Guide A: Environmental Design (8th Edition)
About this book
CIBSE Guide A, "Environmental Design," is the most comprehensive and authoritative reference in the CIBSE stable of publications, covering the full breadth of environmental systems design for buildings. Now in its 8th edition, Guide A serves as the primary technical reference for mechanical and building services engineers designing the heating, cooling, ventilation, daylighting, and acoustic environments of non-domestic buildings in the UK and internationally. The guide is organized around the fundamental environmental variables that building services engineers must understand and control: thermal environment (heat transfer through building fabric, solar radiation, internal heat gains, thermal mass, and their combined effect on space temperatures); moisture (humidity, condensation risk in walls and roofs, and moisture management); air quality and ventilation (outdoor air requirements, contaminant control, and ventilation system design); daylighting and solar control; and acoustic performance (noise criteria, sound insulation, room acoustics).
Each chapter provides the theoretical foundations, design data, calculation methods, and practical guidance needed for professional practice. Particularly detailed are the climate data sections, which provide design reference data for dozens of UK locations covering temperatures, solar radiation, wind speed and direction, and humidity across the full annual cycle. This data underpins both heating and cooling load calculations and natural ventilation assessments.
The thermal comfort chapter summarizes current understanding of the factors governing human thermal comfort, drawing on Fanger's PMV/PPD framework and the adaptive comfort model to set occupant satisfaction targets. This connects directly to the sizing of HVAC systems — the specification of design conditions that systems must maintain determines their size, energy consumption, and cost. The chapters on energy and sustainability in the most recent editions reflect the growing focus on net zero carbon buildings, embodied carbon, and whole-life performance.
Guide A increasingly integrates energy performance alongside comfort and air quality as co-equal design objectives, acknowledging that low-carbon buildings can only be achieved through an integrated understanding of all environmental systems. Guide A is required reading for engineers preparing for CIBSE membership examinations, and it is referenced extensively in UK building regulations, BREEAM, and professional body guidance. It is updated on an approximately ten-year cycle to incorporate new research and changing regulatory requirements.
Sources: CIBSE (cibse.org); CIBSE Guide A 8th Edition official publication; CIBSE Journal technical articles.