March 6, 2020
CIBSE has updated its Technical Memorandum 40: Health and wellbeing in building services (paywall), to reflect what it says are “significant changes in the environmental conditions we are exposed to and advances in our knowledge of how these environments affect our health, comfort and cognitive performance.”
The document claims to address key environmental parameters that impact wellbeing in the design, construction and operation of buildings, specifically: thermal conditions, humidity, air, light, acoustics, electromagnetic fields and water.
This revision updates the original version of TM40, published in 2006. A significant change in the document is the focus on performance outcomes. The revised document summarises existing health-based guidance and regulations and proposes recommended levels for each key environmental parameter. These may then be used as targets in new buildings, fit-outs and refurbishments, or as benchmarks in existing buildings to define priorities and improvement programmes.
This technical memorandum suggests that a useful approach to designing for health and wellbeing is to develop a design strategy for the people in a space and not for the space itself – which may result in a scheme meeting the desired environmental conditions only in the occupied space (rather than in the whole volume).
- For each of these environmental factors, a summary is provided of their health and comfort effects. While a thorough understanding of medical conditions is clearly not within the expertise of engineers (or designers in general), this document aims to provide an overview as background for informed decisions. This leads to recommended performance criteria (e.g. pollutant levels, daylight levels), which may be used as targets in new designs or to reference the performance of existing buildings. Where regulations are lacking, notably on indoor air quality, professionals are advised to refer to internationally recognised health-based guidelines, particularly those from the World Health Organisation. To increase occupant comfort and satisfaction, users should also be provided with a level of choice and control over their environment.
- The scope of ‘health and wellbeing’ is extremely broad, ranging from acute health impacts, through comfort and performance, to ‘joy and happiness’. This TM mostly covers the ‘middle ground’, i.e. best practice design and operation of buildings which can support health, comfort and cognitive performance. Key areas of influence for built environment designers are covered: the quality of the air we breathe and of the water we drink and are in contact with, and the environment around us: light, acoustics, thermal and humidity conditions, and electromagnetic fields. A range of sectors are covered, including new-build non-domestic environments but also homes, refurbishments, and some considerations of neighbourhood and site planning.
- A summary of guidance on design, construction and facilities management is then provided. There are significant opportunities for built-environment professionals to make a positive impact through design approaches that achieve both environmental and health and wellbeing performance, for example in the integration of green infrastructure, the planning of our neighbourhoods, and early building layout decisions for daylighting, ventilation, and acoustic conditions.
- The guidance follows the precautionary principle and source control first as pillars of public health. As for all aspects of building performance, an integrated design approach is required to respond to the user’s needs and balance various constraints and objectives to deliver buildings that are energy efficient, easy to operate, and provide a healthy, comfortable environment with a level of adaptability and resilience.
- This TM is very much aiming for performance in use, not design guidance alone. The benefits of carrying out post-occupancy evaluation and regular monitoring have been established for years, and building performance is expected to be of growing importance due to growing awareness of clients, regulators and the wider public, and the increasing availability of building data to all. Guidance on operations and monitoring is provided to allow building performance assessments, gather lessons learnt, and help us communicate with clients and building occupants; wherever possible, the case studies are based on in-use data.
- Knowledge and products are rapidly evolving. This TM highlights ‘emerging themes’, which are not sections of actual established guidance, but areas still under debate, research, and development, where professionals should follow updates in knowledge, solutions, and products. These are also areas of opportunities for innovation, collaboration with academia, and added value to projects.