New Construction / International / 2016 / 03 - Energy /
ENE 01 - Reduction of energy use and carbon emissions
Information correct as of 7thMarch 2021. Please see kb.breeam.com for the latest compliance information.
Best Practice Specification - KBCN0763
The methodology intends to shape the best practice building into a single universal building specification that could be seen as best practice across all countries. Therefore energy performance is compared purely on physical information of buildings and relevant building systems.
The BREEAM Best Practice Specification is used only to calibrate how credit scoring in Ene 01 is calculated for each country, allowing comparability between buildings.
Where typical best practice differences exist between different building types, like for like comparisons are retained for buildings within each building type.
Best Practice Specification – actual U-values exceed best practice - KBCN1075
Where the actual building's thermal fabric performance (U-values) exceeds the BREEAM Best Practice Specification (BPS), resulting in better thermal performance, the BREEAM Best Practice Specification building will need to be modified to match the actual building's U-values, as stated in Guidance Note 25.
For instance, if the actual building's roof U-value was 0.10 W/m2K, but the BPS was 0.15 W/m2K, the BPS building will need to be modified to include a roof with a U-value of 0.10 W/m2K.
Best Practice Specification – additional costs for new energy modelling - KBCN0766
The procedure for modelling the BREEAM Best Practice Specification is not designed to be difficult or complex.
It requires the energy modelling specialist to update the specifications of the modeled building with the performance values of the BREEAM Best Practice Specification, re-run the simulation to provide the energy indicator results and save the model file.
This step does not require any change to the geometry or building systems. It is understood that for large or complex projects, the change of performance specification and additional simulation run time will result in some additional work, however in relation to the overall scale of the project this is not considered a major disruption to workflow.
Best Practice Specification – shell only - KBCN0764
For shell only projects, 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. The best practice specification should be used in the same way as for fully fitted buildings.
Best Practice Specification – values for different climatic zones - KBCN0765
Best practice building specifications for different climate zones do not currently exist but will be considered for future updates.
Calculating EPR where there are multiple BRUKLs - KBCN1083
Where more than one BRUKL is produced for a development, which is registered as a single assessment, an area-weighted average should be used to calculate the number of credits to be awarded. This does not apply where the ‘similar buildings’ approach is used.
Each of the energy performance outputs from the BRUKL (actual CO2
etc.) must be area-weighted to produce area weighted average values which are entered into the scoring and reporting tool. When applying this method, please include your area-weighting calculations and outputs as supporting evidence.
The following provides an example of an area-weighting calculation for two building areas A and B, each of 500m2
, for which separate BRUKL are available:
For building area A:
Notional building heating and cooling energy demand: 230 mJ/m²
Actual building heating and cooling energy demand: 200 mJ/m²
Notional building primary energy consumption: 300 kWh/m²
Actual building primary energy consumption: 280 kWh/m²
TER: 40 kg CO₂-eq/m²
BER: 30 kg CO₂-eq/m²
For building area B:
Notional building heating and cooling energy demand: 150 mJ/m²
Actual building heating and cooling energy demand: 140 mJ/m²
Notional building primary energy consumption: 200 kWh/m²
Actual building primary energy consumption: 190 kWh/m²
TER: 40 kg CO₂-eq/m²
BER: 38 kg CO₂-eq/m²
Area-weighted values for building areas A and B (of total floor area 1000m2
Notional building heating and cooling energy demand: 230*500/1000 + 150*500/1000 = 190 mJ/m²
Actual building heating and cooling energy demand: 200*500/1000 + 140*500/1000 = 170 mJ/m²
Notional building primary energy consumption: 300*500/1000 + 200*500/1000 = 250 kWh/m²
Actual building primary energy consumption: 280*500/1000 + 190*500/1000 = 235 kWh/m²
TER: 40*500/1000 + 40*500/1000 = 40 kg CO₂-eq/m²
BER: 30*500/1000 + 38*500/1000 = 34 kg CO₂-eq/m²
These area-weighted values are then used to calculate the overall EPRNC
31/10/2018 KBCN clarified. Reference to EPRs and calculation example added
Ene 01 software submission - KBCN0434
In countries with an existing National Calculation Methodology (NCM), the tool(s) approved for use under the NCM can be used as approved building energy calculation software without our prior approval, provided that the software conforms the following modelling requirements as set out in Directive 2002/91/EC on the energy performance of buildings (16 December 2002):
(a) thermal characteristics of the building (shell and internal partitions, etc.) which may also include air-tightness;
(b) heating installation and hot water supply, including their insulation characteristics;
(c) air-conditioning installation;
(e) built-in lighting installation;
(f) position and orientation of buildings, including outdoor climate;
(g) passive solar systems and solar protection;
(h) natural ventilation;
(i) indoor climatic conditions, including the designed indoor climate.
