Planning permission obtained for New Model Barn, a cast hempcrete building at Waltham Place Farm

We were delighted to receive unanimous support from Councillors at the recent RBWM planning meeting for our proposal at Waltham Place Farm.  This exemplar organic and bio-dynamic farm commissioned a loose cluster of field kitchens and cottages on a brownfield site on the edge of the farm – so we decided to bring everything together under one big roof, throw in some extra space for growing and learning, and call the whole caboodle a ‘New Model Barn’.  The Council agreed that the project constitutes Very Special Circumstances in the Green Belt, and the design review panel called it ‘an exemplary holistic exercise’.

The scheme comprises 5 farm worker cottages, 4 field kitchens and a central winter garden for growing vegetables all year round – as well as hosting community events where the sustainability practices of the farm are shared with interested members of the public.  

The project will also extend the practice’s ongoing interest in simple, solid plant-based forms of construction.  In collaboration with Structure Workshop, the building is designed as a timber frame with cast hempcrete for bracing, insulation and enclosure – and the farm will grow some of the hemp.  The building achieves an IStructE rating of A+ for lifetime embodied carbon at Stage 3, and strategies for low operational carbon have been developed with Greengauge. 

Prior to Stage 4, we are currently undertaking some research with The Bartlett UCL on a small Hempstore at the farm, where we are testing methods of achieving airtightness with exposed hempcrete.