Last edited 13 Nov 2020

BREEAM LZC technologies


[edit] Definition

Low and zero carbon (LZC) technologies provide a source of energy generation from renewable energy sources or from a low carbon source such as combined heat and power (CHP) or ground source heat pumps (GSHP).

[edit] Aim and benefits

To assess the possibility of using LZC technologies early on in the design process, so as not to limit the possibilities due to fixed site layouts etc.

LZC technologies are one of the steps in the energy heirarchy (after reducing energy demand through passive measures, and that controls and energy use is efficient). Their purpose is to reduce demand on fossil fuels.

Please note, this issue only covers on or near site LZC technologies. Currently, using an 100% renewable electricity supplier does not meet the requirements, as an occupier could change supplier at any point.

This credit builds on the evidence produced as part of the BREEAM Low Carbon Design credits.

While not a specific requirement of BREEAM, it is recommended that the passive design analysis credit is achieved before targeting this credit.

This is line with the Energy Hierarchy which favours making building and systems more energy efficient before incorporating LZC technologies.

This issue offers the following potential benefits to end users and clients:

[edit] When to consider

A feasibility study must be carried out by the completion of the Concept Design stage (RIBA Stage 2 or equivalent) by an energy specialist to establish the most appropriate recognised local (on-site or near-site) low or zero carbon (LZC) energy source(s) for the building/development.

When completed at a later date, an additional element would need to be included within the report to highlight the local LZC energy sources which had been discounted due to the constraints placed on the project by the late consideration, and the reason for omission. If all local LZC is infeasible due to the late stage the study was considered, the credit must be withheld.

If the feasibility study is carried out by RIBA Stage 2 and concludes that the specification of any LZC technologies is unfeasible the LZC credit can be awarded.

[edit] Step by step guidance

An LZC feasibility should be provided, dated at RIBA Stage 2. 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/electricity from the system

6. 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 to the building type, connecting the proposed building to an existing local community CHP system or source of waste heat or power OR specifying a building/site CHP system or source of waste heat or power with the potential to export excess heat or power via a local community energy scheme.

The specified local LZC technologies must be shown to provide a meaningful reduction in regulated carbon dioxide emissions. A meaningful reduction is not specified but as a guide, the installation should contribute to a reduction of at least 5% of overall building energy demand and /or CO2 emissions. The demand reduction with the low and/or zero carbon (LZC) technologies is demonstrated by comparing regulated carbon dioxide (CO2) emissions with LZC technologies to the actual building regulated emissions without LZCs.

The meaningful reduction in regulated carbon dioxide emissions should be assessed against a base case model that includes any passive design or free cooling measures incorporated into the building.

For the specified technology/technologies, the demand reductions are modelled using dynamic simulation modelling. The energy supply used for the base case is mains gas and grid electricity. If mains gas were not available at the site, then oil may be used instead. The base case includes any passive design or free cooling measures adopted for the first two credits. The actual building energy demands are calculated as for the passive design analysis. Then the carbon dioxide emissions factors used for the building regulations calculations are applied.

It must be checked that the feasibility study has been completed by a suitably qualified energy specialist.

Energy specialist: An individual who has acquired substantial expertise or a recognised qualification for undertaking assessments, designs and installations of low or zero carbon solutions in the commercial buildings sector and is not professionally connected to a single low or zero carbon technology or manufacturer.

This role is often undertaken by the Building Services designers as they will be developing the required models as part of demonstrating Part L compliance and Thermal Performance of the building. The individual should be a Member of the Chartered Institute of Building Services Engineers (CIBSE) and/or be an accredited energy assessor.

[edit] Questions to ask while seeking compliance

[edit] Tools and resources

BREEAM 2014 V. 5.0 ENE 4 - Low Carbon Design

Knowledge Base - UK New Construction 2014

[edit] Tips and best practice

Energy specialist: An individual who has acquired substantial expertise or a recognised qualification for undertaking assessments, designs and installations of low or zero carbon solutions in the commercial buildings sector and is not professionally connected to a single low or zero carbon technology or manufacturer.

For shell only developments, in order to achieve criterion 1, thermal modelling can be completed on the basis of a typical notional layout and equipment specification for the particular building type (retail, restaurants, cinema etc.) can be used to demonstrate compliance.

For a shell only project, compliance may be assessed on the built form only i.e. demonstrating that sufficient space and clearance for the installation of future LZCs has been considered, the built form is suitably sited, and that massing and orientation are optimised for the future systems.

[edit] Typical evidence

[edit] Design Stage

1.A copy of the LZC Feasiblity Study, including

2. Confirmation of the demand reduction in CO2 emissions from the specified technology. This should be in the form of 2 x Part L reports (a baseline using gas and grid electric and the actual case). If your project is in London, you may find these labelled as the “Lean” and “Greenscenarios as part of the modelling done to meet The London Plan.

3. Specification or drawings showing technology has been implemented into the design.

[edit] Post Construction Stage

  1. A copy of the BREEAM Assessor’s site inspection report, confirming that LZC technology has been installed
  2. As built drawing/equipment schedule showing specified option
  3. Confirmation that no changes have occurred to the design stage specification, OR, Part L modelling as per design stage assessment for the as built scenario.

[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.

This document was originally created on 7/2/18 in a collaboration of the following BREEAM Professionals: Jane Morning, Cat Clarkson and Azita Dezfouli.

An amendment has been made on 21/02/18 by Tom Blois-Brooke to tie into the BREEAM Low Carbon Design page.

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

--Multiple Author Article 21:59, 21 Apr 2018 (BST)

--Tom Blois-Brooke 16:36, 01 Jul 2019 (BST)

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