A Guide to Converting Barns

Many people start out with a dream of living in the countryside in a house built to their own designs. It is a widely shared aspiration but, for the majority, it will never become anything more than this. Britain has some of the tightest rural planning laws in the world and it is almost impossible nowadays to find a suitable plot in an isolated part of the countryside. The few plots that do come up tend to be replacement dwellings or small infill sites in existing villages.

But there is a chink in the planning armour. Whilst the planners won't countenance building from scratch in the open country, they are keen to see existing rural buildings get a new lease of life. There are thousands of farms dotted around the British countryside. Virtually every one has outbuildings used for storage and a huge number of these are now lying empty and unused. Conservation bodies love these old barns and want to see them survive in some form but there is simply no call for them with modern farming.

Such is the demand for rural building plots that people are willing to pay enormous sums to convert these barns into homes. In doing so, they have created an entirely new form of housing that seems to be unique to Britain. Indeed the very fact that the conversion rather than demolition of redundant buildings is encouraged demonstrates the British obsession with preserving the past.

Converting a barn mixes the best of traditional and modern construction techniques. While it involves restoring centuries old structures often using traditional techniques, the space being created is often far more like an urban loft apartment than a traditional home as served up to us by most developers.

The world of converting redundant buildings is very different to new homebuilding. You have to be prepared to have things imposed on you which you might think are unreasonable and unfair as the planners have a number of ways of making sure that certain rules are adhered to in exchange for the right to create a home in a place you otherwise would not be able to.

Chief amongst these rules is the idea that what you build should continue to look like what was there before - and not in any way resemble a conventional house. This goes for conversions of nearly all redundant buildings with some degree of historic interest; chapels, schools and pubs, for instance. But the bulk of single home conversions are going on in rural barns as these are by far the commonest rural structure available for conversion.

The Rules: The planners have a range of fundamental guidelines for anyone approaching the conversion of a rural building:

• Reuse existing doorways, even if they were designed for carts
• Don't block up existing openings
• No masonry chimneys - stainless steel flues acceptable only if away from the ridge
• As few new windows as possible - and any new windows should be as plain as possible.
• No changes to the roof. Certainly no dormers and preferably no rooflights. If rooflights, preferably on the side no one sees.
• Repair the original material wherever possible. If replaced, use something similar.

What a lot of barn designers end up doing is building in a large glazed screen area where the main barn door once stood. This is often inset into the structure, borrowing a little extra light for the rooms opening off the hallway behind the glazed screen. Although what you end up with doesn't look a bit like a farm building, it does make a very attractive structure. In fact the barn conversion, particularly the timber barn conversion, has rapidly attained iconic status as a fashion item in its own right.

Older barns tend to come in two distinct flavours - timber and stone. Timber predominates in the south and east where they tended to be built for threshing and storing corn. Stone barns are more common in the north and the west - the Scots refer to them as steadings - where they were most often used as cattle sheds. As cattle don't like going up stairs, the stone barns tend to be single storey, while the timber ones are routinely two storey or, more accurately, high enough to accommodate a second storey. There are of course masses of exceptions to this rule and there are also loads of sheds and barns built of other interesting materials such as cob and clay lump.

After a penal brick tax was removed in 1857, a lot of brick barns were built which are equally ripe for conversion. Even steel framed agricultural buildings (you can hardly call them barns) dating from the 1950s get the modern barn conversion treatment, complete with stained weatherboarding. Another example of planning gone mad, perhaps. But why not?

If you see a barn on the market with planning consent for conversion, the chances are that it has already been subject to a thorough examination in order to have obtained that permission. Unlike virgin building plots, you can't obtain outline planning permission on a barn conversion it has to be full planning permission in order to allow the design details to be closely scrutinised by the planners before any approval is granted.

In most areas the planners would ideally like to see redundant farm buildings given over to some commercial use with the hope of creating some rural employment. In fact there are grants of 30% or more available for conversion if you can find a viable business use for the building - this can include farm shops, workshops or even holiday lets.

The trouble is that for a huge number of barns there simply isn't any viable option other than residential conversion for resale (for which there currently seems to be an insatiable demand). However, in order to prove this you have to carry out a business viability survey, assessing likely income from the conversion.

