When doing a barn conversion, people usually choose to retain the charm and essence of the barn and not simply turn it into a regular home, and we share the same feeling.

With this concept in mind, the work done on all the elements of the barn, such as internal elements, doors, windows will also have to comply with any regulations and requirements from the local planning office.

There are several style approaches when it comes to barn conversions, one of them is leaving some of the sections of walls exposed creating an interesting design feature. Or, more recently, customers choose a clearly contrasting mix of new and old materials, bringing character to the whole project.

One of the main issues with any of these approaches is to have the building properly insulated, according to the regulations, which can pose a challenge for brick or stone walls, due to their solid construction with no cavities. With timber barns this aspect will be easier to manage, because the contractors will be able to add more easily the necessary insulation.

The roof

Most like the roof will need repairs during the barn conversion, and this will mean removing the existing covering to both make the repairs and also add the extra insulation needed. Usually it is preferred to keep as much as possible the charm of the original materials, and the irregularities the roof might have gotten over time. The necessary repairs can be made and insulation added without changing the materials and avoiding a perfectly symmetrical roof with modern tiles but no character.
This can also be a requirement for listed building, where the like-for-like materials must be kept, but invariably new materials will also need to be purchased. In this situation, the new material is used as much as possible in less visible places. Original materials may be expensive to procure or unavailable so a carefully thought mix of old and new materials should be used for the roof work.

The end result must be weathertight, and the use of a breathable membrane will provide adequate ventilation, but the charm and character of the old roof should be preserved as much as possible.

The doors and windows

Most of the times, the original window openings are usually kept, at least for the first level, with the possibility of making changes to the second level. When any new openings are inserted in the building’s design, it should follow the pattern of the existing building or other barns in the area. The local planning authority can also determine the style you can use for these. Generally they are simple, robust, with a functional style. Same goes with doors.

When possible, you should salvage and repair any original windows. Use the window styles of other barns in the area as a template in case you can’t salvage the old windows and you need a replacement.

The openings the barn has can be smartly used to provide both ventilation and natural daylight through glazing, which can be fixed or not. Large door entrances that many barns usually have can be fitted with glazed doors and fixed frame sections.
Try to follow the original utilitarian design when it comes to the design of the doors and windows, also when it comes to doors furniture.

ABOVE: Minimal intervention – The gable wall of this barn house, designed by Andrew Shave (01449 678628) has been glazed — much better than rooflights puncturing the charming roof. The extension has been kept simple, too, in a lean-to style.


The roof is the predominant feature of a barn. In most cases it will be necessary to remove the existing roof covering to allow for roof repairs or alterations, and the addition of insulation and membrane to improve weather- and air-tightness.


Insulation can be applied between and beneath the rafters, but where the rafters are made from interesting timbers, and considered worth leaving exposed as an internal feature, it will be necessary to insulate between and over them. This will raise the height of the roof by approximately 100mm.

Part of the charm of a barn conversion can be the irregularity of the roof shape where the original timbers may have bowed, twisted and warped over time. Although evening out the roof will help the roof covering sit flush and weathertight, a completely symmetrical new roof, laid with replacement tiles, can lack character. With care, the roof can be repaired but the undulations carefully maintained.

Dormer windows are not usually appropriate other than where existing, so any new window openings in the roof will be rooflights, and in most instances metal conservation-style rooflights which sit flush with the line of the roof. Too many roof – lights usually looks wrong, and it is best to keep them on the less important elevations.

It may also be possible to introduce a larger area of glazing on minor, less prominent elevations, using a bespoke rooflight system, or by glazing a section of the roof between the existing rafters.

Roof Covering

Vernacular roofing, such as limestone or sandstone tiles, local slate, thatch or local handmade clay tiles, is often an intrinsic part of the character of a barn. It is, therefore, worth salvaging as much as possible of this material and sourcing replacements to make up for any missing material.

Conservationists prefer the use of new material for replacement, as they believe that using salvaged roof coverings encourages the market for stripping other farm buildings – not always legally – which could in turn lead to their demise.

Where new and original roof coverings are mixed together, the original material can be used on the main ‘public’ elevations and the new material on less prominent, minor roof planes, or alternatively on outbuildings. Like-for-like replacement will often be a requirement on a listed building, but for less sensitive situations planners may be more flexible, especially where the material is very expensive or unavailable.

The way the roof is detailed is also an important part of its character, so take photographs and put the roof back as it was, avoiding modern details on verges, valleys and ridge and bargeboards — a breathable roofing membrane will provide adequate ventilation without the need for modern soffit or ridge vents.

ABOVE: Extending in sympathy – Extensions to barn conversions require careful design. Here an oak frame garden room has been added to one end of a stone barn in Carmarthenshire. (Architect David Thomas, 01545 590311).

Windows, Doors and Openings

On the main elevations, window and door openings will often be restricted to those that already exist. On secondary elevations some additional window openings and doorways may be allowed.

If a new opening is to be inserted, sympathetic proportions and detailing should be used, following existing patterns on the building, or other similar farm buildings in the area. In some instances, subject to careful design, new openings could be contemporary in style, though different local planning authorities will take different views on this. For instance, replacing some sections of horizontal timber boarding with clear or translucent Perspex, or glazing part of a gable elevation, in between the timber studs.


Windows and doors need to be simple, robust and functional in style. Setting the windows back into the walls also helps to maintain the shadow lines of the original openings and limits reflections.

Existing openings are often filled only with timber shutters or doors, or sometimes with timber slats, and are often intended to provide ventilation as much as daylight.

If there are any original windows left intact, then it is worth considering salvaging and repairing these, or at least using them as a template for replacements. If there are no surviving windows, look at local farm buildings in the vicinity for clues as to the tradition. Off-the-shelf windows are unlikely to be suitable for size or design.

Narrow ventilation slits are common in agricultural buildings in some areas, and these can be glazed with a fixed doubleglazed unit. Other openings can also be fitted with fixed glazed units, as these may read as unaltered open voids.

Many barns, especially threshing barns, have a large floor-to-eaves cart door entrance at one side, and a smaller exit on the opposite side of the barn. The treatment of this opening – invariably the single biggest opportunity to introduce light to the interior – is one of the major design considerations for such a conversion. A functional design is best, such as glazed doors and fixed sidelights, with a strong vertical emphasis and fixed-frame sections.

Frameless glazing is an option that can be used to fill even the largest opening and – when set well back into the opening – can be unobtrusive.

Barn doors are usually utilitarian, constructed from vertical planks of timber. Proportions are usually sturdy and the outer frame section wide and solid. New doors should follow this pattern with the same finish used for doors and windows. Door furniture and other ironmongery items such as hinges should also be utilitarian.