The Threshing Barn
Cob Barn Conversion Project
In May 2016 we commenced work on a cob barn conversion. The old threshing barn is located rurally, in the heart of Devon’s countryside. When we began work the building was derelict. The tin roof was failing, thereby allowing water to seep into the cob walls, causing more damage with each soaking; if our customer had not rescued the barn, it would have slowly deteriorated until it crumbled completely.
Crumbling exterior of the cob barn prior to restoration
So commenced the project to convert the barn into a traditional living space with a modern twist. The plans allowed for a three bedroom barn conversion of the main barn with a modern extension and an attached thatched linhay.
The end result will encompass a mixture of old and new, combining traditional materials such as cob, and specialist lime rendering techniques. The use of glass and metal will create a modern contemporary feel with careful consideration to the surrounding environment.
With a project such as this one there are many elements involved. We work closely with the customer, architect, and various subcontractors on each part of the project.
Threshing Barn covered by temporary roof
Removal and repair
The first job was to remove the superfluous tin roof. This in itself an easy job; the repair to the damage its inefficacy had caused, more demanding! The cob walls required extensive repairs. We commenced work on the south facing wall and worked our way clockwise around the building, removing any inadequate cob and replacing and rebuilding with cob blocks and earth mortar. Overall the work took around six months to complete.
The beginning of cob repairs to the walls in the main barn
External wall repair using cob blocks
After we completed the main barn’s cob walls, the oak wall plate was fitted. Four oak trusses, hips and purlins then soft wood rafters were put in place, with the insulation installed between. The insulated felt was overlaid and battens made ready for the first slates to be laid.
The slate used for this project was a natural slate called Glendyne. We used a local company, Kilbride Roofing Ltd, for this element of the project.
Oak trusses in the roof of the main barn
Partially laid slate roof
Following the completion of the slate roof, the soffits, fascias, guttering and downpipe details were added.
Slate roof with guttering in place
External Lime rendering
Whilst there was activity on the roof, Earthouse was busy rendering the exterior with a traditional lime render. Lime render allows cob to breathe, allowing moisture to travel in and out of the cob without damaging it. An insulated lime render was used for the first three coats.
External lime render on the barn conversion
The main barn has two windows of note. Both are floor to roof, a height of 4.5 metres each. The window frame is made from Douglas pine, sandwiched between 80mm of oak either side. Aluminium windows will be fitted.
Window being installed in the main barn
Next was the excavation of the interior floors. Then came the laying of insulation (glapor) and the installation of underfloor heating pipe. The main barn has a cut back pumice limecrete screed, not dissimilar to polished concrete, but with different shades of grey and white tones and a matt finish giving a more subtle look.
Limecrete pour finished
A closer look at the limecrete floor in the main barn
The floor in the extension is a polished concrete, which has a beautiful shine when sealed and is more in keeping with the modern element of this part of the building. Again, the concrete is warmed by underfloor heating.
Concrete floor just laid in the extension
The extension itself is a single storey lean-to attached to the north and east elevations of the main barn. The external walls and roof are ultra-modern dark grey crimped zinc. We are seeing so many buildings using crimped zinc now.
Commencement of the contemporary extension
The extension with a crimped zinc roof and cladding and large glass sliding doors
The extension spans two walls of the main barn conversion. It is 50% glass, comprising both doors and windows supplied by Aspect Windows Ltd in Exeter. The photo below shows the far end of the barn conversion, with the extension; these rooms are ensuite bedrooms.
Inside the Threshing Barn
The interior of the barn on completion is large and light. The main living space is vaulted double height, overlooked by a timber mezzanine floor.
Work in progress in the interior of the barn conversion
Upon the mezzanine is the office. Below the mezzanine floor lays a hallway leading to bedroom 3 and the staircase leading up to the floor above. There is also a passageway leading to the ensuite bedrooms 1 and 2 in the extension.
The mezzanine wall in place in the main barn
Upon completion, the mezzanine wall and timber was painted with Farrow & Ball paint in many different shades of grey. The majority of the lighting is from a fantastic shop in Exeter, Amos Lighting, which we highly recommend.
The woodburner and flue was supplied and installed by Woodwarm near Cullompton, who offer a wide range of contemporary and highly economic woodburners.
The almost completed mezzanine in the main barn conversion
No project is ever without its own unique set of complications and whilst at Earthouse we are lucky to work in some beautifully remote locations and we regularly see fantastic wildlife, our barn owl invasion was by far the most spectacular.
Midway through the cob repair process of the walls in the main barn, we came across a nest in a hole in the cob containing two young barn owls. We were first alerted to their presence by the malodourous smell, presumably from the owls eating and digesting numerous small creatures. (We had a good rummage through some of the furry grey pellets they had discarded at a much later date with a vet friend of ours who identified any number of tiny mouse and bird skulls and bones!)
The young owlets were snuggled up in the wall which was in the worst state and without attention this wall could crumble, crushing the birds.
Barn Owl chicks nesting in a cob wall
Barn Owls are a protected species which we were well aware of and we sought immediate advice from The Barn Owl Trust. In order not to disturb the creatures we stopped work until the Barn Owl Trust had visited site and specified where and what we could continue. A temporary owl box was erected closely in the vicinity of their original nest and they quickly took to this, the droppings making their use of it evident.
Many people would be disgruntled by owls stopping work on their site and to a degree it was frustrating. However, the owls enchanted us and the owner, who now has a fantastic extension of a large owl box which the owls began using almost immediately, obviously not concerned by the continuing building works going on around them.
Permanent owl nesting box built into the roof of the house
Another view of the barn owl nesting box at the top of the threshing barn
Before and after – a drastic restoration project!
The final parts of the project are always vital; the construction is obviously key, but these are the bits that the customer living in their home will see. As I write, the site is once again a building site as work commences on The Linhay, so I don’t have the beautiful landscaped photographs of the finished barn quite yet. Below you can see the stark contrast of the barn when we first started working on it, and the newly lime rendered conversion and extension in the wonderful Devon sunshine.
Interior of cob barn prior to restoration
Crumbling exterior of the cob barn prior to restoration
The barn looking stunning in the sunshine with a tree-lined backdrop
View of the barn conversion and extension
The owners spent Christmas in their beautiful barn conversion and we hope to have more interior and exterior photos to show you very soon.
If you would like to know more about the work we do, or to discuss your barn conversion project, please feel free to contact us.
To be continued…The Thatched Linhay