Energy & Buildings 183 (2019) 713–726 Contents lists available at ScienceDirect Energy & Buildings journal homepage: www.elsevier.com/locate/enbuild A comprehensive evaluation of a monthly-based energy auditing tool through dynamic simulations, and monitoring in a renovation case study Georgios Dermentzis a,∗ , Fabian Ochs a , Marcus Gustafsson b , Toni Calabrese a , Dietmar Siegele a , Wolfgang Feist a,c , Chiara Dipasquale d , Roberto Fedrizzi d , Chris Bales e a Unit for Energy Efficient Building, University of Innsbruck, Technikerstraße 13, A-6020 Innsbruck, Austria b Environmental Technology and Management, Linköping University, S-581 83 Linköping, Sweden c Passive House Institute, Rheinstr. 44/46, D-64283 Darmstadt, Germany d EURAC Research, Viale Druso 1, 39100 Bolzano, Italy e Energy Technology, Dalarna University, 791 88 Falun, Sweden a r t i c l e i n f o Article history: Received 11 June 2018 Revised 25 October 2018 Accepted 26 November 2018 Available online 1 December 2018 Keywords: Energy audit Renovation PHPP TRNSYS Building simulation Energy conservation a b s t r a c t An energy auditing tool (PHPP) was evaluated against a dynamic simulation tool (TRNSYS) and used for the assessment of energy conservation measures in a demo case study. The comprehensive comparison of useful heating and cooling demands and loads included three building types (single-, multi-family house, and office), three building energy levels (before renovation and after renovation with a heating demand of 45 and 25 kWh/(m²·a)) and seven European climates. Dynamic simulation results proved PHPP (monthly energy balance) to be able to calculate heating de- mand and energy savings with good precision and cooling demand with acceptable precision compared to detailed numerical models (TRNSYS). The average deviation between the tools was 8% for heating and 15% for cooling (considering climates with a relevant cooling load only). The higher the thermal envelope quality was, i.e. in case of good energy standards and in cold climates, the better was the agreement. Fur- thermore, it was confirmed that PHPP slightly overestimates the heating and cooling loads by intention for system design. The renovation design of a real multi-family house was executed using PHPP as energy auditing tool. Several calculation stages were performed for (a) baseline, (b) design phase, and (c) verification with monitoring in order to calculate the corresponding heating demand. The PHPP model was calibrated twice, before and after the renovation. The necessity for tool calibration, especially for the baseline, was highlighted increasing the confidence with respect to a number of boundary conditions. In this study, PHPP was tested as an energy auditing tool aiming to be a versatile and less error-prone alternative to more complex simulation tools, which require much more expert knowledge and training. © 2018 Elsevier B.V. All rights reserved. 1. Introduction and motivation Worldwide, the building sector plays an important role in en- ergy consumption. In the European Union, 40% of the total energy consumption is in the building sector [1]. The largest part of this consumption is due to space heating [2]. Thus, renovation of exist- ing buildings is a key to energy conservation. Energy conservation measures (ECMs) can be assessed with the use of energy auditing tools. ∗ Corresponding author. E-mail address: georgios.dermentzis@uibk.ac.at (G. Dermentzis). Energy audits are the first step towards high energy efficiency by offering support in the planning process of renovated or new buildings. Through the analysis of the building energy consump- tion, an energy audit provides a foundation for the identification of energy conservation opportunities and the choice of appropri- ate ECMs. Although an energy audit can vary regarding its ex- tent, it usually includes the following parts [3]: (a) data collec- tion and review, (b) system survey and monitoring, (c) observation and review of operating practices and (d) data analysis. The im- portance of the energy audit is discussed in ISO 50001 [5]. Studies including energy audits can be found from 1985 [4]. Han et al. [6] used an energy audit aiming to retrofit or replace the HVAC sys- tem for six offices in China. Oliver [7] proposed continuous mon- itoring instead of one-time energy audit aiming to detect possible https://doi.org/10.1016/j.enbuild.2018.11.046 0378-7788/© 2018 Elsevier B.V. All rights reserved.