Last edited 21 Mar 2018

Main author

Elisa Caton Other Consultant

BREEAM Energy monitoring

Contents

[edit] Aim and benefits

The aim of this credit is to encourage the installation of sub-meters to allow building facilities managers and building users to monitor energy consumption within the building and facilitate identifying end uses with a higher energy demand with the intention to reduce consumption where possible (saving money and CO2 emissions!).

In an ideal world, it would also allow building occupiers to compare meter readings to predicted values to help to identify whether there is faulty equipment or the building is being operated incorrectly. As it stands, the "performance gap" makes this difficult. ENE 01 under BREEAM 2018 aims to start to address this.

[edit] When to consider

RIBA Stages 3-4 (Developed Design-Technical Design)

[edit] Step by step guidance

[edit] Sub-metering of major energy-consuming systems

1. Define all energies relevant for the assessed building (electricity, gas, district heating/cooling, gas, LPG, etc.)

2. Identify all energy-consuming systems present in the building, performing following functions (in BREEAM Manual see Additional information of the Issue) and these to be sub-metered:

CIBSE GIL 65: Tab 13 Size of plant for which separate metering would be reasonable:

Plant Rated input power (kWh)
Boiler installations comprising one or more boilers or CHP plant feeding a common distribution circuit 50
Chiller installations comprising one or more chiller units feeding a common distribution circuit 20
Electric humidifiers 10
Motor control centres providing power to fans and pumps 10
Final electrical distribution boards 50

3. Designer to provide estimated annual energy consumption for each sub-metered part.

4. Calculate whether metering of individual systems covers at least 90 % of each energy/fuel consumption. Consumption of systems/areas without metering can be calculated based on deduction of other sub-metered values or based on operating hours, installed load etc.

Where the sum of sub-metered consumption is less than 90% additional sub-metering is needed. For more guidance see CIBSE guidelines, especially General Information Leaflet 65 (link below) with easily understandable diagrams and schemes.

5. Define the scale of the building for correct metering system selection:

  • GIFA > 1 000 m2: all meters to be connected to the appropriate energy monitoring and management system;
  • GIFA < 1 000 m2: all meters to be either connected to the energy monitoring and management system or with separate accessible energy sub-meters with pulsed or other open protocol communication outputs.

6. Ensure that meters will be easily identifiable to the building users (Property, Facility or Office Manager) through meters labelling and/or BMS designation.

[edit] Sub-metering of high energy load and tenancy areas

1. All meters and their monitoring systems are specified according to the points 5. and 6. above.

2. Identify the future building use and potential tenanted areas.

3. Ensure each tenanted area has sub-metering of significant majority (> 90 %) of the energy supply, where applicable:

4. For single occupancy building metering must be divided per floor and per functional areas. Functional areas types depend on the building usage and is not exhaustive (see the list below).

For small tenant units (GIFA < 250 m2) only one meter for electricity, heating and hot water per unit fulfils the requirement. For larger tenant units (GIFA > 250 m2) metering for both the whole unit and for relevant functional areas is required.

List of functional areas types (in BREEAM Manual see Compliance note – Building type specific):

  1. Office building:

  2. Retail buildings:
  3. Industrial buildings:
  4. Education buildings
    • Kitchens (excluding small staff kitchens and food technology rooms)
    • Office area
    • Computer suites
    • Workshops
    • Lecture halls
    • Conference rooms
    • Drama studios
    • Swimming pools
    • Sports halls
    • Process areas
    • Laboratories
    • High containment suites within laboratories
    • Controlled environment chambers Animal accommodation areas
    • Data centres
    • IT work and study rooms, including IT-equipped library space and any space with provision of more than one computer terminal per 5m².
      Individual sub-metering of standard classrooms or seminar rooms is not required.
  5. Hotel Buildings

[edit] Questions to ask while seeking compliance

  1. What is the building size?
  2. What are the energy sources used on site?
  3. What types of HVAC and Domestic Hot Water systems will be installed?
  4. Will there be any tenancy areas or areas with a particularly high energy load, e.g. catering facilities, cold storage, IT areas or laboratories?

[edit] Tools and resources

Knowledge Base - Ene 02 Energy monitoring (BREEAM NC UK 2014)

Knowledge Base - Ene 02 Energy monitoring (BREEAM RFO UK 2014)

Knowledge Base - Ene 02a Energy monitoring (BREEAM Int. NC 2016)

Sub-metering scheme template (Excel)

[edit] Tips and best practice

  • Double-check that the evidence provided matches up to what you know is included in the building design and is streamlined with other pieces of evidence, e.g. if another piece of evidence shows a café/catering facility on site, make sure this has adequate sub-metering for its scope.
  • Sub-metering, in particular with connection to a BMS/energy monitoring and management system, tends to be something a design team automatically incorporate into the design of a larger building. Where smaller buildings are concerned bear in mind that anything up to 200m2 can have just one meter for electricity and one for heating purposes.
  • Sub-meters aren't particularly expensive in the grand scheme of things.
  • Part L of building regulations requires the 90% part of this credit.
  • Appropriate metering schedule should be incorporated into the building to be able in a future achieve also the BREEAM In-Use energy monitoring issues credits without any additional cost for sub-metering improvement afterwards.

[edit] Typical evidence

[edit] Design Stage Evidence

A schematic/layout for electricity and gas/other energy sources across the development, which should indicate meters and sub-meters on the supply to each relevant energy consuming end-use. If not otherwise stated on the schematic, annotations detailing connectivity to an energy monitoring and management system or, for smaller buildings, provision of meters with an open protocol/pulsed output for connection to a future energy monitoring and management system and confirmation that the sub-meters are identifiable to building users (e.g. labelled).

Confirmation that 90% (under UK New Construction 2014 or equivalent in other schemes) of regulated and unregulated energy consumption can be monitored via sub metering.

[edit] Post Construction Stage Evidence

Worthwhile asking the M&E engineers to check their Design Stage evidence prior to the site visit (just in case there have been any major changes you need to look out for!), an As Built issue of the schematics/layouts would be useful to include as evidence.

Whilst on site, take photographs of meters and sub-meters, showing labelling/connection to the energy monitoring and management system. You could also take photographs of the energy monitoring and management system screen to demonstrate that the energy consuming systems are metered appropriately.

[edit] Applicable Schemes

The guidelines collated in this ISD aim to support sustainable best practice in the topic described. This issue may apply in multiple BREEAM schemes covering different stages in the life of a building, different building types and different year versions. Some content may be generic but scheme nuances should also be taken into account. Refer to the comments below and related articles to this one to understand these nuances. See this document for further guidelines.


BRE Global does not endorse any of the content posted and use of the content will not guarantee the meeting of certification criteria.

--Elisa Caton 12:35, 06 Mar 2018 (BST)

--Sandra Turcaniova 18:30, 20 Dec 2017 (BST)

[edit] Find out more

Part l

Heat meter

TM54: Evaluating Operational Energy Performance of Buildings at the Design Stage

TM39:Building Energy Metering

https://en.wikipedia.org/wiki/Electricity_meter

CIBSE GIL 65 - guidance for energy monitoring in new buildings