Tackling the Building Energy Performance Gap
When a building is designed there are regulations to say that consideration must be given to the energy performance of that building when it is in use; so calculations are made and a rating is produced, and building regulations are therefore adhered to. Due to the European Commission's push towards reduced emissions and improved energy efficiency and sustainability, such designs and their ratings are looking better and better - on paper.
Once that building is occupied and its users are going about their usual daily activities, the energy performance is generally a very different story. This discrepancy between the predicted and in-use energy performance of a building is commonly known as the Performance Gap. Some reasons for this could be assumptions made at the design stage about the performance of the building components, or lack of communication about (or interest in) the intended energy use. Consumption from small power loads and external lighting are often not accounted for at the design stage, when in fact this type of power would make up a significant proportion of many buildings' total consumption, particularly office buildings and hotels for example.
For those operating building portfolios and for supporting consultants in the energy management profession, these discrepancies between 'as-designed' and 'as-built' can be a source of frustration and in some cases have led to a wholesale distrust of predictive energy consumption models. Bridging this performance gap is an essential part of a transition to a low-carbon building stock, and SMS are collaborating with industry partners and commercial clients to better understand and address this issue.
SMS are leading a project called PERFORMER, which is part funded by the European Commission and involves 14 partners from across Europe (universities, research bodies & building owner occupiers). The intention of this collaboration is to address this performance gap issue through research, design of a technical solution, field-testing and the development of replication strategy that could be widely adopted. We are working on the basis that more accurate and intelligent energy modelling will lead to improved predictions and consequently a much reduced gap between predicted and actual energy performance. The system will act as a decision support tool for building managers by equipping them with detailed energy information and specific recommendations to address anomalies; all of which is currently being tested in 4 pilot buildings.
While the project is ongoing, SMS is intent on making full use of the outputs from PERFORMER to enhance our current service offering to commercial customers. As with any R&D process, it is not only the intended end product that can be utilised, but also the component parts that we have developed along the way. Key learnings from the interim stages have led us to:
- Build smarter, more resilient sub-metering and monitoring networks for commercial clients.
- Introduce enhanced commissioning techniques for new BMS installations based upon the use of big-data analytic tools.
- Undertake critical evaluation of newly constructed buildings and assist clients with revisions to design specifications and specific practices in the operationalisation of buildings.
Each of these projects has been informed by our collaborative research and has provided value to our clients through improved energy efficiency. We hope to be able to further share and commercialise lessons learned from this project in the future and would be interested in discussing this challenge with others in the industry.