The cornerstone of any successful deep domestic retrofit, the foundational principle upon which all other improvements are built, is the fabric first approach. This philosophy prioritises enhancing the performance of the building envelope itself, the very elements that enclose and protect our interior spaces. Rather than solely relying on energy-generating technologies or high-efficiency systems, a fabric first strategy focuses on minimising energy demand in the first instance by creating a highly insulated, airtight and well-ventilated structure. Think of it this way: Before optimising the engine of a car, you would first ensure the chassis is sound and aerodynamic. Similarly, in a deep retrofit, addressing the inherent thermal and constructional weaknesses of a building such as poorly insulated walls, leaky roofs, draughty windows and doors, and thermal bridges is paramount. By significantly reducing heat loss in winter and heat gain in summer, a robust building fabric dramatically lowers the energy required for heating and cooling, leading to substantial and enduring reductions in energy bills and carbon emissions. Embracing a fabric first methodology involves a meticulous assessment of the existing building fabric, identifying areas of weakness and implementing targeted upgrades. This may include the installation of high-performance insulation in walls, roofs and floors, the replacement of inefficient windows and doors with energy-efficient alternatives, and the implementation of rigorous air-sealing measures to eliminate unwanted draughts. By prioritising these fundamental improvements, we lay a solid foundation for a truly energy-efficient and comfortable home, ensuring that any subsequent technologies, such as heat pumps or solar panels, can operate at their optimal efficiency and deliver maximum impact. Join us as we delve into the intricacies and immense potential of deep domestic retrofits, exploring how this profound transformation is not only achievable but essential for a sustainable and thriving future, starting right here in our communities.