NICEIC Domestic Gas Safety On Site Guide 2026 Version 13 – Parts 1 & 2 Digital Ebook

NICEIC Domestic Gas Safety On Site Guide 2026 – Version 13 – Parts 1 & 2

The NICEIC Domestic Gas Safety On Site Guide 2026 – Version 13 is the latest edition of the comprehensive two-part technical reference for engineers working on domestic gas installations.

Published in October 2026, this latest Version 13 edition incorporates important technical updates including changes arising from IGEM/UP/1B Edition 4, which comes into full implementation in October 2026.

The guide is supplied in two parts, providing a substantial reference source covering domestic gas safety, installation, testing, purging, appliances, flues, controls and associated regulatory requirements.

• Part 1 ISBN: 9781838631055
• Part 2 ISBN: 9781838631062
• Edition: Version 13
• Publication Date: October 2026

What's New in the NICEIC Domestic Gas Safety On Site Guide 2026?

The October 2026 Version 13 edition contains a range of technical and editorial updates across Parts 1 and 2. One of the most significant changes is the revision of Chapter 6 covering tightness testing and direct purging to reflect IGEM/UP/1B Edition 4.

Key changes in the 2026 Version 13 edition include:

• IGEM/UP/1B Edition 4 – substantial revisions to tightness testing and direct purging guidance.
• Hydrogen blends up to 20% – the scope of IGEM/UP/1B has been updated to include blends of hydrogen up to 20%.
• Installation volume calculations – total installation volume must be calculated before a tightness test to establish that the installation remains within the scope of IGEM/UP/1B.
• New gas pipework volume table – a new Table 6.5 provides approximate gas pipework volumes for every 5 metres of pipe, including meter and fittings, up to 50 metres.
• Existing installations – revised procedures cover tightness testing where appliances are connected but not isolated.
• Second tightness test requirements – where a pressure drop is observed with appliances included in the test, guidance covers repeating the test with appliances isolated so that the pipework and fittings can be tested separately.
• Direct purging – updated procedures include revised purge volume calculations and clarification of the requirement for a satisfactory tightness test before purging.
• Engineered joists – updated information covering acceptable drilling locations.
• Gas regulator settings – further clarification of testing requirements to BS 6440 and IGEM/G/13.
• Flue terminations – updated information includes definitions for light wells and inner courtyards and additional guidance for existing buildings.
• Building Safety Regulator – additional clarification concerning warm air units in multi-occupancy dwellings and the Building Safety Regulator in England for higher-risk buildings.
• Emergency Service Provider Engineers & Meter Installers – additional information reflecting IGEM/UP/2 Edition 4, including pipe and fitting materials, corrosion protection, tightness testing and purging.

Updated IGEM/UP/1B Edition 4 Tightness Testing Guidance

A particularly important revision in the Domestic Gas Safety On Site Guide Version 13 is the updated Chapter 6 covering tightness testing and direct purging.

The scope of IGEM/UP/1B has been updated to include hydrogen blends of up to 20%, while the tightness testing procedure now requires the total installation volume to be calculated before the test to confirm that the installation falls within the scope of IGEM/UP/1B.

For existing installations where appliances are connected but not isolated, the revised guidance explains the circumstances in which a pressure drop may be permitted and the requirement to undertake a further tightness test with the appliances isolated where applicable.

New Gas Pipework Volume Information

The 2026 guide introduces a new Table 6.5 giving approximate volumes of gas pipework for every 5 metres of pipe, including the meter and fittings, up to a maximum length of 50 metres.

The table provides approximate volumes for meter designations including E6, U6/G4 and U16/G10 and covers pipe materials including copper, steel, stainless steel, pliable CSST and PE.

Updated Direct Purging Guidance

Section 6.5 covering purging installations has been reorganised and updated. Guidance for calculating purge volume has been brought forward and the example calculation revised.

The updated procedure also highlights the requirement for a satisfactory tightness test before undertaking a purge.

Gas Regulations & Regulatory Updates

Version 13 includes an amendment to information concerning the Gas Safety (Management) Regulations 1996 to include biomethane under the 2023 Amendment.

Previous information concerning the Gas Cooking Appliances (Safety) Regulations 1989 has also been replaced with information relating to Regulation 2016/426 and The Gas Appliances (Enforcement) and Miscellaneous Amendments Regulations 2018: Great Britain.

Building Regulations & Building Safety

The updated guide provides further clarification relating to warm air units in multi-occupancy dwellings and the Building Safety Regulator (England) for higher-risk buildings.

Additional information also draws attention to differences between the Building Regulations of the four nations of the UK when considering thermostat height positions above floor level.

Emergency Service Provider Engineers & Meter Installers

Chapter 23 has been expanded with additional information relevant to Emergency Service Provider Engineers and Meter Installers, whose work can encompass both domestic and non-domestic installations.

The revised information reflects IGEM/UP/2 Edition 4 and includes guidance relating to pipe and fitting materials and corrosion protection.

New information has also been introduced covering IGE/UP/1A tightness testing procedures and purging of non-domestic installations.

Who Is the NICEIC Domestic Gas Safety On Site Guide For?

The NICEIC Domestic Gas Safety On Site Guide is a comprehensive practical reference for gas engineers and other professionals working with domestic gas installations.

The October 2026 Version 13 edition is particularly important for engineers requiring current information on IGEM/UP/1B Edition 4 tightness testing and purging procedures and the other regulatory and technical updates incorporated into this edition.

Why Buy the October 2026 Version 13 Edition?

The NICEIC Domestic Gas Safety On Site Guide 2026 Version 13 incorporates important changes to gas safety procedures and technical guidance, including the full implementation of IGEM/UP/1B Edition 4 from October 2026.

For gas engineers using an earlier edition, the revised guidance covering tightness testing, installation volumes, direct purging, hydrogen blends, regulator testing, flue terminations and other regulatory changes makes the latest edition an important up-to-date reference.

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