Integrated design

Natural ventilation is widely applied to new building design as it is an effective passive measure to reach the Net Zero Energy target. However, the lack of modelling guidelines and integrated design procedures that include technology solutions using passive design strategies to exploit climate potential, frustrate building designers who prefer to rely on mechanical systems.

In 2014 the first multi storey residential building planned and constructed to meet the Passivhaus Institute (Darmstadt) criteria was put in operation in Ljubljana, the capital of Slovenia. This massive-structure building is part of the FP7 EE-Highrise project, aiming to demonstrate nearly zero energy building (nZEB) technologies, an integrated design concept, and advanced systems for sustainable construction.

Zero Energy Buildings require airtightness and mechanical ventilation systems to provide air changes and energy saving. These requirements contrast with the principles of natural ventilation. Through a case study located in Modena, Italy, a design strategy is proposed as a solution to integrate natural and mechanical ventilation systems at different times of the year to reduce the energy consumption in a newly designed high-density ZEB. The internal comfort evaluation for the warm season is then verified with a multizone dynamic simulation and a CFD analysis.

Passive cooling by night ventilation is one of the most promising approaches to reduce cooling energy demand of office buildings in moderate climates. However, the effectiveness of this system depends on many parameters.

ID is a design procedure that considers the building as a whole system with the aim of optimizing it throughout the lifecycle. ID can be used to reach high ambitions by developing, discussing and evaluating a scheme using a multidisciplinary team from the initial design phases and it is a proven approach for achieving high-performance buildings with good indoor environment without sacrificing architectural quality or result in excessive costs. Integrated Design support designers in delivering buildings which satisfy occupant’s needs much more than conventionally designed buildings.

Much of the analysis of the potential to save energy and reduce emissions of greenhouse gases in thebuildings sector has focused on the energy savings that can be achieved through incrementalimprovements in the efficiency of individual energy-using devices (motors, fans, pumps, boilers,chillers) but without changing the way in which they are put together as systems. However, muchlarger savings are possible through changes in building systems, and further, these savings can beachieved at much smaller incremental investment cost and sometimes at lower first cost.