The driving force behind the brief for this project was to create a low-energy retreat away from the main house where the clients and their teenage children can work, exercise and relax. The space needed to house flexible, multi-use spaces that connect with the garden and the far-reaching views across the Herefordshire landscape. As part of the project, the clients also wanted to make their site more resilient in energy terms and to move away from a fossil fuel-based heating system towards a cleaner, renewable energy solution. By building with fabric-first principles and making modest upgrades to the fabric of their existing house, the installation of a ground source heat pump and a PV array will make the whole site zero carbon in operation.