Wine Cellar Renovation Cost: What the Money Actually Buys

A renovation is not a smaller new build

A new cellar starts from a room you are creating. A renovation starts from a room you are keeping, and the whole difference is in what you cannot see: what the walls are made of, what is behind them, and whether the floor can take a load.

That is why a renovation cannot be costed from a bottle count. The bottle count sets the joinery and the cooling. Everything else is a function of the room.

Seven work packages, of which three are invisible

Almost every conversion breaks into the same seven jobs. Only the middle three appear in a photograph of the finished cellar.

Why the invisible packages carry more weight than buyers expect

In a conversion the box has to be built inside the room: a continuous insulated, sealed envelope which the joinery then sits inside. That envelope is not a product. It is labour and material applied to surfaces of unknown flatness, and it is priced by square metre of wall, floor and ceiling rather than by bottle.

On a small cellar this is the line that breaks the arithmetic. A two-hundred bottle cellar and a thousand bottle cellar need roughly the same walls; what differs is the joinery standing inside them. So cost per bottle falls steeply as the room gets bigger, and a small conversion is expensive per bottle for a reason that has nothing to do with wine.

The three things that move a conversion quote the most

Two conversions of the same size can sit far apart on price. In our experience the difference is almost always one of these three.

• Whether the room is already dry and thermally stable, or an active source of moisture that has to be dealt with first.
• How much of it is glazed. Glass moves the cooling line, and the cooling line changes the whole layout rather than one detail.
• How much of the surrounding room has to be put back. A cellar carved out of a finished basement costs more than the same cellar inside a stripped shell.

Rooms that were never meant to be cold

Basements, garages, closets and the space under a stair each have one specific problem, and the cost of solving it differs in each case.

A garage slab is uninsulated and swings with the weather, so the envelope does the work and it is thick work. A basement is stable but often damp, so money goes to waterproofing before it goes anywhere near joinery. A closet is the cheapest of the four because it already sits inside the thermal envelope and is usually the smallest. Under a stair is the hardest to make look deliberate, because the geometry fights every rectangle anyone tries to put in it.

Two lines never worth trimming

The vapour seal and the condensate path. Both are modest against the total when they are done properly, and both require the room to be opened up again when they are not.

Everything else can be staged. Lighting can be added later, a second zone can be designed out, and the electrics can be simplified. Sealing cannot be staged, because it is the one job that has to be finished before the joinery closes the room.

Why the cheapest quote is usually the one that assumed the least

Three quotes for a conversion rarely describe the same scope. One has included the strip-out, one has not; one has allowed for a new floor, one has assumed the existing slab can be sealed and left; one has assumed the electrics can be reused where they are.

None of those assumptions is dishonest. They are simply not written down, and they do not surface until the room is open and the answer has to be given on the spot. That is when the price moves, and it moves in one direction.

The cure is a scope list attached to every quote: what is included, what is excluded, and what is provisional because it cannot be seen yet. A quote without that list is a number, not an offer.

When a fitted cabinet beats a conversion

If the room is small, shared with something else, or not yours to alter, a fitted cabinet delivers most of the function without touching the building. It is a box inside the room instead of a room turned into a box, and on a lease that is usually the whole argument.

On a large dedicated space the conversion wins, because the envelope is paid for once and the joinery is paid for per bottle.

How the number is built is set out on the pricing page; what it buys is set out here.