Safety Standard for Refrigeration Systems' or ASHRAE 34-2016 'Designation and Safety Classification of Refrigerants') can be used in place of the ISO/EN standards referenced in the prerequisite. This is only applicable to countries outside Europe.

Post construction noise level testing - KBCN00043

Noise level measurements do not need to be taken at the post construction stage if the acoustician has accurately modelled the noise level from the plant, using manufacturer's literature, and site measurements taken at the design stage. Any attenuation measures specified by the acoustician in their report must be confirmed as being present post construction. If the acoustician has been unable to model the noise level accurately, post construction measurements are needed to demonstrate compliance. Calculations and recommendations from the acoustician are relied on to be accurate and in keeping with best practice; attenuation measures are assumed to be specified and installed correctly.

Reduction of night time light pollution – Night-time operation - KBCN0697

Note: This KBCN supersedes INC 2016/INC V6 Pol 04 CN3.1 During hours of operation between 23:00 and 07:00, lighting required for operational reasons does not have to be modified for BREEAM compliance. The aim of this Issue is to reduce light pollution by automatically switching off the external lighting or by complying with lower levels when the building is not in use.

23 Jan 2023 - Note added to address conflict with INC Pol 04 CN3.1. KBCN title updated for consistency - The technical manual will be updated accordingly in the next re-issue
008 Mar 2018 Wording amended to add clarity.

Reversible heat pump (VRF) providing both heating and cooling - KBCN0735

Where a reversible heat pump, which provides heating and cooling on reverse cycle with heat recovery, is used, the cooling capacity only should be used for the Direct Effect Life Cycle CO_2e emissions (DELC) calculation. The cooling capacity of heat humps is normally less than the heating capacity, so compliance against the criteria will be based on the more challenging DELC value calculated.

Safety and security lighting – definition - KBCN0888

BRE does not provide a specific definition of safety and security lighting, as this could vary, depending on the project and location of the lighting. Together with the design team, the assessor is required to determine which lights are provided purely for safety and security purposes and which should be considered as general lighting.

Scope of issue – clarification – fixed installations - KBCN1660

The scope of this issue covers noise from external building services (or 'fixed installations' as written in the manual) serving areas designed for human comfort. The noise impact assessment excludes:

Noise from process-related plant.
Noise from emergency or back-up plant which are not used during normal operation.

Scope of the refrigerant leak detection system - KBCN0530

The refrigerant leak detection system is required to cover any part of the plant or pipework which contains refrigerant.

21/08/17 KBCN amended to include pipework containing refrigerant.

Surface water run-off – no change in impermeable area - KBCN1212

CN 3.9 states: "Where the man-made impermeable area draining to the watercourse (natural or municipal) has decreased or remains unchanged post-development, the peak and volume rate of run-off requirements for the surface water run-off credits will be met by default… In this instance a flood risk assessment must be carried out and any opportunities identified to reduce surface water run-off are implemented." Where the flood resilience credits are not being targeted, a flood risk assessment is not required. Instead, a separate study identifying opportunities to reduce surface water run-off may be carried out, and the measures implemented. Where there is no change in impermeable area, opportunities should be identified to reduce run-off. It is not necessary to carry out a flood risk assessment to fulfill the intent of this criteria.

Surface water run-off not flooding property - KBCN0565

Where parts of a site may flood in the event of local drainage system failure, it is still possible to demonstrate compliance if the building itself will not be at risk of flooding.

Table 58 and CN3.2 Grid electricity amendments - KBCN0887

Table 58 and the third paragraph in CN3.2 were accidentally copied in the reissue v.2.0. Table 58 should be ignored and the compliance note should read as follows: CN3.2 Grid electricity Heating systems powered by grid electricity can be considered to have zero NOx emissions. If all heating in the building is provided by grid electricity the credits can be awarded by default. The reason for this is based on the aim of this issue, which is to improve local air quality.

Technical manual to be updated accordingly in next reissue.

Temporary power solutions in noise impact assessments - KBCN0171

Plants such as standby generators that are only used temporarily are excluded from the noise impact assessment.

Verification of measurements undertaken by non-SQA - KBCN1661

It is acceptable for individuals who do not meet the BREEAM definition of a suitably qualified acoustician (SQA) for Pol 05 to undertake the testing for this issue, provided the measurements or calculations are verified by a SQA. The SQA must review the report and confirm in writing that they have found it to:

Represent sound industry practice
Be appropriate given the building being assessed and scope of works proposed
Avoid invalid, biased and exaggerated recommendations

Additionally, written confirmation from the SQA how they comply with the definition of a SQA is required.

Watercourse pollution from indoor parking - KBCN0545

If the design team can demonstrate that there will be absolutely no run-off from the indoor parking then the intent of the credit will be met. However, such proof would also have to demonstrate that no hydrocarbon spillage from vehicles found its way into the watercourse/sewer. It is likely that there would be water ingress from outside or that internal parking areas would have drains fitted and be cleaned regularly. In such conditions, the criteria are still applicable. The intent of this criteria is to ensure no hydrocarbons run off to any watercourse.

[KBCN Withdrawn] ~ Confirmation of low flood risk without an FRA - KBCN0582

The KBCN has been withdrawn and is no longer valid. This is because its content was created on the basis of a very specific case and should not be applied generally. The authority/organisation's confirmation is no more robust or detailed than reference to flood maps, which are not in themselves compliant without a FRA.

KBCN withdrawn on 31/03/17:

Where a national or local authority/organisation has confirmed, in writing, that the site has a low risk of flooding from all sources and that a Flood Risk Assessment (FRA) is not required then this is acceptable and the two credits can be awarded.  The authority/organisation's written confirmation is a sufficient indication that an appropriate level of flood risk assessment has been completed.  Please note that the use of relevant flood maps without this additional confirmation from the authority/organisation is not acceptable.

New Construction / International / 2016 /

09 - Pollution