CN5 states that it is a minimum requirement to be compliant with the relevant Building Regulations. This only applies to the Parts included in the assessment and to works covered by Approved Document L2B: Conservation of fuel and power in existing buildings other than dwellings: 2010 edition (incorporating 2010, 2011, 2013 and 2016 amendments).
Where Building Regulations apply, and the refurbishment project is subject to building control approval, the approval notice issued by the building control body should be used to show compliance with CN5 at design stage. At post-construction, the completion certificate issued by the building control body should be used to demonstrate compliance with CN5.
Where Building Regulations apply, but the refurbishment project is not subject to the requirements set out in Approved Document L2B, documentary evidence of this must be provided to meet the requirements of CN5. This could be, for example, correspondence from Building Control, reference to relevant statutory guidance or a statement from an appropriate member of the project team.
19 Jun 2025 - Last paragraph updated. 05 Jun 2025 - Wording updated to clarify the intent.
