(non-residential, plus residential institutions)
For residential buildings, see Ene 02b Energy monitoring.
| Number of credits available | Minimum standards |
|---|---|
|
Building type dependent |
Yes |
Aim
To encourage the installation of energy sub-metering to allow monitoring of operational energy consumption. To allow managers and consultants post-handover to compare actual performance with targets in order to inform ongoing management and reduce any performance gap.
Assessment criteria
This issue is split into two parts:
- Sub-metering by end-use (1 credit)
- Sub-metering by functional or tenanted areas (1 credit)
Please note:
- The first credit is applicable to all building types.
- The second credit is not applicable to preschools, primary schools and residential institutions - long-term stay.
The following is required to demonstrate compliance:
One credit - Sub-metering by end-use
| 1 | Energy meters are installed that allow at least 90% of the estimated annual energy consumption of each fuel or energy supply to be assigned to an end-use category (see Methodology). |
| 2 | The energy metering system is appropriate for the size for the building: |
| 2.a | For buildings with a gross internal area greater than or equal to 1000m², the energy meters are part of an energy monitoring and management system (see Relevant definitions). |
| 2.b | For buildings with a gross internal area less than 1000m², the energy meters are either: |
| 2.b.i | Part of an appropriate energy monitoring and management system. |
| 2.b.ii | Accessible meters with pulsed outputs or other open protocol communication outputs. |
| 3 | Building users can identify the end-use category covered by each meter (for example, through labelling). |
One credit - Sub-metering by functional or tenanted areas
| 4 | Energy meters are installed that allow energy consumption to be assigned to: |
| 4.a | Tenanted areas (see Methodology) |
| 4.b | Relevant functional areas (see Methodology) |
| 5 | The energy metering system is appropriate for the size for the building: |
| 5.a | For buildings with a gross internal area greater than or equal to 1000m², the energy meters are part of an energy monitoring and management system (see Relevant definitions). |
| 5.b | For buildings with a gross internal area less than 1000m², the energy meters are either: |
| 5.b.i | Part of an appropriate energy monitoring and management system. |
| 5.b.ii | Accessible meters with pulsed outputs or other open protocol communication outputs. |
| 6 | Building users can identify the end-use category covered by each meter (for example, through labelling). |
Checklists and tables
Table 28: Examples of relevant functional areas for different building types
| Building type | Relevant functional areas |
|---|---|
|
Office buildings |
1. Office areas, by floor 2. Catering |
| Retail buildings |
1. Sales area 2. Storage and warehouse 3. Cold storage 4. Offices 5. Catering 6. Tenant units |
| Industrial units |
1. Office areas 2. Operational area 3. Ancillary areas (e.g. canteens) |
| Hotel buildings |
1. Office areas 2. Catering (e.g. kitchen, restaurant) 3. Conference suites 4. Swimming pool or leisure facilities 5. Bedrooms, by floor or core (or similar beneficial grouping) |
| Education buildings |
1. Kitchens (excluding small staff kitchens and food technology rooms) 2. Workshops 3. Lecture halls 4. Conference rooms 5. Drama studios 6. Swimming pools 7. Sports halls 8. Process areas 9. Laboratories 10. High containment suites within laboratories 11. Controlled environment chambers 12. Animal accommodation areas 13. IT server rooms 14. IT work and study rooms (including IT-equipped library space and any space with provision of more than one computer terminal per 5m²)
Note: Individual sub-metering of standard classrooms or seminar rooms is not required. |
| Hospitals and other healthcare facilities |
1. Medical physics facilities 2. Rehabilitation when including hydrotherapy pools 3. Central sterile supplies departments (or equivalent) 4. Process areas (e.g. commercial-scale kitchens and laundries) 5. IT server rooms 6. Pharmacy departments 7. Laboratories 8. Tenanted areas (e.g. catering, retail, laundry)
Note: Sub-meters can be provided per floor plate in small healthcare buildings (gross internal floor area less than 1000m²) that have no functional areas with a high energy load. |
| Other buildings | Other types of single occupancy buildings can use the functional areas above as a guide to the type of areas that may require sub-metering. |
|
Notes:
|
|
Compliance notes
| Ref |
Terms |
Description |
|---|---|---|
| Shell and core (non-residential and residential institutions only) | ||
|
CN1 |
Applicable assessment criteria |
Sub-metering by end use, criteria 1 to 3 Shell only: These criteria are not applicable. Shell and core: All criteria relevant to the building type and function apply. Sub-metering of high energy load and tenancy areas, criterion 4 to 6 Shell only: These criteria are not applicable. Shell and core: All criteria relevant to the building type and function apply, subject to the following: Meters must be installed on the energy supply to each separate tenanted unit or floor plate within the assessed development.
