02 - Energy - BREEAM Knowledge Base

Centralised air handling units (AHU) - KBCN0941

The requirements of the:

Second sub-metering credit (New Construction).
Issue (BREEAM In-Use).

do not apply to centralised AHUs, where it is not technically feasible to sub-meter energy use by separate functional, tenanted or floor areas. The credit(s) will be assessed based on the remaining applicable energy uses.

06-Mar-2024 - Scheme applicability extended to V6.

Clarification – access to daylight - KBCN1648

Q11 of this issue asks 'what percentage of lit asset floor area has access to daylight?' For this issue, 'access to daylight' means: Spaces daylit from the side

Is within 8m of a wall with openings that allow daylight in AND
Openings comprise ≥ 20% of the wall area, as viewed from the inside. For windows, the opening size is defined by the inside edge of the window frame, ignoring any transoms or mullions in the glazed area itself.

Spaces daylit from above

Any spaces, or parts of a spaces illuminated by overhead openings, light tubes, or other daylighting strategies. Where the daylighting strategy only covers part of a space, the assessor can use their judgement to define which areas have 'access to daylight' based on the specific design and lighting conditions.

Clarification – percentage of end uses - KBCN1650

This percentage is measured by the energy consumption (kWh) of significant energy uses, not by the number of end uses.

Combined sub-metering – electric space / water heating and small power - KBCN00068

For bedrooms and associated spaces in:

Multi-residential or residential institution building types (New Construction).
Hospitality or supportive housing asset types (BREEAM In-Use).

It is acceptable for an electric space or water heating system to be combined with lighting and small power, provided that sub-metering is provided for each floor plate or other appropriate sub-division. For these asset types, sub-metering electric heating in multiple bedrooms may be costly and technically challenging. Where occupants have individual control but are not responsible for paying the utility bills, the building manager may have little influence on their energy consumption. Therefore, sub-metering electric heating would provide little or no benefit in meeting the aim of the issue.

06-Mar-2024 - Scheme applicability extended to V6. 
15-Dec-2023 - Title updated to clarify that this approach can be applied to both space heating and domestic hot water heating, where appropriate.

Combined system for heating / cooling and domestic hot water - KBCN0329

It is permissible to have combined metering for a shared on-site or district system that combines heating / cooling, and domestic hot water generation. In all cases, justification is provided in the QA report for the combined metering, and explains why it is not technically feasible to provide separate meters.

21-Sep-2022 Applicability of KBCN added to BIU V6. Amended to include district heating and cooling networks.

District heating / cooling / hot water – entering data into the Online Platform - KBCN1536

For assets which use district heating / cooling / hot water, information on the district systems are entered into Ene 09a and 09b. In Ene 05 / 06 / 09, answer 'no' to first question "Is space heating / cooling / hot water generated on-site?" then navigate to:

Ene 09a to answer questions on district cooling.
Ene 09b to answer questions on district heating and hot water. A district heat network will also provide hot water, so information on the system which provides both is entered into Ene 09b.

The Online Platform differs from the manual structure, however it does not affect scoring in any way. All data entered contributes to the asset energy calculator. Assets with on-site and off-site systems Only answer questions on the system which provides the most signifcant heating or cooling to the asset. If an asset includes both on-site and off-site systems, choose the one which delivers the most energy annually.

Emergency lighting - KBCN0185

Maintained systems featuring emergency light fittings which are also used for normal operation, are assessed for this issue. Non-maintained lighting which is only activated in an emergency can be excluded from the assessment. NC / RFO / BIU V6 Ene 17: The aim of these credit(s) is to encourage and recognise energy-efficient fittings. Non-maintained emergency lighting will very rarely be activated and in such extremes the emergency requirements must not be compromised. BIU V6 Hea 05: Flicker is eliminated from maintained systems only.

24-Jan-2024 - Scheme applicability updated to include BIU V6.

Erratum – scope of issue - KBCN1498

Criterion 1 states: "Where external lighting or car park lighting are not necessary from a safety perspective, the associated credits can be filtered out of the assessment." What this means is:

Where external lighting does not exist, filter out the relevant credits.
Where car park lighting does not exist, filter out the relevant credits.
Whether or not the lighting exists for safety reasons has no effect on credit filtering.

The inclusion of the word 'safety' in this criteria is misleading and will be removed in future versions.

28-Feb-2024 - Wording clarified.

