Energy performance and cost analysis for the nZEB retrofit of a typical UK hotel

Abstract It is commonly known that commercial buildings contribute to a large proportion of energy consumption nationally and across Europe. The introduction of ‘nearly zero energy buildings’ (nZEBs) by the Energy Performance Building Directive [Recast] in 2010 has meant that a variety of active measures must be undertaken by the construction industry to define, shape, and meet the standard for both residential and commercial buildings. Hotels are typically ranked amongst the top five energy consumers in the tertiary sector. However, energy saving potential within the hotel industry is also significant. The aim of this study is to present an energy performance analysis and identify the primary energy consumption (PEC) level, post-retrofit, which could represent the cost-optimal level for a UK nZEB-hotel. Thermal Analysis Simulation software (Tas) is used to validate and assess the energy performance of the building pre- and post-retrofit. TasGenOpt is used to select individual EEMs that meet the nZEB targets and create the retrofit scenarios. Finally, building life cycle cost (BLCC) software is used to carry out the global cost calculations. It is found that whilst the nZEB target is technically feasible there is a 30% gap between the nZEB solution and the cost-optimal one. This is significant as it means that the current nZEB standard is not comparable to the best financial solution. The identified cost-optimal PEC level and recommendations provided may be used in the appraisal of other purpose-built UK nZEB hotel retrofits.