NHBC Position Statement on: ‘Guidance on evaluation of development proposals on sites where methane and carbon dioxide are present’

In conjunction with our partners, RSK Group Plc, NHBC here confirms our intent to withdraw support and recognition of the joint publication referred to above. This will not be an immediate enactment and will be subject to a transitional arrangement that will expire as of 1^st July 2025. 

Until this time, applications in terms of site assessments and relating to suitability of products that refer to this publication will still be considered by NHBC. 

From 1^st July 2025, they will not, and references should be to more recent standards and guidance that are/will be available and consider the design and detailing of measures that present reasonable mitigation of the potential risk(s). 

NHBC has already provided support to industry in this regard through the NHBC Foundation NF94 publication ‘Hazardous ground gas – an essential guide for housebuilders’, released May 2023, to which readers are initially referred and that is accessible for download.

In support of the above, NHBC will also be embarking on a technical review of its NHBC Standards Chapter 4.1 – Land quality – managing ground conditions for a future standards release.  When and where relevant, updates to or consultations with industry and stakeholders will take place as a vital part of this work.