Where the design team wishes to use an alternative modelling software package, the assessor should first check the Approved Standards and Weightings List to see if the software is listed there. If the software cannot be found in the ASWL, please download and fill out the Ene 01 Approval for Energy Software form from the BREEAM Extranet, and submit this to the BREEAM technical team via email@example.com
, along with the appropriate evidence.
25/09/2017 Clarified to include requirements of Directive 2002/91/EC
Energy consumption and carbon emissions of untreated spaces - KBCN00049
Where the assessment contains a mix of treated and untreated spaces, untreated spaces can be excluded and the performance based on the treated spaces only. Where the entire assessment is untreated, the whole of the structure(s) must be assessed on the basis that this issue is critical for certification.
BREEAM is primarily designed to assess permanent, treated and occupied structures. Untreated structures are unlikely to gain many credits when being assessed.
Energy performance assessment for part of a whole building - KBCN0596
If the assessment is only covering part of a whole building, the energy performance assessment must be representative of the part of the building being assessed. Simply taking the energy performance assessment of the whole building would not therefore comply, especially if the non-assessed parts of the building were of a different use. A separate energy assessment of the part of the building is likely to be required.
The energy performance assessment must be representative of the parts of the building being assessed.
GN25 BREEAM International New Construction 2016 Ene 01 Calc - KBCN0722
A new calculation methodology for determining the number of credits achieved in Ene 01 was introduced in BREEAM International New Construction 2013. The core principles of this methodology have been retained in BREEAM International New Construction 2016, but there have been some changes to the way in which the methodology is implemented. This guidance note describes the main Ene 01 methodology and provides further detail on how it is implemented in the 2016 scheme.
View full Guidance Note
(licensed assessors only)
View all Guidance Notes
(licensed assessors only)
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.
Internationally approved Ene 01 calculation software - KBCN1177
The following calculation software are approved internationally and can be used provided local weather files are available in the country of the assessment.
Please make sure the approved version, in brackets, is used. If you wish to use a different one, please submit a technical query to BREEAMtechnicalcs@bre.co.uk
providing details of the changes.
- IES VE (all versions from 2014 onwards)
- Design Builder (4, 5, 6)
- TRNSYS (17, 18)
- eQUEST (3.63b, 3.64)
- Energy Plus (3, 6, 7, 8)
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.
NCM does not cover a building type - KBCN0686
If the NCM does not cover a building type or the Shell Only / Shell and Core project types, assessment using "Option 1 – Use of approved building energy calculation software" can still be used according to the guidance given in the technical manual.
The generation of the notional building can be done by using the 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). Any imperial units used in the standards are to be converted to metric first before they are used in any calculations.
Prior to taking this approach the assessor should be satisfied that the NCM does not cover the assessed building type, and relevant evidence should be submitted to demonstrate this.
For International 2013 assessments where ASHRAE Appendix G is used, regardless of the robustness of local regulations the correct Ene 01 translator curve used is "2. Good International Practice."
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 building.
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 energy generated from this technology to the assessed building proportionally as a calculation of the building's predicted energy consumption compared to the total energy consumption of the whole site.
To allocate renewable electricity by proportional consumption follow these steps;
- Obtain the total amount of annual renewable electricity generated on-site;
- Exclude all renewable electricity which has been exported to the grid;
- Determine the respective electricity consumption of all buildings on the whole site (predicted for new builds/measured for existing buildings).
