Building energy efficiency assessment considering IEQ and sustainability certification data for German office buildings

Fahrich, R; Schumann, L; Kremser, L; Schmitt, L and Kriegel, M (2025) Building energy efficiency assessment considering IEQ and sustainability certification data for German office buildings. Building Research & Information, 53(7), pp. 912-928. ISSN 0961-3218

Abstract

Assessing a building’s energy efficiency is a major goal to avoid unnecessary and inefficient energy-consuming renovations. Currently, building energy efficiency is measured primarily by the energy demand of the building. However, the higher energy efficiency of the building is not always aligned with the greater comfort of the occupant, which is the main benefit a building provides. In this study, indoor environmental quality (IEQ) ratings and building energy demand are considered together to evaluate building energy efficiency. It compares the IEQ comfort achieved to the energy demand of the building. An example IEQ index calculation based on certification data of two buildings assessed by a German building sustainability certification system is used. The data include scoring of different IEQ categories and information on energy usage for the buildings. In addition, a survey on IEQ factors was conducted among building users and the results were compared to those based on the certification assessment data. The IEQ rating of the building certification data based on building design and measurement data for the individual factors differed from the subject study results by up to 50%. The overall performance of the considered buildings ranged from 0.13 to 0.16 IEQ-Score per MJ m−2 a−1 for the certification data and survey results.

Item Type: Article
Uncontrolled Keywords: building performance; energy demand; indoor environmental quality; subject study; sustainability certification; thermal comfort
Index terms: building sustainability, renovation, indoor environmental quality, comfort, thermal comfort, building design, energy efficiency, energy demand, office building, certification, building performance, survey
Subjects: quality assurance, architectural design, construction type, occupational health and safety management, environmental health, environmental engineering, administrative processes, renovation and retrofit, sustainability and energy, energy systems, data collection methods
Topics: Sustainability, Engineering Principles, Health and Safety, Quality Management, Construction Technology, Research Practice, Contract Administration, Design Practice
Descriptive scope: 3 PCE

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