CN1

Passive design analysis, criteria 1 to 4

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

Note:

For criterion 1, although Hea 04 is not applicable to Shell only assessments, to achieve Ene 04 Passive design credits, compliance with Hea 04 criteria 1, 2 and 3 must be demonstrated. This should be based on a typical layout and equipment specification for the relevant building type. Where Hea 04 is not applicable to the building type and options selected (for example, an industrial building with no office areas), criterion 1 of Ene 04 is not applicable.

LZC feasibility study, criteria 5 to 6

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

Note:

The LZC feasibility study must be completed as part of the shell only design, based on the expected building use and loads specified in the design brief or, where these are not specified, for likely scenarios.

The built form should allow for the future installation of cost effective LZC options and this can be achieved by demonstrating that: sufficient space and clearance for the installation of future LZCs has been considered, the built form is suitably sited, and that mass and orientation are optimised for the future systems.

Refer to Appendix D – Shell and core project assessments for a more detailed description of the shell and core assessment options.

CN3

Passive design analysis - Coverage

As a minimum, the passive design analysis should consider:

1. Site location
2. Site weather
3. Microclimate
4. Building layout
5. Building orientation
6. Building form
7. Building fabric
8. Thermal mass or other fabric thermal storage
9. Building occupancy type
10. Daylighting strategy
11. Ventilation strategy
12. Adaptation to climate change.

CN3.1

Passive design analysis - Approved building energy modelling software

The design team must use a modelling software package that has been approved for assessing this issue, please refer to the Approved Standards and Weightings List (ASWL) to determine whether the modelling software package has already been approved by BRE Global.

If the software package has not been approved the assessor will need to submit an approval request on the “Ene 01 Approval for Energy Software” for before the package can be used for demonstrating compliance with Ene 04.

CN3.2

In circumstances where an existing building element (e.g., a facade) is being retained it is acceptable to incorporate them into the modelling of the 'standard building' baseline, for the purpose of undertaking passive design analysis. All other building elements should be modelled with fabric performance equivalent to that of the local building regulations reference building and without the passive design measures where feasible, i.e., building orientation is likely to be fixed. (KBCN1270)

CN4

LZC feasibility study

The LZC study should cover as a minimum:

1. Energy generated from LZC energy source per year
2. Carbon dioxide savings from LZC energy source per year
3. Life cycle cost of the potential specification, accounting for payback
4. Local planning criteria, including land use and noise
5. Feasibility of exporting heat or electricity or both from the system
6. Identification of any available grants
7. All technologies appropriate to the site and energy demand of the development
8. Reasons for excluding other technologies
9. Where appropriate, connecting the building to an existing low carbon community energy scheme.

CN4.1

LZC feasibility study - Timing

When undertaking a feasibility study later than the Concept Design stage the report must highlight any local LZC energy sources which could not be included in the project due to late consideration and the reason for their omission.

If the feasibility study discounted all local LZC as unfeasible due to the late stage in the project that the study was commissioned, then the credit for the feasibility study must be withheld.

If the feasibility study was commissioned at the Concept Design stage or earlier, and in the unlikely event the study concluded that the specification of any local LZC technology was unfeasible, the LZC credit could still be awarded.

CN4.2

When sufficient information can be provided to justify that LZC energy sources are not feasible for the development, the LCC analysis, for those LZC sources, do not need to be included in the feasibility study. (KBCN0606)

CN4.3

Where a mandatory planning condition exists (e.g., to attach to a district heating scheme), this will clearly affect the number of options available in a feasibility study. In such cases, compliance can still be achieved where evidence of the planning condition restrictions is provided. The feasibility study will still need to be carried out to cover the remaining energy needs of the building (e.g., electrical and lighting load in the case of a district heating scheme). (KBCN0535)

CN4.4

It is acknowledged that for some LZC technologies the level of information available may differ and it may not always be possible to make a detailed like for like comparison across all feasibility considerations.

The feasibility study must make a comparison across all LZC that are feasible for the development (see CN4.2) technologies based on the information that is available so that it can be demonstrated, with a reasonable level of certainty, that the chosen LZCs are the most appropriate of those available. (KBCN0563)

CN4.5

If a project specifies LZCs that have been proposed in the feasibility report 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, this issue 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 must be produced at the final stage - one with the actual interim system installed 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. (KBCN0267)

CN4.6

Where the feasibility study is considering connection to a district heating system and this burns a mixture of fossil and renewable fuels, only the proportion of output generated from eligible renewable fuels (see CN5, recognised LZC energy sources) For instance, a system burning a 25:75 mix of compliant biofuel:fossil fuels, only 25% of heat is considered to be from a LZC technology. As fuel mixes may vary over time, at least one year or more of historical information must be provided to balance out any seasonal variations. Where the system is new or proposed, robust evidence must be provided of the anticipated fuel mix. The fuel mix must be calculated based on the energy content of the input fuels in kWh. (KBCN0885)

CN4.7

One credit can be awarded by default where:

The building is located in a country where the energy supply from the mains grid is highly de-carbonised, due to this supply being generated from renewable sources.

