[Back]

K. Stieldorf:
"Analyse des NutzerInnenverhaltens und der Erfahrungen von BewohnerInnen bestehender Wohn- und Bürobauten mit Pilot- und Demonstrationscharakter";
Talk: Tagung Nutzeraspekte, SIR - Salzburger Institut für Raumordnung und Wohnen, SIR, Alpenstraße 47, 5020 Salzburg (invited); 12-10-2000.

This study focuses on the analysis of occupant behaviour and related aspects like occupant satisfaction in innovative buildings. Furthermore energetic and ecological aspects with regard to the use of these buildings are treated. The results presented in this study are based on data collected from 40 households in 12 buildings with low energy or passive house standard.
This report is divided in three parts: first, the demand for space heating under different user scenarios is calculated with the simulation software EuroWAEBED and comparisons between the calculated requirement and the measured consumption are made. Second, residents´ behaviour and as well as further aspects like occupant satisfaction are discussed based on an analysis of qualitative interviews. Third, a comparison of the investigated buildings focusing on energetical and ecological criteria is performed. In addition to qualitative interviews standardized questionnaires were used in order to collect the necessary data.
The high impact of user behaviour on the demand for space heating can be confirmed by the calculations done in this project. Changes in occupant behaviour like raising room temperature from 20 to 22 °C have a higher relative impact on the demand for space heating for dwellings with excellent thermal quality compared to buildings with lower thermal quality. The demand for space heating calculated on the basis of the sample using conditions is in most cases clearly higher than the demand calculated using standard conditions. This is due to higher room temperature and lower number of people living in a dwelling compared to standard conditions.
The essential motives of the residents for choosing an apartment in the investigated multiple family dwellings or a house in the investigated row houses are advantageous location, affordability, room partitioning, brightness and appealing architectural design. The low energy design of the houses plays a secondary role for the decision, often the inhabitants get to know this fact rather late. Mechanical ventilation systems are criticised fairly frequently in the investigated multiple family dwellings with passive house standard - limited control over the room temperature, dry air in winter and irritation by noise are the most criticized points. The dissatisfaction with the ventilation system can partly be linked to technical problems like insufficient adjustment of the system. Solar passive elements like large south oriented windows or conservatories are well accepted by the residents.
In the investigated single family dwellings the residents are very satisfied with their building, they have a high environmental awareness and in some cases a strong interest in technology.
In the investigated passive houses the residents usually do not abstain from naturally ventilating the rooms in the heating season but they tend do so less often than residents in low energy houses. The mean indoor temperatures are mostly well above 20 °C, in most cases at 22 °C. Surprisingly, feedback measures which show energy consumption in a concise way to the residents are hardly utilized.
The structure of energy consumption changes compared to conventional households - the relative share (in %) of individual mobility and of household devices in total household energy consumption is significantly higher (especially for single family dwellings), the absolute level of consumption for those two energy services is in the same magnitude as in conventional households. CO2-reduction measures are not pursued resolutely - especially for space heating. Especially the observed cases of all-electric households are to criticize in this light.
The conclusions and recommendations from this study are as follows:
Not only the information level of residents should be raised through certain measures (written information, feedback-information, local contact persons) including education (at schools, adult education, in the context of granting subsidies), but there should also be the effort to achieve a higher identification with the dwelling through facilitating a higher degree of participation and a variety of design possibilities in the case of tenants of multiple family dwellings. The experiences of occupants should be taken into account in planning as well as existing standards concerning user behaviour need to be reconsidered. The development of procedures which allow an evaluation of the energy performance of buildings in a standardized manner should be pursued. It is recommended to uphold and develop a diversity of building concepts (in combination with heating concepts) designed for low energy consumption and CO2-neutral heat supply. Future research activities in the sector of household energy consumption should increasingly take into account the interdependency of different energy service sectors (like space heating vs. mobility) and consider the overall lifestyle of occupants and its impact on energy consumption.

In Folge von mehr oder weniger unterschiedlichen Nutzergewohnheiten weicht der in der Planungsphase prognostizierte Heizwärmebedarf oft stark vom tatsächlichen Verbrauch während der Nutzungsphase ab. Insbesondere dann, wenn Bauherr und Nutzer bei Wohn- und Bürogebäuden nicht ident sind, fallen große Unterschiede auf.
Für 12 im Rahmen einer Dokumentation bereits untersuchten Niedrigenergiehäusern (Forschungsprojekt des BMwA) erfolgt einerseits die Berechnung des theoretischen Heizwärmebedarfs mit Hilfe eines validierten dynamischen Berechnungsmodells und andererseits die Erhebung der tatsächlichen Heizenergieverbräuche. Die zu erwartenden Abweichungen dieser Werte werden primär im Hinblick auf das Nutzerverhalten untersucht. Mittels umfassender Interviews der Gebäudenutzer (soziologischer Ansatz) und der Nachmodellierung der Energieverbräuche mit geänderten "Nutzungs"-Programm-Modulen des Berechnungsmodells (technischer Ansatz) werden die aufgetretenen Bedarfs-/ Verbrauchsdifferenzen erklärt. Phänomene im Spannungsfeld zwischen technisch bestimmten (abiotischen) Systemen und durch den Menschen bestimmten (biotischen) Sytemen werden aufgezeigt und Bezüge hergestellt.
Ergebnis der Arbeit wird die umfassende Darstellung des spezifischen Verhaltens und die Analyse der Erfahrungen der Nutzer sein. Daraus erfolgt die Ableitung von Zusammenhängen und die Entwicklung eines Maßnahmenkatalogs - was zu einer problem- und energiebewußten Gebäudenutzung führen soll, ohne daß der Wohn- und Gesundheitswert der Habitate eingeschränkt wird. Solche Maßnahmen sollen primär bessere Information und Motivation sowohl der Nutzer als auch der Investoren, Planer und Bauträger sein. Als weitere Adressaten der Ergebnisse dieser Arbeit bieten sich Behörden, Interessensvertreter und Banken, sowie Technologieproduzenten an. Daher ist die Kommunikation und Kooperation mit all diesen Beteiligten bereits während der Arbeiten wesentlicher Projektinhalt und Voraussetzung für den Erfolg bei der Umsetzung nachhaltiger Entwicklungsziele in der Praxis.
An Hand der Ergebnisse soll ein "Info-Paket" erstellt werden, das als praxisbezogenes "Tool" allen am Baugeschehen Beteiligten via Internet zur Verfügung stehen soll.