Setting sustainability targets for retrofit - What's right for your project?

March 3, 2023

There are many standards, legislation, and methodologies for setting targets, and many options for types and levels of measures to implement, such as external or internal wall insulation, renewable energy generation, ventilation systems, double or triple glazed windows, heat pumps and heat recovery systems...  

Our Usk retrofit project, before work began

The completed Usk retrofit project

It can be difficult to quantify which measures will be the most effective when retrofitting a building, and whether the associated cost and disruption makes it worthwhile. The most important metric is the primary heat demand, which is measured in kWh/M2/year. Here's an overview of some of the most common standards and targets.

 Often there isn’t the budget, or there are other constraints on the building that preclude the work to meet these targets being done. There are often still measures that will be worthwhile undertaking. It is a generally accepted principle in forming a strategy to improve a buildings performance to take a 'Fabric First' approach – that is, improving the thermal performance of the building construction should always be prioritised above improving the systems.  

There’s no one-size-fits-all, but to summarise the approaches: 

• We’d always recommend taking a fabric first approach, when possible. 

• EnerPHit standard for high performance retrofits with the available budget 

• LETI for good performance, or if there are constraints on what can be done to the building.  

• AECB for good performance, or if you want to consider a wider sustainability criteria.