50%

10%

CN1 

Energy performance, criterion 1

Shell only: Calculate an Energy Performance Ratio just for the building’s heating and cooling energy demand only (EPR _ED). Compare the EPR _ED achieved with the EPR _INC in Table 26 with the EPR _ED substituted for the EPR _INC. Award the corresponding number of BREEAM credits.

The exemplary credits for this issue are not applicable for shell only.

Shell and core only: All assessment criteria relevant to the building type and function apply.

Refer to Appendix D – Shell and core project assessments of this Scheme Document for further description of the above options.

CN1.1

Where the building services efficiencies are not known, for example where they are not within the remit of the shell and core developer (i.e. where services will be provided as part of the fit-out works), services complying with the minimum energy efficiency standards or backstop levels required by the relevant national Building regulations should be used for the energy modelling.

CN1.2

CN2

Both options: All criteria relevant to the building type and function apply.

Refer to Appendix E – Applicability of BREEAM New Construction to single and multiple dwellings, partially and fully fitted for a more detailed description of residential assessment options.

CN3

Extensions to existing buildings

Where an extension to an existing building is being assessed, and that extension uses an existing building services system, the energy modelling and percentage of improvement must be based on the building fabric of the extension and building services system that will service the new extension. This includes any existing, shared and new plants that will serve the new extension area.

The energy modelling does not have to consider the existing building fabric where it will be out of the scope of the BREEAM assessment. Nor does it have to consider existing service systems where they are not supplying heating, cooling or ventilation to the new extension being assessed.

CN3.1

CN3.2

Where there is a NCM in the country of assessment, then Option 1 must be used to demonstrate compliance with this issue.

Where there is no National Calculation Method (NCM) in place OR where the NCM does not allow the design team to undertake an analysis of issues such as lighting or renewable energy generation, the design team may undertake a more thorough analysis of the performance of the building using alternative approved building energy calculation software (see CN3.3).

Option 2 is available for design teams if they choose not to carry out energy modelling of their building and where there is no NCM in place. However, because energy modelling is the preferred way to demonstrate that a building is energy efficient, a maximum of 10 credits is available using Option 2.

CN3.3

The notional building will be generated using EITHER:

1. Local building regulations or standards; OR
2. Appendix G Performance Rating Method of ASHRAE Energy Standard 90.1-2013 (for all buildings except low rise residential buildings) or ASHRAE Energy Standard 90.2-2007 (for low rise residential buildings); OR
3. A notional reference building as defined in the UK’s NCM. This option is only available where the building is located in a temperate climate (Köppen Geiger climatic zone Cfb).

Options 2 and 3 above are only available in countries where the local regulation is less rigorous than Appendix G of ASHRAE Energy Standard 90.1-2013 or the UK’s NCM.

CN3.4

All three performance metrics; demand, primary energy consumption and CO₂, generated by the approved building modelling software should be entered into the BREEAM scoring and reporting tool in order to calculate the Ene01 score, even if there are no mandatory requirements related to a particular metric in the country of assessment. For example, if the local building regulations only set a target with respect to primary energy consumption, but the approved software also reports figures for energy demand, both the figures for primary energy consumption and energy demand should be reported in the BREEAM scoring and reporting tool.

CN3.5

The output documents generated by the approved software may not include all three performance metrics required by BREEAM. Where this is the case, all of the metrics that are available must be entered into the scoring and reporting tool (see CN3.6).

CN3.6

While all metrics should be reported in the BREEAM scoring and reporting tool (see CN3.4), it should be noted that performance against the energy demand metric will only be considered in the calculation of the EPR_INC, where it makes a positive contribution. If performance against the energy demand metric lowers the EPR_INC, it will be automatically discounted from the calculation. The reason for this approach is to encourage the reporting of performance against the demand metric in all instances.

CN3.7

Where the chosen modelling or calculation tool accounts for the energy used for internal lighting, the maximum credits available for this BREEAM issue will be 15.

If internal lighting is not included within the modelling calculations, the credits available from modelling will be reduced and the remaining credits awarded for complying with the lighting criteria within Checklist A5as follows.

1. 12 credits will be available for residential buildings, with a further three credits available for compliance with the residential lighting criteria within Checklist A5.
2. 13 credits will be available for non-residential buildings with a further two credits available for compliance with the non-residential lighting criteria within Checklist A5.

CN3.8

CN3.9

At present there is no standard or national calculation methodology for modelling Equipment energy demands in a building. To demonstrate compliance with the ‘exemplary level criteria’ the building’s modelled Ene 01 Reduction of energy use and carbon emissions consumption is therefore used as a proxy for a building’s Ene 01 Reduction of energy use and carbon emissions demand, i.e. Ene 01 Reduction of energy use and carbon emissions equals 100% of Ene 01 Reduction of energy use and carbon emissions. While not accurate, this approach enables BREEAM to assess and award credits for a building that meets a proportion of its Ene 01 Reduction of energy use and carbon emissions demand via on site or near site renewable energy sources.

