SmallBudgetBigDreams

Rebuilding a Stone Barn with Hempcrete & Glulam Dutch-Barn Roof – Advice Welcome I’m working on a small rebuild project and would appreciate some technical input from anyone with experience in combining traditional masonry with modern natural materials. The building sits within the old farmyard of a listed property, so I’m aiming to retain the original form and materials as much as possible while introducing a new structure that’s sustainable, breathable, and reversible. Existing Structure Rubble-stone barn with sections of collapsed walling and a corrugated tin roof in poor condition. The goal is to keep or rebuild the stone walls to their original height and footprint, then construct a new glulam timber frame inside to carry all main loads. The existing footprint is roughly 10.8 m × 7 m, with a 7 m × 3.5 m rear extension planned. Proposed Construction Structure: Independent C24 timber frame inside the stone envelope. Walls: Hempcrete cast in situ between the frame members, tight against the existing stonework. Roof: Curved glulam beams forming a Dutch-barn-style arch, finished with new corrugated galvanised sheeting to match the original character. Floor: Limecrete slab over geocell insulation, fully vapour-open. Finishes: Lime plaster internally; repaired stonework and timber cladding externally on rebuilt sections. The design aims for a fully breathable building envelope with no cement or plastic membranes. Points I’d Value Input On Best practice for tying a limecrete slab into old stone footings without trapping moisture. Managing condensation risk under corrugated metal roofs in breathable builds. Experiences with hand-laminated or custom glulam beams for curved roofs. Whether Class R (agricultural to flexible commercial) could apply here, or if full planning is the more realistic route. How best to design for flexibility so the space could convert from light commercial/wellbeing use to small residential use later on. Photos below show the current barn condition and context in the old farmyard, and the SketchUp visuals illustrate the intended rebuild form. Any advice, examples, or lessons from similar hybrid hempcrete–heritage projects would be very welcome.