IGEM/UP/1B Edition 4: What the Latest Changes Mean for Gas Safety Compliance

The publication of Institution of Gas Engineers and Managers IGEM/UP/1B Edition 4 introduces several important updates to tightness testing and direct purging requirements for small gas installations. While the underlying principles of gas safety remain unchanged, the revised standard represents a meaningful procedural shift for organisations responsible for compliance, particularly within the social housing sector.

For contractors, compliance teams, and housing providers, understanding these changes, and implementing them consistently, will be essential.

A Shift Towards Installation Volume-Based Assessment

One of the most significant updates within Edition 4 is the move to an installation volume-based assessment when determining permissible pressure drop on existing Natural Gas installations.

Historically, acceptable pressure loss limits were often interpreted using more generalised approaches. The revised guidance now places greater emphasis on the actual volume of the installation, creating a more tailored and technically accurate assessment process.

In practice, this means engineers and organisations will need to ensure that testing procedures, calculations, and reporting methods align with the updated methodology.

Revised Purge Volume Requirements

Edition 4 also introduces revised requirements relating to purge volumes.

Although purging remains a well-established part of safe commissioning and maintenance activity, the updated guidance provides clearer parameters around how purge volumes should be assessed and managed during works on small installations.

This will likely require organisations to review existing operational procedures and ensure field teams fully understand the updated expectations.

Greater Emphasis on Identifying the Source of Leakage

Another notable change is the clearer requirement to determine whether any permissible leakage originates from connected appliances or from the installation pipework itself.

Where leakage is identified, engineers may now need to isolate appliances and undertake additional re-testing before reaching a final determination. This represents an important clarification within the standard and reinforces the need for robust diagnostic processes during tightness testing.

For many organisations, this could have implications for:

• Engineer training
• Testing times
• Reporting procedures
• Record keeping
• Resident communication processes

Not a Reset — But a Meaningful Change

The introduction of Edition 4 should not be viewed as a wholesale replacement of existing gas safety procedures. However, it is a significant refinement of current practice and one that will require careful interpretation across the sector.

As with any standards update, successful adoption will depend not only on understanding the technical detail, but also on ensuring organisations have:

• Clear internal policies
• Consistent testing methodologies
• Appropriate engineer training
• Accurate reporting frameworks
• Strong quality assurance arrangements

Consistency of interpretation will be particularly important where multiple contractors or compliance providers operate across large housing portfolios.

Preparing for Implementation

For social housing providers and compliance teams, the publication of IGEM/UP/1B Edition 4 presents an opportunity to review current procedures and ensure alignment with the latest industry expectations.

Early engagement, operational review, and practical training will all play an important role in achieving a smooth transition while maintaining the highest standards of gas safety and resident protection.

As the industry adapts to the updated guidance, organisations that invest in clear implementation strategies now will be best placed to demonstrate compliance, improve consistency, and reduce operational risk moving forward.

To read the publication in full, click here.