Building Performance Evaluation

Building Performance Evaluation

There is significant and growing evidence that buildings do not perform as anticipated at their project design stage. Variables that affect building energy performance arise from design, construction, handover and operation. The result is that actual energy performance is often significantly different from its predictions. This is often referred to as the ‘performance gap’ and we provide a service that helps tackle this gap.

Building Performance Evaluation (BPE) is a tested and defined method that can be adopted to measure and monitor building performance before, during and after building projects. In any organisation, energy can't be efficiently managed unless it's monitored effectively and the results are targeted and acted upon. We use the BPE approach to help organisations set up robust energy monitoring systems, provide results to agreed timescales and ensure that identified anomalies are resolved.

We can support you by:

  • Working with you to define an appropriate monitoring and targeting system to meet your needs.
  • Analysing energy profiles in order to help characterise building energy performance, and compare and benchmark performance across sites and against national figures.
  • Developing daily, monthly and annual consumption profiles for individual buildings, with agreed tolerance limits.
  • Setting targets for both total building consumption and individual systems consumption - eg: chilling, heating, small power, lighting.
  • Developing energy reporting requirements for your organisation.

Building Performance Evaluation provides the means of quantifying a building's 'performance gap' between designed and as-built, and provides the key insights into its root causes. The BPE approach is the key to reducing these uncertainties and improving the performance of your building projects. Our experienced team includes staff who were Evaluators, Monitoring Officers and Researchers for the Innovate UK BPE programme, and we were actively involved in developing and implementing the programme.

The Innovate UK BPE programme was an £8 million competition, which involved working with leading industry practitioners to identify where the ‘performance gap’ arises - by evaluating and assessing the post-construction and in-use performance of both domestic and non-domestic buildings. This was done through detailed forensic evaluation, including: fabric in-situ U-value testing, multi-stage air tightness testing, long-term indoor air quality evaluation as well as post-construction reviews, occupant walkthroughs and post-occupancy evaluation.

The programme included a total of 52 new housing projects, of which 54% (28 projects) were led by social housing providers.

Our Technical Team was commissioned to undertake an analysis of the data arising from all these 28 projects, which comprised 83 test dwellings. The ultimate objective of the study was to empower social housing providers to take a lead and become champions in combating the performance gap.

Findings from the study identified:

  • Key success factors (where things worked well and not so well).
  • Practices which resulted in a significant performance gap.
  • The relative impact of specific attributes such as defects and building services on the performance gap.

In particular, the study found that:

  • On average, the fabric U-values exceeded the target set, with nine properties failing to meet the Building Regulations PartL1A (Conservation of fuel and power in new dwellings) backstop.
  • The air tightness of 46% of the BPE test dwellings was below the design intent hitting an average airtightness of 4.4 m3m- 2h-1 @ 50 Pa across all the properties evaluated, against an average design specification of 4.93 m3 h-1 m-2 @ 50 Pa.
  • A high number of commissioning, operation and maintenance-related issues were encountered, in particular where buildings had advanced services equipment configurations in place.
  • Whilst underheating was less of an issue, overheating was more frequently reported. This was not only due to high levels of thermal insulation and airtightness but it was also dictated by window opening behaviour and sub-optimal building design and specification.
  • Overall, BPE emerges as a powerful means of bridging the performance gap and presents sizeable opportunities in terms of transferring the skills gained into future developments.

In short, we can help you by designing and delivering a suitable BPE programme to match your requirements, and examples of our BPE services include:

  • Full Building Performance Evaluation programme design and delivery for domestic and non-domestic projects.
  • Data gathering, monitoring and analysis of the energy performance of buildings and equipment.
  • Design and construction audits.
  • Energy surveys.
  • Building User Surveys (BUS).
  • Building fabric testing including thermographic surveys.
  • TM22 and DomEARM assessments.

Related case studies

Four Housing Group - building performance and post-occupancy evaluation

Sinclair Meadows in South Shields is a development of 21 dwellings built to Level 6 of the Code for Sustainable Homes for Four Housing Group. They were designed to be ‘carbon negative’ and the use of large areas of photovoltaic panels more than offset the energy needed to power and heat the homes. The development is heated by a communal heating system with a biomass boiler.

Suffolk County Council - development of a housing database to target energy efficiency

Suffolk County Council has an ambition to reduce its carbon emissions by 60% by 2025, and recognises that investment in the region’s housing stock will be vital to hitting this target. As an essential first step, the National Energy Foundation was appointed to develop a housing stock database.

Innovate UK - Building Performance Evaluation data meta-analysis

The Building Performance Evaluation (BPE) programme was an £8 million competition funded by Innovate UK. The aim of the programme was to identify where the ‘performance gap’ occurs, and it did so by evaluating and assessing the post-construction and in-use performance of both domestic and non-domestic buildings.

Leading Energy - pre-planning Code for Sustainable Homes Level 6 options tool

We were asked to undertake a study to identify the optimum options to meet Code for Sustainable Homes Level 6 energy targets through fabric optimisation, low-carbon heating and lighting, and low or zero carbon (LZC) technologies.

Energy Saving Trust/Technology Strategy Board - Retrofit for the Future programme

The Retrofit for the Future programme catalysed the retrofit of over 100 homes across the UK with an ambition of achieving an 80% reduction in the in-use CO2 emissions of each property.