Where Ene 01 Reduction of energy use and carbon emissions demand for the building can be accurately predicted, then these data can be used to determine the percentage of Ene 01 Reduction of energy use and carbon emissions demand met via renewable energy sources. Ene 01 Reduction of energy use and carbon emissions demand could be estimated on the basis of metered data from a similar or the same building type with the same system or process loads or by using the methodology described in CIBSE TM54: 2013, 'Evaluating Operational Energy Performance of Buildings at the Design Stage, 2013' or other equivalent national best practice standards.

CN4

The Ene 01 calculation should be completed for each dwelling or each energy type or each energy group (see CN4.1). The energy performance ratio (EPR_INC) should then be area averaged for the whole development using the calculation procedure in Methodology for either Option 1 or 2.

Where the advised averaging method is deemed unsuitable for the approved building energy methodology, a new calculation can be approved; please contact BRE for guidance. An example is where a NCM considers energy consumption in communal areas as well as per dwelling.

CN4.1

A set of residences on a development are of the same ‘energy type’ if they have the same approved building energy calculation software outputs for performance data as outlined in criterion 2 . They will exhibit each of the following:

1. Approximately the same size, built form and construction details
2. The same space heating, hot-water system and controls
3. The same orientation and level of over-shading or sheltering
4. The same assumed or actual air permeability and ventilation system.

CN4.2

Energy groups only apply when a building contains multiple flats or apartments within the same building envelope. The performance data outlined in criterion 2 can be averaged across the whole building provided that the same building services strategy is adopted throughout. These dwellings are defined as an energy group.

Note: This averaging rule cannot be applied to individual, but adjoined housing and is subject to the following:

1. Where varying servicing strategies (including the provision of renewable energy systems) are adopted in the building, dwellings should be grouped by strategy
2. Each energy group must be treated separately for the purposes of assessment and an average Actual Building Emission Rate and Notional building emission rate are used to calculate the percentage improvement.

It is the BREEAM Assessor’s choice whether or not to use the energy groups averaging method or to complete the calculation for each individual dwelling.

CN4.3

The legislative criteria for energy modelling may vary according to building size, use, services and tenancy arrangement. In some instances modelling may be undertaken for the whole building; in others modelling may be undertaken for each individual unit or tenanted area within a building. The scope of a BREEAM assessment typically covers the whole building, regardless of whether that building consists of a number of units to be sublet.

Where energy modelling is required for each unit, for the purposes of determining the number of BREEAM credits, the EPR_INC (as required for Option 1) is calculated as the area-weighted average EPR_INC of each individual unit. Where the development contains conditioned shared or landlord spaces, the area of these spaces, unless otherwise accounted for, should be divided and attributed among the separate units. The proportion of shared areas attributed to each unit must be equivalent to the ratio of each unit’s area as a proportion of the total area of all units.

All units, heating systems and common areas within the assessed building must be accounted for in the assessment of Ene 01.

A copy of the report and output documents generated by the approved software for the assessed building at the design stage illustrating:

1. The actual, notional and BREEAM best practice building performance data

2. Name of the approved software used to carry out the modelling for calculating the energy performance
3. Confirmation of the expertise and experience of the individual carrying out the modelling in compliance with the requirements of the local building regulations

AND

Where appropriate, a letter from the person carrying out the modelling confirming:

4. Data used to model the notional building is taken from local building regulations, Appendix G of ASHRAE Energy Standard 90.1-2013 or the UK's National Calculation Methodology.

The output documents must be based on the 'as designed' stage of analysis.

Third party documentation, as follows:

1. Actual building energy performance certificate and the output documents of the approved software, required as part of demonstrating the as-built building complies with local building regulations, Appendix G of ASHRAE Energy Standard 90.1-2013 or the UK's National Calculation Methodology
2. As-built drawings to demonstrate that the specification used and modelled at the design stage matches the specification of the completed building
3. Calculations associated with averaging, where it has occurred. The final rating must account for any changes to the specification during construction.

2 –3

A completed copy of Checklist A5.

The relevant specification clauses confirming details of compliance with each requirement.

A letter from the building services engineer confirming items selected from the checklist are appropriate for the building type and local climatic conditions.

A copy of a report, calculations or outputs from the manufacturer, supplier, engineer or software modelling confirming:

1. The total LZC energy generation (kWh/yr)
2. The source of the LZC energy
3. The calculated estimate of the 'Equipment energy’ consumption from systems or process (kWh/yr) (required only if confirming an Energy positive building)
4. The calculated estimate of exported energy surplus (required only if confirming an Energy positive building).