Where consumption data is missing, renewable electricity must not be allocated to the assessed building. In this case, it is assumed that all electricity consumed is sourced from the grid.
Parts of the building not subject to national thermal regulations - KBCN0534
Where you have parts of the assessed building which are not subject to national thermal regulations then these should be omitted from the EPR calculation.
Photovoltaics’ delivered energy - KBCN0841
The BREEAM best practice specification refers to 'on-site electrical generation'. This requires information on the delivered energy from photovoltaic panels, rather than the relevant primary energy.
Please refer to GN25: BREEAM International New Construction 2016 Ene 01 Calculation Methodology for more information.
Shell only – energy demand parameter not available - KBCN0576
In 2016 New Construction (NC) international scheme shell only assessment, energy demand is the required assessment metric for Ene 01. A lot of international assessments are unable to provide the energy demand performance information, and as such, this approach won’t always be possible. Where there is no demand parameter available, follow the same approach as outlined for ‘shell and core’.
Shell only – Installation of building services - KBCN00078
In shell only projects, even where installed system(s) will improve the primary consumption and/or CO2 EPR metrics, only the EPR demand metric should be used for the assessment of Ene 01.
This ensures comparability and consistency between Shell Only assessments.
Shell only – retail glazing not within scope - KBCN0937
Where a retail building envelope is not complete and glazing will be provided by the future tenant/(s), there are two options available:
A 'Green fit-out agreement' (see Definition under this Issue in the technical manual) can be used to ensure that the performance level of the glazing used in the energy model is met in the completed building. This must be accompanied by evidence that the performance of the assumed glazing does not impose overly onerous requirements on future tenants and that it falls within the scope of glazing typically used in retail developments.
Alternatively, the assessment can be based on worst permissible performance under the relevant national building regulations.
In all cases, for shell only assessments, the assessment method detailed in CN1 (for UK New Construction 2014 and International New Construction 2016) and Assessment type specific note 1.3 (for UK New Construction 2018) must be followed.
14 11 2017 Wording amended to clarify the intent
Information correct as of 7thMarch 2021. Please see kb.breeam.com for the latest compliance information.
[KBCN withdrawn] ~ Separate energy models for a single assessment - KBCN00011
This KBCN is now superseded. Please refer to KBCN0216
This KBCN is suspended, pending technical review. When undertaking a similar buildings assessment, compliance must be based on the worst-performing unit for Issue Ene 01 as stated below and in the technical manuals. The area-weighted approach may only be used where multiple buildings falling under the same building type, which require separate energy models are operating as a single entity with a single occupier, such as a school. For building types other than schools, should you consider there is justification to apply the area-weighted approach, please seek advice from BRE by submitting a technical query.
Where the assessment is using the Similar Buildings approach as outlined in GN10, compliance under Ene 01 must be based on the worst performing unit. In the Assessment Scoring & Reporting (S&R) tool the value entered for building floor area can be the combined area of the buildings assessed rather than just the area of the worst case building, as this shouldn’t affect the calculation of the Ene 01 score.
In certain situations, a single assessment with multiple energy models may not follow the Similar Buildings approach as this would unreasonably impact the overall performance. An example of this could be a school assessment with a separate sports hall included in the same assessment.
In these cases, the methodology below applies:
1. For each energy model, input the notional and actual performance figures into the scoring and reporting tool to determine individual EPRs.
2. Manually area-weight each individual EPR to calculate an area-weighted average EPR for the assessment.
3. Use table 25 in the NC 2014 manual, Ene 01, to determine the number of credits awarded.
We will provide an amended S&R tool which will have the relevant cell unlocked to allow the number of credits to be manually inputted. In terms of evidence for QA, we would require screenshots of the S&R EPR outputs for each building and a copy of the area weighting calculation.
Please seek advice from the BRE if in doubt on which methodology applies to your project.
15/02/2018 KBCN Suspended and clarification note added pending review and publication of further guidance.
04/06/2018 KBCN No longer applicable. Reference to GN10 v1.0 added.
31/10/2018 Re-formatted for clarity and reference to GN10 removed from superseded content to avoid confusion.