CIBSE is pleased to launch the Domestic Heating Design Guide 2026 (11th edition), providing the latest guidance for designers, installers, and learners working with domestic space heating and hot water systems.
Produced by the CIBSE Domestic Building Services Panel (DBSP), the guide reflects modern design practices, alignment with current regulations, and the evolving climate context for domestic heating and hot water systems.
This updated edition improves technical accuracy, strengthens accountability and introduces clearer guidance on system design, controls, and documentation—while remaining practical and easy to use. A key addition is the System Criteria Document, which allows designers to record and audit all decisions, ensuring professional responsibility and alignment with the Building Safety Act.
Andy Mathews, Chair, CIBSE Domestic Building Services Panel, said: “The new edition of the Domestic Heating Design Guide updates heating design to reflect current regulations, improved technical accuracy, and greater accountability, including alignment with the Building Safety Act.
“It introduces the System Criteria Document to clearly capture design intent and responsibility, updates heat loss and domestic hot water calculations to current standards, adds guidance on controls, and expands coverage of modern system and hydraulic arrangements. Together, these updates support more accurate, efficient, and transparent domestic heating design across the full system lifecycle.”
The guide incorporates the latest CIBSE weather data across 28 zones, updated heat loss and domestic hot water calculations, improved U-value tables, and guidance on low-temperature system design. It also expands coverage of modern hydraulic layouts, fluid dynamics and control strategies, supporting both traditional and low-carbon domestic heating solutions.
Designed for use in new and existing owner-occupied homes, the guide supports a wide range of systems, including low-pressure and low-temperature space heating, open-vented and unvented/pressurised systems, and systems connected to automatically controlled heat sources.
By providing evidence-based design methods, improved system documentation, and practical guidance on commissioning, balancing, and control strategies, the guide helps close the performance gap and ensures systems operate efficiently over their lifetime. It also serves as a core reference for training providers and a reliable technical baseline for accredited installers and designers.
The Domestic Heating Design Guide 2026 is now available for access here
