The UK construction industry has long been faced with the problem of the difference between energy consumption of an asset assessed during the design stage versus what is actually consumed during operation. This is referred to as the ‘performance gap’. The energy performance gap in buildings is the difference between the predicted energy performance of a house and its performance as built. The difference accumulates through the design and operation stage and may result in buildings using up more than double their expected energy. The performance gap issues can occur at one or more of the following stages; briefing, design stage, construction, commissioning, handover, in-use post occupancy.
The Built2Spec project aims to deliver the ambitious objective of meeting the EU energy efficiency targets by reducing the energy performance gap for both new buildings and retrofits. This is done through technological advances by development of innovative on-site quality assurance tools.
The energy performance gap needs to be minimised to – a) achieve the 20 per cent energy efficiency target by 2020, b) to reduce energy-related costs for building occupants, c) to ensure the buildings perform as designed. The major causes for this energy performance gap as identified in a recent report by the Zero Carbon Hub are: a) a lack of training in energy performance provided to the construction workforce. This causes a disparity between the expertise available at the design and construction stages; b) new entrants into the on-site construction work force are not being trained in energy performance and hence, lack knowledge of relevant building design; and c) the fact that the Government isn’t leading the way to support initiatives to improve the as-built energy performance.
The Built2Spec project recognises that an integrated approach in which all important aspects of a building, from the design stage through to construction, commissioning and operation are considered can help reduce the performance gap often reported. In order to achieve this, the Built2Spec project will deliver a new set of breakthrough technological advances such as- 3D and imagery tools, building information modelling (BIM), smart building components, energy efficiency quality checks, indoor air quality tools, airtightness test tools with air-pulse checks, thermal imaging tools, accoustic tools; all of which will be connected to a virtual construction management platform (VCMP) supporting the collection and sharing of all project data, from initial design to the delivery.
The efficiency of on-site construction would be greatly improved by improving self-inspection techniques through comprehensive recording of the work on-site. The basic idea is to develop a process that makes it easier for the contractor on-site to achieve higher building standards without the need for an architect to inspect everything, while also allowing all associated parties to collaborate on a common platform to achieve better buildings. However, to achieve the EU energy efficiency targets, the government should give a clear direction showing that they want the construction industry to implement measures to counteract the performance gap and to give the industry a reason to do it. In order to support the industry in providing the required information to quantify the performance gap, the UK government must support the construction industry to create learning loops by funding research and development projects into testing the energy performance of planned houses more accurately. Simultaneously, the stakeholders in the housing industry need to be made suitably aware of the advantages of improving the energy performance by gauging the problems and increased costs due to low energy efficiency designs.
The Built2Spec project consortium involves 20 partners with Nobatek as the overall project co-ordinator. Built2Spec creates an innovation value chain by integrating several universities and industry experts of the construction industry to fulfil its objective of testing new innovative solutions to revolutionize the construction process today. The technical parts of the project where BSRIA’s contribution is involved include - stand-off U-value assessment; i.e. the use of thermal imaging to determine U-Value, low pressure air pulse (air tightness) testing, 3-D model acquisition and imagery techniques, building information modelling (BIM), acoustic testing, and dissemination and communication activities.
The implications of Built2Spec extend beyond just achieving better energy performance; it could result in a more efficient building industry shaping better buildings with higher quality standards in all aspects.