Brian Belton, a surveyor with Durrant & Sons, based in Norfolk, handles a large number of these applications every year and comments: I've yet to find a barn in my patch, the Waveney valley, where the economics of a commercial conversion stack up. You need to show a return of 14-15% before banks will be willing to finance and you only ever seem to get around 78% on the surveys, even with the grant money thrown in.

Only by showing a commercial conversion is unviable can the door to a residential conversion be opened. But before such permission is forthcoming, a detailed structural survey has to be undertaken to see whether the barn is permanent and substantial. In Durrants practice, this involves measuring every timber and inspecting all of the joints.

Most timber barns are in need of a large amount of restoration but very few are unsalvageable. The rule seems to be that if its standing, its salvageable. Typically the timber along the bottom edge - the sole plate - has rotted and sometimes twisted, causing the base of the barn to move outwards, but the sole plate can be replaced and the plinth can be reset. The very fact that a barn has stood for so long is usually a testament to how well it was built in the first place but sometimes decay can be rapid, especially if the roof cover has been removed or blown off. On occasion, conversion has to be carried out very quickly in order to save the building. If it collapses beyond repair, there will be no hope of obtaining permission to rebuild.

This raises another intriguing problem: insurance. Redundant buildings are intrinsically liabilities, not assets. The value is in the development potential, not the structure itself. But the development potential hangs on the structure continuing to at least exist. There is a danger of buying a barn for conversion and losing everything when it burns down or gets blown over before you've started work.

This insurance risk is at least recognised and specialist self-build brokers offer cover for this. But do always bear in mind that most planning consents for barn conversions specifically state that the consent will become invalid if more alterations or repairs are carried out than were agreed - hence the need for a good survey and plenty of shoring up.

Timber Barns: Any conversion needs to start with repairs to the basic the structure. This means securing the walls and repairing the roof. Rarely will any of these buildings have what we now call foundations in any shape or form. Stone or brick plinth walls just tended to spread a little below ground; there were never any attempts to dig down a metre or so onto hard bearing ground. However the barns have stood the test of time so the principle to be observed is that if you dont change any of the loadings, there shouldn't be any need to alter what exists.

Given that the alternative is underpinning and that this tends to cost a minimum of £500/m* (likely to work out at over £20,000 for a barn), then its worth avoiding if possible. So if you wish to build in an upper storey, you have to find a way of keeping the added load of this new floor off the existing walls. The solution usually lies in building a platform inside the barn; this can be achieved with stud walls underneath or, more commonly, using a series of beefy posts which themselves get bedded on new concrete pads.

Then consider the ground floor. The condition of these varies from compacted earth through to level concrete in good condition. Concrete sounds like an advantage but bear in mind that in order to meet the latest U-value requirement for floors you will almost certainly have to put insulation on top of it and consequently you may be losing significant height; often it is better to dig out an existing floor and put in a new one.

There are two additional points to consider here. You don't want to go down so deep that you expose the base of the walls, otherwise you will suddenly find yourself in an underpinning situation exploratory test digs should reveal how far down your walls go under the ground. On the other hand, if you are planning on building an upper deck, you may find that you have to negotiate a tie beam, tying the roof trusses together.

Ideally your finished ground floor level should be at least 4.5m below any tie beams - otherwise you will be having to go on hands and knees to get under them. Although there is no minimum height for rooms or doorways encoded in the current building regs, realistically you need 1.8m clearance on doors to make them comfortable to pass through. If you haven't got a reasonable clearance there may be ways around the problem by gaining access to the different bays from half landings or maybe installing a second staircase. Physically, you may be able to lower the floor a little or you may even be able to jack the entire building up slightly although its wise to keep quiet about this, as the planners might not be too happy!

