One of the most unusual construction projects likely to be completed this year is a replica of a medieval tythe barn near Crewkerne in Somerset.

It is being built by Richard England of Ham & Doulting Stone company, who quarry the Ham limestone being used for the project.

The Great Tythe Barn, as it is being called by businessman Roger Bastable who is having it built as a venue for parties, weddings and corporate conferences at his hoitel and restaurant of Haslebury Mill, is 35m long, 10m wide and more than 10m high. It has a pitch of 50deg on the roof and at the ridge is high enough to accommodate two double decker busses, one on top of the other.

More than 150 tonnes of Ham stone walling have been used to build the barn with quoins using stones up to 900mm on bed and supported by hefty buttresses using constructed using stones 760mm x 810mm x 300mm.

Ham & Doulting say they have not even calculated how much stone has gone into the buttresses, but that they needed to be substantial to support the enormous, oak-framed, slate-tiled roof.

Around the outside of the barn are 400m2 or so of Indian sandstone paving.