Erratum – up to V6 – methodology – no default energy assumptions - KBCN1630

The scope of the issue applies only to systems with significant energy use. The methodology section states that the online platform will calculate default values, and use this to indicate which systems are in scope. This is incorrect, as default values are not automatically calculated. The energy use of each system will need to be manually estimated. This can be done based on:

Typical benchmark values, and / or,
Estimates based on the capacity of equipment, and annual equivalent full load hours of use.

Erratum – V6.0.0 – cooling efficiency parameter – EER / SEER - KBCN1560

In the asset energy calculator guidance, the parameter given for cooling efficiency is 'SEER' (Seasonal Energy Efficiency Ratio). This is incorrect and should say 'EER'.

This affects the following tables:

	International	USA
Commercial V6.0.0	Table 19	Table 18
Residential V6.0.0	Table 16	Table 16

This will be updated in the next manual re-issue.

Interlock controls – clarification - KBCN1491

An interlock is a control that is wired so that when there is no demand for heating / cooling in a space, the heating / cooling generator and the associated pumps are switched off. Use of thermostatic radiator valves (TRVs) alone does not provide interlock. Partial interlock means that the cooling and heating interlock controls are separate. However, the control function may be set up to minimise the possibility of simultaneous heating and cooling. Total interlock means the controls are wired so that simultaneous heating and cooling is not possible. Where there are separate local heating or cooling units present, these will also need to be wired into the control system for total interlock to avoid the possibility of simultaneous heating and cooling.

On-site LZC – whole site shared connection - KBCN1424

To be recognised in BREEAM, the on-site Low and Zero Carbon (LZC) technology must have a direct physical connection to the assessed asset. OR Where the LZC technology is;

Located on the same site,
Is owned and managed by the same organization as the assessed building, and
Where it is impractical to physically connect the assessed building to the system,

It is acceptable to allocate the renewable energy generated proportionally as a calculation of the asset's predicted energy consumption compared to the total energy consumption of the whole site. To allocate renewable electricity by proportional consumption:

Obtain the total annual renewable electricity generated on-site.
Exclude all renewable electricity which has been exported to the grid.
Determine the respective electricity consumption of all assets on the whole site (predicted for new builds and measured for existing assets).

Where consumption data is missing, renewable electricity must not be allocated to the assessed asset. In this case, it is assumed that all electricity consumed is sourced from the grid.

17-Jan-2024 - Applicability BIU V6 Ene 13 removed, as this approach is not applicable to assessing the area of PV fitted.
21-Dec-2022 - Applicability to In-Use V6 confirmed.
24-Aug-2022 - Applicability to UKNC V6 confirmed.

Scope of the criteria for lifts – Small service lifts (dumbwaiters) - KBCN1589

Small service lifts, of the type typically used to transport prepared food and crockery in restaurants (sometimes referred to as 'dumbwaiters'), fall outside the scope of this assessment issue.

Single tenant - KBCN1640

Where the assessment area is only occupied by a single tenant, the issue is not filtered out. All relevant credits apply. The criteria is designed to recognise efforts between the asset owner and tenants to coordinate sustainability policies and resource monitoring. This principle is not affected by having a single tenant, even if they might act in the role of a managing occupier.

Systems serving <10% overall floor area - other affected issues - KBCN1542

The methodology for Ene 01 states: "Heating / cooling systems can be excluded from the calculation where the heated or cooled area equates to less than 10% of overall floor area." Systems which heat or cool < 10% overall floor area are not assessed in:

Ene 01 Building services.
Ene 05 Cooling.
Ene 06 Heating.

Ene 01, 05 and 06 all feed into the asset energy calculator and so their inputs must be consistent. All other issues relating to these excluded systems are still assessed such as:

Ene 11 Installed controls.
Ene 15 and 16 Monitoring energy issues.
Pol 03 Local air quality.
Pol 04 Global warming potential of refrigerants.

Thermographic survey – Standards for test method - KBCN1578

The appropriate international standard for thermographic surveys is ISO 6781:1983 Thermal insulation – Qualitative detection of thermal irregularities in building envelopes – Infrared method. The following are acceptable alternative standards:

EN 13187:1998 Thermal performance of buildings – Qualitative detection of thermal irregularities in building envelopes – Infrared method

In-Use / BIU International Commercial V6 / Part 1 /

02 - Energy