Actually, it is perfectly acceptable, and even expected, to jack a timber structure up when carrying out restoration work. The procedure is to strip away everything that you dont intend to keep. Often this means reducing the barn to nothing more than a timber skeleton. You then build an internal scaffold cage and place pins under the header plates at the top of the walls which take the weight of the roof. The whole structure then gets lifted gently off the supporting walls at the bottom and this allows you to get to work restoring these walls and replacing the sole plates. If all the bottom joints between the sole plate and the wall studs have rotted, it is standard practice to cut the wall studs shorter and fix a new sole plate (usually green oak) in a slightly higher position than the old one. If other pieces of the original frame are missing or damaged, now is the time that the replacements are made. You will then have to add a couple of courses of brick or stone onto the plinth wall underneath to make up the difference. At this point you would be expected to let the structure down again to sit on the repaired plinth.

From here on in, the timber barn conversion becomes a new build. The roof is insulated, made weathertight and then retiled or thatched, usually to match the original roof covering. The walls will normally get covered in plywood or something similar with insulation added between the timbers in this respect a converted barn must perform to the same standards as a new house.

In timber barns, most people want to see as much as possible of the original roof timbers and therefore the tendency is to find insulation systems which wrap around the exterior and over the roof timbers. The reflective foil insulations, such as Actis, are gaining ground in these markets as they take up so little space. Normally a timber barn will get a new weatherboarded exterior.

Stone Barns: Stone barns pose rather different problems. There will certainly be no jacking up of the structure rather a painstaking repair of what is there. The requirement for good insulation levels means that one face, usually the inside, will have to be covered over. You may need to underpin, especially where new openings are formed and the wall loadings are altered. It very much depends on the ground conditions underneath.

An additional problem is making the structure watertight, something which it was doubtless never designed to be in the first place. A typical stone barn consists of two skins of sorted stone separated by a rubble filled cavity. The existing walls will often be as much as 450mm thick so, on most barns, its impractical to build another skin on the inside therefore you have to work with what is there. It is hard to install a damp proof course and can be difficult to stop rain penetration.

The planners are unlikely to accept a waterproof render being applied to the outside face. The best you can realistically hope to do is to point up the gaps between the stones and accept, perhaps, that you are not living in a new build and that you may have to put up with the odd damp patch.

Cost: Barn conversions cost rather more than new housing on a square metre basis. On a like-for-like basis, the unit area rate works out at between 30% and 50% more than undertaking new builds. Durrants are currently budgeting around 900/m2 for converting timber barns and of course this figure does not include the purchase price.

An upper deck will be slightly cheaper to construct on a square metre basis making two storey barns cheaper than single storey ones. But the saving is not great. Stone barns will tend to be a little more expensive because stone is always time consuming and therefore expensive to work with.

Modern (brick) barns will be cheaper to convert because the structure is usually in better condition. The more exceptional the barn, the more it is likely to cost to convert.

Most barns are not listed unless they happen to be in the grounds (or the curtilage, in planning speak) of a listed farm in which case there may well be extra features to consider, such as thatch. Generally speaking, most barn conversions are undertaken by self-builders. Developers tend to shy away from them because they dont like unpredictability.

Despite the costs and the risks involved, barn conversion opportunities sell quickly. As Brian Belton comments: If somebody wants a home deep in the country, there often isnt that much choice so when barns come onto the market they are currently snapped up, usually within two weeks, up to a maximum of four. And most of the people buying barns are doing it for their own occupation.

Glazing the Cart Door Openings
One of the most important decisions in the conversion of a threshing barn is the treatment of the large cart door openings which typically appear on both sides of the building. Unstained rustic joinery, using chunky, large section timber, with glazing in between, is usually the most successful solution. Various different configurations are possible the best are usually the most minimal. It is always better to avoid bisecting the openings with any new first floor structure. This is usually achieved by leaving this space open to the ridge, possibly spanned by a galleried landing.

Staircases for Barn Conversions
No one style of staircase suits barn conversions, but what must be avoided at all costs is a standard domestic staircase with delicate turned timber spindles nothing will look more incongruous. In a traditional style conversion, large section timber can be used to create a rustic style staircase a derivative of the hay loft ladder. In contemporary style conversions, industrial style steel staircases can work well and are cost effective. Glass, steel and chunky sections of timber are also all appropriate, as is plastered studwork.

Open Plan Living
Barns tend to lend themselves to open plan room arrangements. In fact any other treatment of the floorplan often risks compromising the buildings character, potentially destroying the sense of space and volume that gave it its original appeal. What should be avoided at all costs is the compartmentalisation of the building to create a building that is no different from any suburban home.