Refer to Appendix D – Shell and core project assessments for a more detailed description of the shell and core assessment options. |
| Residential - Partially fitted and fully fitted | ||
|
CN2 |
Applicable assessment criteria - Single and multiple dwellings |
Both options: This issues does not apply to residential dwellings.
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. |
| General | ||
|
CN3 |
Extensions to existing buildings | Where an existing building is being extended and it has existing building services plant and systems that will be common to both the new extension and existing building, the criteria only apply to the extension. In this case, energy services supplying energy-consuming systems from the existing building shall, as a minimum, be metered at the entry points to the extension, e.g. hot water, chilled water, gas and electricity. However, the best practice approach would usually be to ensure that the energy metering covers the entire building. |
| Building type specific | ||
|
CN4 |
Buildings situated on campus developments | The systems for buildings situated on campus developments must be monitored using either an appropriate energy monitoring and management system or another automated control system, e.g. outstations linked to a central computer. The criteria only apply to the assessed building. Where energy services are supplied from an existing building on the campus, they shall be metered at the entry points to the assessed building, e.g. hot water, chilled water, gas and electricity. Provision of a pulsed or other open protocol communication output is not sufficient to award the credit for these building types. |
Methodology
Overall metering strategy
The overall metering strategy should be developed in line with the guidance for new buildings available in CIBSE TM39 Building energy metering1.
As described in the guidance, energy consumption does not necessarily need to be separately monitored if the cost to install the monitoring equipment is expected to exceed the likely benefits and savings achieved.
Sub-metering by end-use
The annual energy consumption of each end-use must be estimated and end-uses that collectively account for 90% of the total energy consumption (for each fuel or energy supply) must be covered by sub-meters.
Where a given end use will clearly account for less than 10% of the total annual energy consumption for the fuel type in question , a simple hand calculation or use of benchmark data to demonstrate this is acceptable.
Where it is unclear whether an end use would account for less than 10% of the annual energy consumption for a given fuel type or not, more detailed calculations should be provided, and energy consumption should be estimated based on actual energy consumption. For example, by using the methods described in CIBSE TM54 Evaluating operational energy performance of buildings at the design stage2. This should use actual operational inputs (rather than those used for building regulations calculations) and weather data for the local area.
The data on water consumption from Wat 01 Water consumption may be used as inputs for evaluating the energy use of domestic hot water.
Typical energy end-use categories include:
- Space heating generation
- Space cooling generation
- Hot water generation
- Mechanical ventilation
- Fans for distributing space heating
- Fans for distributing space cooling
- Pumps for space heating
- Pumps for cooling
- Pumps for hot water
- Commercial scale refrigeration or cold storage
- Internal lighting
- External lighting
- Controls and telecommunications
- IT equipment and small plug in loads
- Internal transport (lifts and escalators)
- Other user defined
End-use categories can be combined for sub-metering purposes (see below).
For a worked a worked example of determining end-use categories to be sub-metered, see General Information Leaflet 65: Metering energy use in new non-domestic buildings 3.
Combining end-use categories
End-use categories may be combined for sub-metering purposes where:
- Separate metering is technically unfeasible.
- The cost to install the monitoring equipment is expected to exceed any likely benefits and savings that could be achieved during the operation of the building.
Some common examples of end uses that can be metered together include:
- Lighting and small power – lighting and small power can be combined where it is not cost effective to sub-meter lighting and small power separately.
- Heating and hot water – space heating and domestic hot water may be combined with a single heat or gas meter where a common plant provides both end-uses (e.g. a boiler) and it is impractical to meter the end uses separately.
- Heating and cooling – space heating and space cooling may be combined when both services are provided by a single piece of equipment (e.g. a reversible heat pump).