AND

The feasibility study considers the use of energy from the grid in addition to all other fuel types used within the building.

AND

The feasibility study clearly confirms that the introduction of local LZC technologies on site would have an adverse effect on the overall related emissions.

CN4.8

For developments where there is an existing LZC energy source that can supply a compliant percentage of energy to the assessed building, a feasibility study will still have to be carried out to demonstrate that the existing technology is the most appropriate for the assessed building or development. The study should also seek to identify whether any additional LZC energy sources are feasible.

To qualify, the energy from existing LZC energy sources must be additional to the energy that is already being supplied to other buildings or infrastructure entities.

CN5

Technologies eligible to contribute to achieving the requirements of this issue must use energy from the following sources:

• Wind

• Solar radiation (solar thermal and solar photovoltaic)

• Geothermal and hydrothermal energy sources

• Hydropower

• Biomass from waste and biofuels derived from second generation biomass feedstock or waste sources, including landfill gas and sewage treatment gas (see CN5.7 and CN5.8)

• Waste heat (see CN5.4)

• Heat or electricity from waste incineration (see CN5.6)

Note: Heat pumps are now a standard technology and heat from heat pumps is not considered to be an LZC technology for Ene 04.

CN5.1

Where the country of assessment has an independent national certification scheme for installers of local renewable energy systems, these technologies must be certified in accordance with the national scheme.

Where independent accreditation schemes do not exist in the country of assessment, the design team must demonstrate they have investigated the competence of the installer selected to install the LZC technology and that they are confident the installers have the skill and competence to install the technology appropriately.

CN5.2

To be recognised in BREEAM, the LZC technologies must have a direct physical connection to the assessed building.

OR

Where the LZC technology is:

• located on the same site
• is owned and managed by the same organisation 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:

1. Obtain the total amount of annual renewable electricity generated on-site;
2. Exclude all renewable electricity which has been exported to the grid;
3. 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. (KBCN1424)

CN5.3

LZC technologies - Other technology not listed

Other systems may be acceptable as part of a LZC strategy under this issue. Acceptability will be dependent on the nature of the system proposed and the carbon benefits achieved. The BREEAM Assessor must confirm acceptability with BRE Global if in doubt.

CN5.4

LZC technologies - Waste heat from a building-related operational process

Waste heat from an operational process that takes place within the assessed building (or on the assessed site) can be considered as 'low carbon' for the purpose of this BREEAM issue provided that the generation of the heat from the process is integral to the assessed building.

Examples of operational processes and functions include manufacturing processes, high temperature oven or kiln, compressors serving process plant, microbrewery, crematorium, testing and commissioning boilers for training or manufacture, and data centres. It does not include waste heat from IT or server rooms, which could be used as part of conventional heat recovery measures.

CN5.5

LZC technologies - Community and near-site schemes

CN5.6

LZC technologies - Waste incineration

Waste heat from an incineration plant can only be considered as low carbon for the purpose of this BREEAM issue under the following circumstances:

1. All other LZC technologies have been considered and discounted in the feasibility study and; EITHER
2. The local authority or region in which the incineration plant is located is demonstrably meeting its annual waste reuse and recycling targets and waste management policies; OR
3. There is no further capacity for reusing and recycling waste in the local authority or region where the incineration plant is located; OR
4. There is a near-site or on-site facility connected to the building, via a private wire arrangement, which is demonstrably removing reusable and recyclable waste material prior to incineration.

CN5.7

LZC technologies - First generation biomass feedstock

CN5.8

LZC technologies - Second generation biomass feedstock and biofuels from waste streams

BREEAM may recognise systems using biofuels generated from second generation (non-food) feedstocks or biofuels manufactured from biodegradable waste materials, e.g. biogas, waste vegetable oil or locally and sustainably sourced solid biofuels, e.g. woodchip, wood pellets. Further details about the biomass source, the supply chain and the installed plant would be required for review by BRE Global prior to confirmation of acceptability.

The details provided should include:

1. Type, provenance and sustainability of the biomass feedstock
2. Avoidance or minimisation of fossil fuel use in extracting the biofuel
3. Minimising fossil fuel use in transporting the biomass or biofuel
4. Presence of a supply agreement and a robust supply chain
5. Compatibility of the biofuel with the specified boiler or plant and manufacturer's warranty issues.

BREEAM does not define the term 'locally sourced' or specify a minimum supply contract. However, the assessor must determine and demonstrate that these are reasonable for the particular application.

The passive design analysis report.

Evidence confirming the meaningful reduction in the building energy demand.

As design stage AND

BREEAM Assessor’s site inspection report and photographic evidence or

as-built drawings.

Results from a dynamic simulation model demonstrating reductions in CO₂‑eq emissions from the specified low and zero carbon technology.

As per interim design stage.