Outbuilding Conversion Questions Checklist

Write down what the walls appear to be built of, whether they are single skin or thicker, and whether the inside face is bare or lined.

The construction of the walls is the single biggest factor in what conversion involves, and it is often quite different from the house itself.

Note whether the outbuilding is attached to the house, joined by a wall, or standing entirely separate, and mark the arrangement on a sketch.

Attachment changes the questions about structure, services and consents, and it is the first thing a professional will want to know.

Photograph every elevation of the building including the sides you never look at, and take a photograph of each internal corner.

The neglected elevation facing a boundary is frequently where the condition problems are, and it is the one owners never photograph.

Photograph anything that looks out of true, such as a wall leaning away from the vertical, a sagging ridge or a door that no longer closes squarely in its frame.

A door or window that has stopped fitting is often the clearest sign an owner can report, and it is more informative than a general remark about cracks.

Do not draw a conclusion from any of this. Whether movement in an outbuilding matters is for a qualified structural professional to establish on site.

Note when the outbuilding was built as far as you know, what it was originally for, and where that information came from.

Original purpose explains a great deal about how a building was constructed and what it was never expected to do.

Note whether any wall of the outbuilding sits on or very close to a boundary, and whether any part of it oversails a neighbouring plot.

Buildings close to boundaries raise both legal and practical questions that are much easier to handle before any design work starts.

Rights and obligations where a building meets a boundary are legal matters to confirm with a qualified adviser and, where relevant, your local authority.

Write down what the floor is made of, whether it is cracked, dusty, stained or patched, and whether it is level across the building.

Floor condition drives an enormous part of what conversion involves, and it is visible without opening anything up.

Note how the floor level compares with the ground immediately outside, and whether the ground outside sits above or below it.

A slab sitting low against the surrounding ground is a common feature of buildings put up for vehicles, and it is worth noting before a floor finish is imagined.

Look for any fall in the floor towards a door or a drain, and record any gully, channel or grating within the building.

Floors laid for washing down or for vehicles often slope deliberately, which matters once furniture and finishes are considered.

Record any damp staining at the base of the walls or on the floor, noting whether it appears after rain or is present all the time.

Observations across different weather are something only an occupier can supply and they are genuinely useful to an investigator.

The cause of any dampness in an outbuilding can only be established by a qualified professional on site, not from what it looks like.

Ask a qualified professional what they would want to know about the existing slab before a new use is considered, and how they would go about finding it out.

What lies under a slab is unknown until someone opens it, and the answer often shapes the whole approach.

What is beneath an existing floor slab cannot be assumed. Any question about altering or building on it is for a qualified professional.

Write down what the roof is covered with, whether it is pitched or flat, and note any slipped, cracked, patched or missing areas.

Roof condition and type shape the extent of the work and are usually visible from the ground or from an upstairs window.

Stand inside with the lights off and note anywhere daylight is visible through the roof, the walls or around the doors.

This is the quickest and most honest test an owner can carry out, and it produces a list of exactly where the building is open.

Note whether the building has gutters and downpipes, whether they are connected to anything, and where water currently discharges.

Water discharging at the base of a wall explains a great deal of what is found inside, and it is easy to observe during rain.

Record whether the underside of the roof shows condensation, staining or rust, and whether stored items have suffered from moisture.

Condensation behaves differently from a leak, and describing what you see helps a professional distinguish between them.

Note whether any lining or insulation has been added previously, how it was done and whether it looks damaged or damp.

Earlier attempts to make a building usable often tell you where the problems are and why the previous approach did not last.

Ask a qualified professional what the existing walls and roof would need for the use you have in mind, rather than assuming they can simply be lined.

Lining a cold building without a considered approach frequently moves a moisture problem rather than solving it.

How an existing outbuilding is made warm and dry is technical design work. No approach is suggested here and none should be assumed to suit your building.

Walk from the house to the outbuilding and note in rough terms how far it is, what the route crosses and whether it is paved or planted.

Everything that has to cross that route becomes more complicated the longer it is and the harder the ground is to open up.

List what would have to reach the building, such as electrical supply, water, waste or a connection for data, and note which already exist.

Supplies to an outbuilding were commonly put in with a single light and a socket in mind, which is a very different proposition from a room in daily use.

Any question about extending electrical supply, water or waste to an outbuilding belongs with qualified installers and the relevant undertakers.

Record what supply the building already has, where it enters and whether you know when and by whom it was installed.

Old informal supplies to outbuildings are common, and their history matters to whoever assesses them.

Consider whether the household would use the building willingly on a wet, dark evening, given the route between it and the house.

