The increasing importance of serviced offices as a competing land use in global cities

Once considered a relatively low key land use in central business districts, the number of serviced offices has increased dramatically in recent years. The factors driving the demand for serviced offices have changed, and the suppliers of this service have reacted quickly to meet these needs. This trend has been assisted by the expansion of a select number of multi-national companies that specialise in the provision of serviced offices, available in a flexible range of office types and costs.
This paper considers the reasons behind the rapid growth in the serviced office market, and examines the role of both the user and the provider. Attention is focused on the global marketplace and how these changes have been transformed into the Australian central business districts. The information will be of benefit to property analysts, developers and investors, especially when seeking an alternative use of existing traditional office accommodation.

Evaluation of thermal and visual comfort in offices considering realistic input data and user behaviour in building simulation

Thermal and visual comfort play a very important role regarding the satisfaction of occupants with their working environments. The most effective method to achieve thermal comfort in offices is to reduce cooling loads in order to avoid additional energy-consuming devices for cooling. Building simulation software can be a helpful tool for optimisation, and typically standard values for the influencing parameters are used in order to ensure compliance to norms and regulations.

In practice many of those parameters turn out to be different compared to the simulation assumptions and the reasons may be the chosen room or building related properties as well as the user behaviour influenced by the task and the corporate culture of the company.

This paper investigates exemplary for the climate of Hamburg, Germany and a naturally ventilated typical office room, the optimisation potential of the building- and user-related parameters for thermal comfort, daylighting and view when using realistic input data for building simulation. The study has been conducted with the EnergyPlus based simulation software “Primero-Komfort” [1].

Balancing buildings and occupants - a holistic approach to thermal comfort and greenhouse gas emissions in mixed mode offices

This paper describes a holistic approach to comfort and greenhouse gas emissions in mixed mode offices. It is based on parametric studies for a typical cellular office in the Mediterranean climate of Athens, Greece, using building simulation.

Considered parameters are the influence of different building design, varying occupant behaviour and internal heat loads, as well as of an exceptionally hot summer. Additionally, the performance of a cooling strategy following the comfort limits according to the EN 15251 adaptive model is compared with the common fixed cooling set point 22°C.

The performance of mixed mode offices is evaluated regarding thermal comfort, daylight autonomy and related greenhouse gas emissions. Results indicate strategies to improve sustainability in mixed mode offices in Athens, by balancing the influencing parameters.

On the influence of building design, occupants and heat waves on comfort and greenhouse gas emissions in naturally ventilated offices. A study based on the EN 15251 adaptive thermal comfort model in Athens, Greece

According to the Intergovernmental Panel on Climate Change the buildings sector has the largest mitigation potential for CO2 emissions. Especially in office buildings, where internal heat loads and a relatively high occupant density occur at the same time with solar heat gains, overheating has become a common problem. In Europe the adaptive thermal comfort model according to EN 15251 provides a method to evaluate thermal comfort in naturally ventilated buildings. However, especially in the context of the climate change and the occurrence of heat waves within the last decade, the question arises, how thermal comfort can be maintained without additional cooling, especially in warm climates. In this paper a parametric study for a typical cellular naturally ventilated office room has been conducted, using the building simulation software EnergyPlus. It is based on the Mediterranean climate of Athens, Greece. Adaptive thermal comfort is evaluated according to EN 15251. Variations refer to different building design priorities, and they consider the variability of occupant behaviour and internal heat loads by using an ideal and worst case scenario. The influence of heat waves is considered by comparing measured temperatures for an average and an exceptionally hot year within the last decade. Since the use of building controls for shading affects thermal as well as visual comfort, daylighting and view are evaluated as well. Conclusions are drawn regarding the influence and interaction of building design, occupants and heat waves on comfort and greenhouse gas emissions in naturally ventilated offices, and related optimisation potential.

Context dependency of comfort and energy performance in mixed mode offices

This article investigates the context dependency of comfort and energy performance in mixed-mode offices in the climate of Athens, Greece. It is based on a parametric study using the simulation software EnergyPlus. Context refers to different building design priorities on the real estate market (prestige, low cost and green), occupant behaviour scenarios (ideal and worst case) and cooling strategies (fixed and adaptive set points). Results are evaluated according to energy consumption and related greenhouse gas emissions, daylight autonomy, view and percentage of working time when heating and cooling are operating. The results indicate that a holistic approach to comfort and energy performance evaluation focused on the specific context of a building and its occupants is necessary to develop appropriate optimization strategies. In early design stages, such specific information is not yet available and ideal/worst-case scenarios can indicate the magnitude of influence of occupants compared to building design.

Climate change sensitivity of comfort and energy performance criteria for offices

The climate change scenarios of the Intergovernmental Panel on Climate Change (IPCC) predict a significant increase in temperatures over the next decades. Architecture and building occupants have to respond to this change, but little information is currently available in how far the predicted changes are likely to affect comfort and energy performance in buildings. This study therefore investigates the climate change sensitivity of the following parameters: adaptive thermal comfort according to Ashrae Standard 55 and EN 15251, energy consumption, heating and cooling loads, and length of heating and cooling periods. The study is based on parametric simulations of typical office room configurations in the context of Athens, Greece. They refer to different building design priorities and account for different occupant behaviour by using an ideal and worst case scenario. To evaluate the impact of the climate change, simulations are compared based on a common standard weather data set for Athens, and a generated climate change data set for the IPCC A2 scenario. The results show a significant impact of the climate change on all investigated parameters. They also indicate that in this context the optimisation of comfort and energy performance is likely to be related to finding the best possible balance between building (design) and occupant behaviour and other contextual influences, rather than a straightforward optimisation of separated single parameters.

Impact of climate change on thermal comfort and energy performance in offices - a parametric study

This paper investigates the impact of climate change on comfort and energy performance in offices in relation to the influence of building design and occupants. It focuses on a typical cellular office room in the context of Athens, Greece, as input for a parametric study using the building simulation software EnergyPlus. Three different building design variations are combined with two different occupant scenarios and 4 different weather data sets for IPCC climate change scenario A2.

For naturally ventilated buildings adaptive thermal comfort is evaluated according to ASHRAE Standard 55 and EN 15251. For mixed mode context evaluation is focused on greenhouse gas emissions and peak heating / cooling loads. Results indicate significant impact of the climate change on thermal comfort, and deviations between both comfort models. Comparing climate change, building design and occupant scenarios indicates that building design is the predominant influence on thermal comfort, whereas occupants are the predominant influence on greenhouse gas emissions.

Occupant behaviour simulation for cellular offices in early design stages - Architectural and modelling considerations

Building simulation is most useful and most difficult in early design stages. Most useful since the optimisation potential is large and most difficult because input data are often not available at the level of resolution required for simulation software. The aim of this paper is to addresses this difficulty, by analysing the predominantly qualitative information in early stages of an architectural design process in search for indicators towards quantitative simulation input. The discussion in this paper is focused on cellular offices. Parameters related to occupancy, the use of office equipment, night ventilation, the use of lights and blinds are reviewed based on simulation input requirements, architectural considerations in early design stages and occupant behaviour considerations in operational stages. A worst and ideal case scenario is suggested as a generic approach to model occupant behaviour in early design stages when more detailed information is not available. Without actually predicting specific occupant behaviour, this approach highlights the magnitude of impact that occupants can have on comfort and building energy performance and it matches the level of resolution of available architectural information in early design stages. This can be sufficient for building designers to compare the magnitude of impact of occupants with other parameters in order to inform design decisions. Potential indicators in early design stages towards the ideal or worst case scenario are discussed.