Developing retrofit interventions

  • Summary/introduction
  • Stock analysis
  • Deciding target outcomes
  • Selecting target properties
  • Preliminary design
  • Risk assessment


Developing a plan for the retrofit interventions you will deploy in the project is one of the most complex and most technical tasks in the preparation phase.

It starts with reviewing your housing stock, its type and condition, and leads to a plan for what you want to do with the stock to improve its energy efficiency and its performance.

The goal is to create a specific project targeting a named set of buildings, with a practical series of retrofit measures that will deliver outcomes that meet your strategic objectives, including the needs of any external funders.

Key steps to take

We have broken the task down into five main steps:

  1. Stock analysis – This step is about understanding your housing stock, the type and construction of buildings, their condition and their current levels of energy efficiency so you can create a clear baseline for your project.
  2. Deciding target outcomes – Given the stock and its condition, and the objectives of the organisation, consortium partners and funders, what are our goals? What would be a success for the retrofit project?
  3. Identifying target properties – Given the stock and our target outcomes, which selection of buildings will we include in the retrofit project? This might be a geographic cluster, a particular building type or properties with specific EPC ratings.
  4. Preliminary design – Which combination of energy efficiency and other measures should we apply to our selected properties? How do we create a whole-building plan that is technically deliverable, economically viable, and delivers the target outcomes?
  5. Risk assessment – What could go wrong with our chosen approach? We may fail to deliver the projected energy savings. We may damage the building fabric or have negative effects on residents health and well-being. How can we mitigate these risks in the design or implementation of the project?

The sequence of the steps is not completely linear. It is a more fluid conversation in which each activity influences the others. For example, an initial risk assessment may force you to reconsider your design. Developing a practical design may suggest selecting a different set of properties for the project. The target outcomes you chose may be too ambitious, and you might want to go back to the stock analysis for new inspiration.