With the launch of the draft BREEAM 2018 New Construction manual last month, we will be examining a select number of credit issues in more detail to understand the proposed changes and potential implications of the criteria that could have a significant impact on the design and construction of a project.
We will be providing detailed credit examinations regularly prior to the end of the BRE’s consultation period up to the end of Friday 3rd November 2017, to assist with informing consultation responses to the BRE.
Our first review looks into the ‘Pol 02- Local Air Quality’ credit.
Pol 02- Local Air Quality
This credit has been renamed and replaces the ‘Pol 02- NOx Emissions’ credit within the current BREEAM 2014 New Construction manual. The credit now awards up to two credits, which is down from the three credits available for the equivalent 2014 issue. The key aspect to note is the additional consideration toward minimising the impact on local air quality.
The credit requires all installed combustion plant provided for space heating and domestic hot water to be assessed in accordance with emissions labelling that will be required for all manufacturers in accordance with the upcoming EU Ecodesign Directive. Each combustion system must be assessed against the benchmarks set out within the manual for NOx, particulate matter and VOC emissions, dependant on the combustion technology of the plant and the fuel used.
This issue still considers nitrous oxide emissions (NOx) but it also takes into account VOC and particulate matter emissions from building services systems that could have a major impact on health and wellbeing. Varying thresholds for NOx emissions are now proposed, dependant on the development being within an Air Quality Management Area (AQMA).
Within the proposed 2018 Pol 02 credit issue, BRE now equates heating and hot water systems supplied by grid electricity to have zero emissions for this credit issue, as the focus is toward improving local air quality. This means if grid-electricity based systems, e.g. air source heat pump and electric calorifiers are providing the heating and hot water for the assessed development they will achieve the maximum number of credits for this issue by default. This is in contrast to the 2014 Pol 02 issue, where grid electric based systems were usually not able to gain any of these credits due to the resultant high NOx emissions based on the energy generation mix used. Schemes utilising Combined Heat and Power (CHP) systems as part of an energy efficient services strategy by offsetting their electricity generation with heating and hot water generation may no longer be able to positively support this issue.
Where a number of systems are providing the space heating and hot water for the development, all systems would individually need to be reviewed against the relevant thresholds based on the system type. This differs significantly from the 2014 Pol 02 issue, where the average NOx emission levels could be calculated for a multiple systems service strategy, based on the heat output each system supplied. If multiple systems are likely to be used to improve the building’s energy performance levels, this may offer a greater challenge to achieving the credits for this issue.
Furthermore, the benchmarks specifically for NOx emissions are much lower than the emissions set out within the current Pol 02 issue, especially for developments located in AQMA’s. For example, a traditional gas boiler installed on a site in an AQMA to provide both heating and hot water would need to achieve a NOx level of less than or equal to 24 mg/kWh to gain the maximum no. of credits. If the site was located outside of an AQMA, a NOx level of less than or equal to 27 mg/kWh would need to be achieved. Comparatively the current BREEAM 2014 criteria would require a value of less than or equal to 40 mg/kWh to gain the maximum credits.
There are a number of products on the market that can achieve the proposed thresholds, however it may be more difficult for other system types to achieve the required levels if the technologies are not readily available. BRE do note this, and state that they have provided more challenging benchmarks for some technologies to incentivise the market to improve the performance of their products.