A look into the ENE04 credit within BREEAM New Construction 2018

This article will look further into the BREEAM ENE04 credit, the credit is labelled as low carbon design and has a maximum of 3 credits for all assessment types (Fully Fitted, Simple Building, Shell & Core, Shell Only).

Aim

The official aim set out within the BREEAM standard is ‘To encourage the adoption of design measures, which reduce building energy consumption and associated carbon emissions and minimise reliance on active building services systems.’

When designing a building, to have the greatest reductions in energy use and carbon emissions, a ‘fabric first’ approach is adopted, this approach aims to reduce the amount of energy used to heat, cool, and light the building. In turn, this also reduces the carbon emissions associated with these activities.

The Ene04 credit’s primary function is to encourage this approach rather than reducing the energy and carbon emissions on-site via the use of renewable technologies only. similar methodologies would be Passivhaus for example.

Passive Design (2 Available Credits)

The first criteria for ENE04 are separated into two sections, equalling one available credit per section.

Section 1 – Passive Design Analysis

This section is linked to the HEA 04 Thermal comfort: Thermal modelling credit. within the HEA04 credit, thermal modelling of the proposed building will be undertaken to ensure that the adequate thermal comfort levels are met for the building type/use. (BB101, TM52, TM59 or similar). The requirements of this credit within ENE 04 are to expand on the findings and design features that have been utilised to achieve the thermal comfort standards.

The BREEAM New Construction 2018 manual highlights the below list of items to be covered as a minimum;

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

The evidence required for this credit will be to show how the above elements have impacted the energy demand and C02 emissions compared to a notional/standard building.

Section 2 – Free Cooling

This credit will also run alongside the thermal modelling that has been undertaken or additional cooling considerations and designs that have been incorporated on site. The aim of this credit is to show that the building is providing an adequate level of cooling NOT supplied by mechanical cooling.

Again, BREEAM New Construction 2018 manual highlights the list of technologies that should be considered:

1. Night time cooling (which could include the use of a high exposed thermal mass)
2. Ground coupled air cooling
3. Displacement ventilation (not linked to any active cooling system)
4. Ground water cooling
5. Surface water cooling
6. Evaporative cooling, direct or indirect
7. Desiccant dehumidification and evaporative cooling, using waste heat
8. Absorption cooling, using waste heat.

Low and Zero Carbon Technologies (1 Credit Available)

The third available credit for ENE04 is gained via the undertaking of a low and zero carbon feasibility study. This is to promote the use of low or zero carbon heating or technologies are part of the services strategy (this could also be linked to ENE01)

As part of the LZC feasibility study, the most appropriate & feasible LZC technology should be selected, this is to be tailored to the site-specific characteristics and display the reductions in carbon emissions and justifications for the selected system

Note: This study is to be undertaken by the end of Concept Design RIBA Stage 2

The New Construction 2018 manual outlines the below minimum requirements to be covered

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 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. If appropriate:
   1. The building is connected to an existing local community CHP system or
   2. the building is connected to an existing source of waste heat or power OR
   3. a building or site CHP system is specified with the potential to export excess heat or power via a local community energy scheme or
   4. a source of waste heat or power is specified with the potential to export excess heat or power via a local community energy scheme
10. Energy storage.

Key points to deciding if these credits are suitable for your site

• Does your development look to achieve an external accreditation i.e. Passivhaus? if so the majority of these credits should be readily available
• Does your development have any planning conditions set on low/zero carbon technologies? if this technology is already part of the project scope to meet conditions of planning. having a feasibility study would be beneficial and will allow for credits to be achieved
• Are you already targetting other ENE credits i.e. ENE01? if so, a large portion of the work may have already been carried out or will be required, therefore having the modelling/consultancy work expanded to incorporate these credits may be worthwhile