A unique pair of front and back extension revitalises end of terrace house in Harpenden, Hertfordshire. Reimagining a redundant garage is a common occurrence for our studio, by reclaiming disused spaces we can make our homes work for modern life. Fellow collaborators Becks and Elliot needed an additional study space for working from home. As the garage adjoins the house at the front of the property it was also an opportunity to reorient and revitalise the front façade. Being an end of terrace property on a prominent intersection privacy was a key driver in our design. We developed a unique solution ‘Stacked walls’ which not only screens the property from prying eyes but also forms the primary timber structure of the extensions. The blackened grid walls are stacked 50 x 50mm Accoya profiled charred timber forming robust structural walls. The grid walls create a veiled quality allowing light and shadow to pass beyond them. Offsetting these grid walls from the house minimises the need for foundation footings. Affectively spanning the timber structure from the house to a new foundation land beam that runs parallel to the property. Drastically reducing the need for concrete consumption and labour. The stacked walls continue our research into sustainable habitable architecture allowing growing space for climbing plants, homes for insects and even ledges for nesting birds. Sustainable new build elements are accompanied by reuse. 60% of the existing garage including the boundary walls and slab below will be reused. By reusing the existing the need for additional concrete is minimised reducing the carbon footprint of the construction. At the rear of the property a lean-to extension is replaced with an angular sunken extension using the same unique stacked wall approach as the front. An overhung roof forms a sheltered yard, formed around Valley cut in the stacked wall which frames the garden vista beyond. Similarly to the side of the extension the wall forms a peaking window into the side access beyond. Internally the timber exposed structure creates a warm feature ceiling interspersed with large top light glazing. A unique linear kitchen interspliced with a feature stacked wall inverted to natural timber to contrast the kitchen. A wrap-around bench forms a family dining nook sunken into the surrounding planting. Floor to ceiling glazing and pivoting door allows the extension to capture the everchanging shadow and light that the walls filter.