The use of and interpretation of Regulations, Codes and Standards is important input when developing hydrogen systems and applications. This paper presents the work related to standardisation undertaken by DNV as part of the EU supported project H2SusBuild. During the H2SusBuild project a renewable (solar and wind) based, full scale energy system with components for hydrogen storage, hydrogen production by electrolysis, and hydrogen consumption by fuel cell and burner was built and integrated into an existing office building in Lavrion, Greece. The relevant standards identified and applied, the standardisation gaps identified and the recommendations made for further standardisation activities are presented.