The honest answer to this often determines whether a converted outbuilding gets used or gradually reverts to storage.

Note whether the route is lit at all after dark, and whether anyone would be carrying things along it with both hands full.

An unlit route with an awkward surface is what stops a converted outbuilding being used in the evening, whatever the room itself is like.

Note the position and rough proportion of the main opening, what closes it now, and which way it faces.

The main opening usually faces the least useful direction for a room, since it was placed for vehicles or access rather than for light.

Consider whether you would want glazing, a solid wall or a smaller door in that opening, and write down what each would mean for the room inside.

Filling a large opening is not neutral work, and the choice affects light, warmth, privacy and the appearance from outside.

Ask a qualified structural professional what currently spans the main opening and what any change to it would involve.

Owners routinely assume a large opening can simply be filled or widened, when what sits above it governs the options.

Say nothing to a supplier about filling or widening this opening until a qualified structural professional has looked at what sits over it.

Record every other window, door and vent in the building, which way each faces and what it looks at.

The existing openings tell you how much daylight the building has and from where, which is the starting point for any layout.

Consider whether any new opening would look directly at a neighbouring window, garden or seating area, and note where it would face.

Outbuildings usually sit closer to boundaries than the house, so new openings raise privacy questions more quickly.

Write down whether the building is visible from the street or from a shared access, and how much its appearance matters to you.

Visibility from public places tends to influence how a scheme is presented and how neighbours respond to it.

List what is stored in the building now, from garden equipment to bicycles and household overflow, and decide where each category would go.

Displaced storage does not evaporate. It reappears in the new room, in the garden or across the hall of the house, usually sooner than anyone expected.

Note whether the building is used for parking a vehicle, and if so where that vehicle would go and whether parking outside is controlled.

Losing covered parking is a significant change to how a property works and may raise questions with the local authority.

Losing a parking space may be treated as a change in its own right. Ask your local authority what that means here rather than assuming it is a private matter.

Record whether any meter, boiler, tank, pump or consumer unit sits in the outbuilding and photograph each where it stands.

Plant located in an outbuilding is easily forgotten in a sketch and often cannot simply move to a convenient corner.

Note whether the building is used for messy work, hobbies or a trade, and where that activity would take place afterwards.

Activities that need a rough, tolerant space rarely sit comfortably in a finished room, so they need a new home named in advance.

Consider whether the building currently shelters bins, fuel, tools or a bicycle, and where those things would be kept instead.

The small sheltered functions of an outbuilding are the ones nobody lists, and they reappear immediately after conversion.

Write down what the converted building is for in plain words, and note who would use it and at which times of the morning, afternoon or evening.

A specific description lets a designer test the building against the use, rather than designing for a vague idea of extra space.

Note whether anyone would sleep in the building, even occasionally, since that changes the nature of the questions entirely.

Sleeping accommodation raises safety, escape and consent questions that a home office or store does not.

Sleeping accommodation in a converted outbuilding raises safety and consent matters to confirm with qualified professionals and your local authority.

Consider whether the building would be used independently of the house, by someone other than the household, and record the honest answer.

Independent occupation changes how the space is treated in almost every respect, and it is worth stating openly from the start.

Whether a converted outbuilding may be occupied independently is a question for your local authority and a qualified adviser to answer locally.

Note whether the intended use would be at its noisiest early in the morning, late in the evening or at the weekend, and which neighbouring rooms sit closest to it.

When the noise happens matters as much as how loud it is, since an early or late activity in a building close to a boundary is what neighbours actually object to.

Write down how warm you expect the building to be and whether you expect it to be usable in the coldest weather.

Expectations about warmth drive the fabric questions, and stating them early prevents an uncomfortable surprise later.

Put the photographs, the sketch and the condition notes into one file, and send it ahead so nobody arrives without knowing what they are looking at.

Sending the record in advance means the first visit is spent on the difficult parts of the building rather than on the introductions.

Set aside every enquiry about changing what this building is used for, since those belong with the local authority and with nobody else.

A change of use is the part owners most often treat as settled because a similar building nearby appears to have been converted without difficulty.

Write down what you would gain and lose by replacing the building rather than converting it, and ask a professional to comment on both.

Comparing the two options openly avoids the trap of committing to conversion simply because the structure is already standing.

Put the things you do not yet know in order of how badly each one would derail the idea, and deal with the most damaging of them first.

Ordering the unknowns by consequence rather than by curiosity keeps the enquiry proportionate and stops the whole building being investigated at once.

Record who in the household keeps the file of photographs, notes and professional advice, so nothing is held only in one person's memory.

Projects that run over a long period suffer badly when information lives in scattered messages and recollections.