- Modular boiler systems -- Modular boiler systems can be monitored as a whole. A modular boiler system consists of a series of boilers that are linked together to meet a variety of heating demands. They are generally composed of several identical boiler units, sometimes stacked, although a mix of condensing and conventional boilers could be used. They operate in increments of capacity, each at around their full capacity and their peak efficiency, so that the overall part load efficiency is greater than it would be for a single boiler.
- Multiple fans – multiple fans may be monitored together (for example, where there are multiple fans within an air handling unit (AHU).
Sub-metering by functional or tenanted areas
Sub-meters must be provided to monitor energy consumption by area when a building has areas with:
- Significantly different energy loads, controls, occupation, or usage patterns.
- Different tenant organisations.
- A single, large, homogenous function that can be split into smaller, discrete, logical areas.
Not every energy end-use category must be sub-metered by area. The sub-metering strategy should prioritise significant energy uses that are controlled by area or vary by area.
For a building with only a single functional area and no tenanted or additional functional areas to be sub-metered, both credits (where applicable to the building type) can be awarded if the first credit has been achieved.
Sub-metering functional areas
All relevant functional areas (see Table 28), and any high energy load areas, must be considered when determining the sub-metering strategy for the building.
In large buildings of single occupancy/tenancy where there is only one homogeneous function (e.g. hotel bedrooms, offices), sub-metering should be provided per floor plate or by core (or other similar beneficial grouping). A sub-metering strategy not based on a by-floor-plate basis, is acceptable provided that:
- It provides an equivalent, or more useful level of detail than sub-metering by floor plate.
- It divides the assessment in a logical manner which provides useful information to building management re: energy use.
- The approach does not conflict with requirements for sub-metering other functional areas.
Sub-metering tenanted areas
For tenanted buildings, meters must be installed on the energy supply to each separate tenanted unit or area. For example, by retail unit (in a retail building) or by floor (in an office building).
Sub-metering large functional or tenanted areas
For a development consisting of one or more larger units (gross internal floor area greater than or equal to 250m²) , sufficient sub-metering to allow for monitoring of the relevant functional areas within the unit must be specified, in addition to metering of the unit as a whole.
Sub-metering small functional or tenanted areas by end-use
Small tenanted office, industrial, or retail units do not need additional sub-metering by end-use beyond:
- Heating
- Electricity
- Hot water (where feasible)
For the purpose of this BREEAM issue, a small unit is defined as a unit with a gross internal floor area less than 250m² .
Evidence
| Criteria | Interim design stage | Final post-construction stage |
|---|---|---|
| All | Relevant section or clauses of the building specification or contract. Design drawings. | BREEAM Assessor’s site inspection report and photographic evidence. |
Additional information
Relevant definitions
- Accessible meters
- Energy meters located in an area of the building that allows for easy access to facilitate regular monitoring and readings by the building occupants or facilities manager. Typically this will be the plant room, main distribution room or control room (where a building energy management system (BEMS) is installed).
- Building users
- The building users are those responsible for monitoring the building's energy consumption (tenants, facility managers, building owner).
- Common areas
- Developments that have several tenant units, particularly large retail developments, may also share common facilities and access that is not owned or controlled by any one individual tenant, but used by all. Common areas are typically managed and maintained by the development's owner, i.e. landlord or their managing agent. Examples of common areas include an atrium, stairwells, main entrance foyers or reception or external areas, e.g. parking.
- Energy meters
-
Energy meters measure the amount of energy used on a circuit where energy is flowing. Primary meters measure the main incoming energy and are used for billing by the utility supplier. They include the principal smart and advanced utility meters to a site for electricity and gas.
Sub-meters are the second tier including heat and steam meters and secondary meters installed to measure consumption by specific items of plant or equipment, or to discrete physical areas, e.g. individual buildings, floors in a multi-storey building, tenanted areas, function areas.
- Energy monitoring and management system
- Examples include Automatic Meter Reading systems (AMR) and Building Energy Management systems (BEMS). Automatic monitoring and targeting (aM&T) is an example of a management tool that includes automatic meter reading and data management.
- Energy supply
- All types of energy supplied to a building area (function area, department, tenancy, or unit) within the boundary of the assessed development. This includes electricity, gas, heat or other forms of energy or fuel that are consumed as a result of the use of, and operations within, each relevant area.
Other information
None.