The current published framework covers technical requirements, metering and monitoring, network performance and reliability, assessment, improvement and eventual certification. For an existing network, the practical questions are what is installed, what can be measured, what the data shows and what needs attention.
Weather, degree days, calendar and public holiday information, operating periods and occupancy or space data can make comparison meaningful. The source data and method remain visible so analysis can be understood and reviewed.
Government plans to introduce HNTAS from 2027, with requirements phased over time. The final requirements and timetable for existing networks have not yet been published. Use current proposals as preparation guidance while the final scheme develops.