Given the planning restrictions on forming new openings, getting light into a barn is usually one of the most difficult aspects of the design, especially in upper storeys. It is therefore essential to make the most of existing openings, and, in particular, the cart door openings in threshing barns. Open plan room arrangements, minimal or glazed balustrading, internal glazing, floor voids and double height spaces will all help borrowed light to spread.

Open Sided Barns
Cart sheds and other open sided barns present both a challenge and opportunity. The opening provides a rare opportunity to bring in light, but it is not easy to get the style of the window frames which must also support the roof right. In a traditional barn, large section timber, ideally the size of the timber studs or roof trusses, creates a sympathetic structure which can be glazed.

The timber posts can be rebated to take double glazed units fitted with weathertight neoprene seals to allow for movement. A separate fillet of timber of the same width as the stud can then be applied over the front to cover the glazing seals and create the appearance of a solid rebated timber frame.

In a contemporary style conversion, a minimal steel frame can be inserted and infilled with toughened floor to ceiling glazing units.

Glazed Ceilings
Light can often be brought in from above on barn conversions. Dormer windows are totally inappropriate, but most planners will consider rooflights, especially the metal conservation variety. Alternatively, the planners may consider a glazed section of the original roof structure. This involves leaving the old timbers in place and glazing in between them. This can be very effective over a double height void designed around the cart door openings in a threshing barn.

Roof Coverings
Often one of the appeals of a barn for conversion is the undulating roofline that is the consequence of years of neglect. Invariably the roofcovering will have to be removed in order that the timbers can be repaired or strengthened, and the structure insulated and made weathertight. In this process it is often tempting to replace the old natural slate, stone or handmade clay tiles with a modern, cheaper and more readily available equivalent. Dont. The result can be to lose a great deal of the buildings character and charm.

Wherever possible, try to keep the original roof covering and make up damaged or missing tiles with replacements sourced from a local salvage yard.

Before stripping the roof, consider whether it is possible to repair the structure and replace broken or missing tiles and then to use a spray-on urethane insulation product that will insulate and weatherproof the roof from inside without the need to strip it.

The roof pitch often gives a clue to the age of the barn; the older the barn, the steeper the pitch. Thatch requires a pitch of more than 50 whereas pantiles and the like work with pitches of 35-40 and when slate arrived in the 19th century the pitch could be dropped to 30.

First Floor Living
Often one of the great appeals of a barn is its timber roof structure. The soaring intersecting beams can have a dramatic, cathedral like quality. In order to make a feature of this many barn converters choose to create a single, open plan, first floor living area with the roof open to the ridge. Bedrooms, which necessarily have lots of dividing walls, are confined to the ground floor. One sacrifice of upside down living is any external dining area off the living area. One solution is to build a rustic style balcony off the main living/dining area, with stairs down to the garden.

Landscaping
Planners will usually be very concerned about the extent and style of any landscaping and fencing around a barn conversion. What they want to avoid is the suburbanisation of the countryside. Ideally, from the public/road side of the barn the building should look unaltered from its original as an agricultural condition. This means careful sighting of drives, turning areas, patios, terraces and, of course, garages which must be open fronted.

Courtyard style arrangements that approximate to a traditional farmyard are the most appropriate, however, this does not have to be traditional in its styling. A minimal but contemporary landscaping scheme can be very effective.

VAT and Barn Conversions
The change of use of an existing building to residential status qualifies the construction work for VAT relief. The rate levied by HM Customs and Excise is currently 0%.

Under C&E Notice 719 VAT refunds for DIY Home Builders and Converters, private individuals can reclaim VAT paid on labour and materials without having to register.
VAT registered builders must invoice for their work and any materials they supply at the reduced rate of 5%. Materials bought directly by the owner will be charged at the standard rate of 17.5%. On completion of the project all receipts that qualify for VAT relief must be submitted together with the relevant forms to the local C&E VAT office which will issue a refund cheque. Only one refund application can be made.

*Estimated price correct as of September 2002

Further reading:

• A Faithful Barn Conversion (Main image)
• An Eco Barn Conversion