Energy St@rter
Energy St@rter

Context and challenges

One of the major challenges involved in upgrading the energy performance of existing buildings is reducing energy consumption. Despite all the aid and subsidies available, energy upgrades still pose a problem for multiple occupancy buildings, largely due to a lack of information: how do you find out how much energy your building could save, without paying for an audit and taking a risk? How can you promote an upgrading project to homeowners and tenants without demonstrating its benefits? The Energy St@rter open access energy savings calculator is now available to provide multiple occupancy buildings with this crucial initial estimate.

The solution

Energy St@rter uses key data about the building to automatically generate an appraisal based on a calculation that:

  • identifies building energy losses and indicates the potential energy savings for individual elements of the structure (roof, sub-floors, walls, windows/doors, boiler, energy consumption management, etc.)
  • outlines upgrade scenarios, together with likely costs and levels of difficulty
  • contains instructional information on the concepts of thermally efficient construction

The results are generated by a calculation engine developed in partnership with sustainability design consultants TRIBU. This calculation engine produces reliable results whose accuracy has been demonstrated in a dozen real-life projects.

Energy St@rter does not replace the need for investment in the full energy audit: it provides an initial estimate that offers valuable guidance for occupancy building energy improvements, and is therefore a good starting point from which residents and management companies can discuss upgrade projects.


The solution is designed to trigger multiple occupancy building upgrades that simultaneously reduce the environmental impact of the building. The energy loss reduction costings produced can be easily compared with the energy costs of multiple occupancy buildings to identify and promote the potential long-term financial savings.

Key figures

  • Energy St@rter targets 300,000 multiple occupancy buildings in France, representing a total of 3 million homes
  • Since the website went live last December, it has attracted more than 1,500 hits per month