of gardens for stressed patients, families and staff. Behavioural observation and interview methods in post occupancy studies of hospital gardens have shown a faster recovery from stress by nearly all garden users. Limited evidence suggest increased benefits when these gardens contain foliage, flowers, water, pleasant nature sounds, such as birds and water. Related approaches Performance-based building design EBD is closely related to performance-based building design (PBBD) practices. As an approach to design, PBBD tries to create clear statistical relationships between design decisions and satisfaction levels demonstrated by the building systems. Like EBD, PBBD uses research evidence to predict performance related to design decisions. The decision-making process is non-linear, since the building environment is a complex system. Choices cannot be based on cause-and-effect predictions; instead, they depend on variable components and mutual relationships. Technical systems, such as heating, ventilation and air-conditioning, have interrelated design choices and related performance requirements (such as energy use, comfort and use cycles) are variable components. Evidence-based medicine Evidence-based medicine (EBM) is a systematic process of evaluating scientific research which is used as the basis for clinical treatment choices. Sackett, Rosenberg, Gray, Haynes and Richardson argue that "evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients". It is used in the healthcare industry to convince decision-makers to invest the time and money to build better buildings, realizing strategic business advantages as a result. As medicine has become increasingly evidence-based, healthcare design uses EBD to link hospitals' physical environments with healthcare outcomes. Research-informed design Research-informed design (RID) is a less-developed concept that is commonly misunderstood and used synonymously with EBD, although they are different. It can be defined as the process of applying credible research in integration with the project team to inform the environmental design to achieve the project goals. Credible research here, includes qualitative, quantitative, and mixed methods approaches with the highest standards of rigor suitable for their methodology. It is important to understand that the literature for "research-informed" practices comes from education and not from the healthcare disciplines. The process involves application of the outcomes from literature review and empirical investigation to inform design during the design phase, given the constraints; and to share the process and the lessons learnt just like in EDB. Research and accreditation As EBD is supported by research, many healthcare organizations are adopting its principles with the