Editor: I write in support of Property Week’s Get Set for Net Zero campaign and to provide some observations based on our experience of the issues raised in your recent leader column about the shortcomings of Energy Performance Certificates – or EPCs.

Briefly, a little bit about us to provide context: Ecosted is a developer of sustainable residential and commercial developments in the UK and Europe. The Ecosted product, developed over five years, embraces modern methods of construction and is based on the Passivhaus approach. Annual energy bills for an Ecosted home can be up to 75% less than the national average.

Our credo to is conserve energy and resources and deliver healthy-living homes, and our first scheme will be on site in Q4 this year.

When we built and assessed our demonstration house, we sailed through the assessment around Passivhaus performance but only rated a ‘B’ in the EPC assessment.

Our houses have no gas and only require around 1.5kW of energy to space heat, which we provide by electric heaters. We were told at the time that electric heaters did not score well under the weightings provided for the EPC assessment.

This approach is fundamentally flawed. Here we have a house requiring very little energy to space heat, with solar-thermal hot water and the capacity for photovoltaic panels to make it a net supplier of energy to the grid – and it scores only a ‘B’.

For us, actual performance should be the measure and not a tickbox approach that can be skewed by assumptions built into the modelling. Ratings should be about what we are actually consuming and not what we think we might use.

This is vital. Sustainability and energy policymakers and advisers must be able to measure accurately cause and effect, through real data in real time, to properly inform policy development and its evolution. Without this approach, the UK will not make the advances we need to achieve net zero.

Roger Walker, chief technical officer, Ecosted