f Draft Standard for Converting Natural Gas Installations in Multi-occupancy Buildings to Hydrogen

This supplement gives additional requirements and qualifications for the conversion of Natural Gas installations in multi-occupancy buildings to Hydrogen and is only to be used in conjunction with IGEM/G/5 Edition 3. This supplement outlines the principles required for the conversion of existing Natural Gas installations in multi-occupancy buildings to 100% Hydrogen. A conversion to Hydrogen should consider the following options:
a) Repurposing existing installations
b) Renovating existing installations; this may involve, for example, an internal lining being applied to the existing network pipelines.
c) Replacing existing network pipelines with either:
     a. New network pipelines, or
     b. An energy centre.
If, following a risk assessment and cost benefit assessment, none of the above options are considered suitable, the remaining option would be to:
d) Decommission the existing gas installation and install a suitable alternative decarbonisation option (electrification, heat pump, heat network etc.).
This supplement covers the principles required for the repurposing, renovating, and replacement of existing gas installations for Hydrogen service and the decommissioning of existing gas installations.
This supplement provides the principles required to identify buildings and gas installations that are not suitable for repurposing and outlines remedial work that may be required prior to repurposing.
This report was submitted to HSE for their assessment of the safety evidence for 100% hydrogen heating, which can be found at Hydrogen heating: HSE assessment of the safety evidence - GOV.UK.
Queries should be directed to DESNZ: https://www.gov.uk/guidance/contact-desnz.