[Back]

M. Schuss, M. Fleischhacker, A. Mahdavi:
"Estimated versus actual heating energy use of residential buildings";
Talk: Building Simulation Applications BSA 2022, Bozen / Bolzano; 2022-06-29 - 2022-07-01; in: "Building Simulation Applications BSA 2019", BSA2022 (ed.); bs-press, (2022), Paper ID 149, 8 pages.

Buildings' energy demand plays an important role with
regard to energy conservation objectives as well as
reduction of the emission of greenhouse gases. The wellestablished building energy certificates provide essential
information concerning the thermal quality and the
resulting energy demands of buildings in general. Hence,
related Austrian regulations and standards specify a
demand orientated calculation method based on
construction and material data together with standardized
usage profiles as well as a location related weather data
set. This method is also applied in the case of existing
buildings, which differs from some other European
countries where certificates represent real energy usage
and provide a comparison to similar buildings in terms of
construction period and usage. However, it is not
guaranteed that an energy demand certificate according to
Austrian standards is able to represent the actual energy
use of existing buildings, a circumstance that is typically
referred to as energy performance gap. In this context, we
conducted a comprehensive comparison of real energy
consumption and the certificate-based energy demand
predictions for a number of buildings located in and
around the city of Vienna, Austria. Specifically, 15
residential building complexes with nearly 1400 units
were selected, involving a large variety of buildings'
construction dates and their thermal quality. The
buildings were analyzed in detail based on historic energy
consumption data from 2011 to 2017. The paper provides
an overview of the real energy performance together with
a detailed analysis of the discrepancies between actual
energy use and certificate-based estimations. Generally
speaking, the buildings with a higher energy standard and
lower demand displayed higher discrepancies (expressed
in terms of relative deviations) than older buildings with
higher energy demand.

(no german abstract)
Buildings' energy demand plays an important role with
regard to energy conservation objectives as well as
reduction of the emission of greenhouse gases. The wellestablished building energy certificates provide essential
information concerning the thermal quality and the
resulting energy demands of buildings in general. Hence,
related Austrian regulations and standards specify a
demand orientated calculation method based on
construction and material data together with standardized
usage profiles as well as a location related weather data
set. This method is also applied in the case of existing
buildings, which differs from some other European
countries where certificates represent real energy usage
and provide a comparison to similar buildings in terms of
construction period and usage. However, it is not
guaranteed that an energy demand certificate according to
Austrian standards is able to represent the actual energy
use of existing buildings, a circumstance that is typically
referred to as energy performance gap. In this context, we
conducted a comprehensive comparison of real energy
consumption and the certificate-based energy demand
predictions for a number of buildings located in and
around the city of Vienna, Austria. Specifically, 15
residential building complexes with nearly 1400 units
were selected, involving a large variety of buildings'
construction dates and their thermal quality. The
buildings were analyzed in detail based on historic energy
consumption data from 2011 to 2017. The paper provides
an overview of the real energy performance together with
a detailed analysis of the discrepancies between actual
energy use and certificate-based estimations. Generally
speaking, the buildings with a higher energy standard and
lower demand displayed higher discrepancies (expressed
in terms of relative deviations) than older buildings with
higher energy demand.

https://publik.tuwien.ac.at/files/publik_304502.pdf