Energy performance of buildings assessed against BREEAM New Construction 2011

Transcription

1 Energy performance of buildings assessed against BREEAM New Construction 2011 Jose Ortiz & Tom Taylor BRE 17 April 2015 Part of the BRE Trust

2 Introduction Ene 01 credits in BREEAM UK New Construction previously based on CO2 index (EPC rating) Changes to targets in 2010 Building Regulations (Part L) were not uniform across building types and therefore EPC rating no longer represented consistent improvement over regulations for all buildings New methodology devised using weighted average of heating and cooling energy demand, primary energy consumption and CO2 emissions Credits awarded based on performance improvement over notional building using data from Building Regulations compliance calculation.

3 Ene 01 calculation methodology Translator curves for each parameter used to convert relative performance to score. Shape of curve determined through combination of: Building modelling: best practice specification for range of test buildings Policy decision: fix score achieved for meeting best practice performance Parameter scores each multiplied by weighting factor: Proportional to inverse of standard deviation for each parameter from modelling results Reflecting influence of designer over each parameter

4 Paper objectives Review how the market has responded to the new methodology in terms of adopting fabric-first approach Evaluate comparative performance between different building servicing strategies and building types Consider how assessed buildings perform in relation to 2010 Building Regulations requirements and improved 2013 standards

5 Analysis Summary Data from 245 BREEAM New Construction 2011 assessments, including fully fitted and shell only and both design and postconstruction assessments: Education (76) Healthcare (18) Offices (55) Retail (55) Other (41) 25% 20% 15% 10% 5% Average improvement (all buildings) 0% Energy demand Primary energy CO2 emissions

6 Performance against energy demand, primary energy and CO2 emissions parameters

7 Relative performance of different building types Overall: average improvement against CO2 parameter is consistent at around 20% Offices and retail: relatively poor performance in energy demand (retail shows performance below notional building) possibly due to tendency to install large areas of glazing strong performance against primary energy and CO2, suggesting high use of LZC technologies

8 Relative performance of different building types Healthcare: strong performance against energy demand and other parameters. Suggests adoption of fabric first approach Education: relatively poor performance in primary energy compared to other parameters. Suggests poor system efficiencies for other energy end uses (lighting, water heating etc.)

9 Performance of buildings with/without cooling Average number of credits: Cooled: 8.2 Naturally ventilated: 7.3 Naturally ventilated buildings perform better against demand while cooled buildings perform better against other parameters Suggests difficulty in making significant improvements in other parameters in naturally ventilated buildings, therefore requiring a fabric-first approach Difference may also be due to installation of more LZC technologies in cooled buildings (next slide)

10 Other interesting outcomes More detailed data from 50 retail and office assessments ASHP most common heat source in cooled buildings, installed in 50% of all assessed buildings and common at all levels of overall performance (credits) All buildings with GSHPs are in top performance bracket Buildings with standard gas boilers are among the better performing buildings and gas boilers are most common heat source in naturally ventilated buildings Proportion of buildings with solar PV or solar thermal technology installed increases with overall performance (credits) Cooled buildings more likely to incorporate additional solar PV or solar thermal technologies, which may partly explain their higher performance against primary energy and CO2 parameters

11 Performance of BREEAM-assessed buildings compared to mandatory compliance requirements BREEAM-assessed buildings showed a 22% average performance improvement over the TER Of the 245 projects, improvement exceeded: 30% in 60 cases 40% in 23 cases 50% in 12 cases 2 had negative emissions 182 (75%) of the assessed buildings showed at least a 9% improvement over 2010 TER. In effect, this means that 75% of the assessed buildings would be compliant with 2013 regulations

12 Conclusions Better scoring projects seem to be prioritising fabric-first approach Overall trend for improvements against energy demand parameter to be magnified in primary energy and CO2 parameters Lower-scoring projects seem to be prioritising installation of LZC technologies Performance against the CO2 parameter suggests that there is significant scope for buildings to make improvements beyond both the 2010 and 2013 Building Regulations requirements

13 Thank you for listening. Are there any questions? Jose Ortiz E: T: +44 (0)