Exercises in restoration. Trehilyn was the phased restoration, conversion and expansion of a derelict farm in Pembrokeshire National Park, Wales. Its development was broadcast on the BBC over a five-part series. Trehilyn Cottage was painstakingly rebuilt from stones collected from a 70m radius of the existing building. A vernacular technique of lime washing the stone walls was used to protect the building against the elements. This was in keeping with other white agricultural buildings which are prevalent in that area of Wales. The roof was grouted to soften the edges and recall the landscape beyond. The Mill & Wheelhouse were in a state of dereliction, with only the structure of the Mill and foundations of the old Wheelhouse remaining. The interior of the mill is largely open plan, to retain the feeling of its former life as a historic agricultural space. The adjoining wheelhouse thus contains the principal sleeping quarters, and is clad in standing seam bronze panels, which have weathered to form a rich chocolate patina. This bronze extension rests on large timber beams to protect the archaeology of the existing historic foundations. The Beudy involved the construction of a neighbouring corrugated shed, together with the insertion of a corrugated cherry furniture piece, which sits short of and within the principle room. This loosely choreographs the various uses and building services, without compromising the integrity of the historic building. The roof was carefully reconstructed to exactly replicate the form of the previous historic roof – the slight shifts and imperfections had given the yard its distinct and unique character. The Granary is the final phase of the Trehilyn masterplan. Three adjoining buildings will be connected to form a single dwelling. The robust flooring of the yard has been brought into the interiors to produce a seamless threshold between inside and out, and to preserve their original character. As each building sits on a slightly different level, the steps between them have been notionally expanded to create rooms within rooms, with a softer, more refined timber underfoot.