Climate change future proofing of buildings—Generation and assessment of building simulation weather files Mark F. Jentsch *, AbuBakr S. Bahaj, Patrick A.B. James Sustainable Energy Research Group, School of Civil Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK 1. Introduction Man-made emissions be it from buildings, business, agriculture or transport are now commonly accepted to be the main cause of the global warming trend which is currently being experienced [1]. Predictions published by the Intergovernmental Panel on Climate Change (IPCC) indicate an increase in global average surface temperature in different scenario ranges of 1.1–2.9 8C to 2.4–6.4 8C from a 1990s baseline towards the end of the 21st century [2]. Across the UK, which is the focus of this study, climate change predictions suggest an average warming per decade varying between 0.1 8C to 0.3 8C for a low emissions scenario and 0.3 8C to 0.5 8C for a high emissions scenario [3]. The summers are expected to become dryer and the winters wetter [3]. In recognition of the strong evidence that climate change is happening, the UK government has declared that climate change is the ‘‘greatest long-term challenge’’ facing the world today [4]. In line with this recognition it has set ambitious targets for the UK’s CO 2 emissions, most notably, a 60% reduction from a 1990 baseline by 2050 [5]. In order to achieve this target, the built environment, which currently accounts for about 45% of the UK’s carbon emissions [6], will need to play a significant role. 2. Implications of climate change for a mature built environment In the more developed regions of the world about 75% of the population live in urban areas [7]. The planning policy overview outlined by the ‘Communities and Local Government’ unit of the UK government states that ‘‘England is one of the most crowded countries in the world with over 90% of its population living in urban areas covering just 8% of the land area’’ [8]. This implies that the effects of climate change need to be addressed specifically in the urban built environment [9]. It is therefore essential to start incorporating the potential impacts of climate change into building design strategies and urban planning regimes now, since consideration at an early stage will help to prevent or at least diminish the occurrence of negative impacts such as flooding or excessive overheating [10]. For example, without taking appro- priate measures, it can be expected that, in the future, increased levels of summer overheating will become established inside naturally ventilated buildings, whereas additional cooling energy will be required in the case of air conditioned buildings [11,12]. Furthermore, as a result of climate change urban heat island Energy and Buildings 40 (2008) 2148–2168 ARTICLE INFO Article history: Received 19 December 2007 Received in revised form 5 May 2008 Accepted 2 June 2008 Keywords: Climate change Weather data Office building Environmental monitoring Thermal simulation Summer overheating ABSTRACT Simulation packages for predicting building performance in terms of energy and comfort are becoming increasingly important in the planning process. However, current industry standard weather files for building simulation are not suited to the assessment of the potential impacts of a changing climate, in particular summer overheating risks. In addition, no bespoke climate change weather files are readily available that can be loaded directly into environmental simulation software. This paper describes the integration of future UK climate scenarios into the widely used Typical Meteorological Year (TMY2) and EnergyPlus/ESP-r Weather (EPW) file formats and demonstrates the importance of climate change analysis through a case study example. The ‘morphing’ methodology published by the Chartered Institution of Building Services Engineers (CIBSE) is utilised as a baseline for transforming current CIBSE Test Reference Years (TRY) and Design Summer Years (DSY) into climate change weather years. A tool is presented that allows generation of TMY2/EPW files from this ‘morphed’ data and addresses the requirements related to solar irradiation, temperature, humidity and daylighting beyond the parameters provided by CIBSE weather years. Simulations of a case study building highlight the potential impact of climate change on future summer overheating hours inside naturally ventilated buildings. ß 2008 Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +44 2380 593941; fax: +44 2380 677519. E-mail address: M.Jentsch@soton.ac.uk (M.F. Jentsch). Contents lists available at ScienceDirect Energy and Buildings journal homepage: www.elsevier.com/locate/enbuild 0378-7788/$ – see front matter ß 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2008.06.005