Choosing an entrance door: made to your opening, not off the shelf

A catalogue size, and the hole in your wall

A door sold by size is made before anyone has seen your house, so the number has to be met somewhere. A wider opening gets packing timber behind the frame; a narrower one gets the frame trimmed, then the leaf trimmed to the frame. Both are routine, and both cost something you notice later — reveals stop being equal, and a trimmed bottom rail puts a cut edge where the house is wettest.

The other route reverses the order: the opening is measured first, frame and leaf are drawn from those measurements, and the catalogue never enters the conversation. An opening that tapers a centimetre from head to sill is simply what the drawing records. That matters more here than in a housing stock built from components, because render evens out the look of a wall without evening out its geometry.

What the opening decides for you

Three numbers are never enough. Width at head, middle and sill; height at both jambs and the centre; both diagonals, whose difference is the whole story of how square the opening is. The smallest readings are what a leaf must clear, and the spread between them is what the frame has to absorb. To take them yourself, measuring an opening before anyone quotes it covers the method.

The floor decides the bottom of the door, and it is the detail settled too late most often, so the finished level has to be known on both sides of the opening, terrace step included, before the leaf is made.

Then the wall, above and beside. A wider entrance than the builder framed is a structural question before it is a joinery one, and it belongs to whoever owns the structure. Beside the opening, the clear wall run decides anything that slides — a downpipe or a column three centimetres from the jamb has settled more door layouts than taste ever has.

One leaf, two climates

An entrance door is the only joinery in a house asked to live in two environments at once: one face takes sun and rain, the other sits in conditioned air a few centimetres away. The faces gain and lose moisture at different rates, and a leaf built without allowing for that has no way to express the difference except by moving.

Construction is where the allowance gets made, and it is the part of a door you cannot see once it is hung. A wide leaf built as one glued-up slab fights itself; the traditional answer is a stable frame around panels free to move in their grooves — a humidity strategy wearing the clothes of a style. Every face gets sealed, top and bottom edges included, because an unsealed bottom edge drinks into end grain while the faces stay protected, and that is where most doors begin to fail. Which timber, and whether solid or built-up, is settled on which timbers hold their shape in a big flat panel rather than here.

Hinged, pivot, sliding, or a pair

How the door opens has the longest reach, because it is the decision the building has to answer for. Each option asks something different of the structure, the floor or the wall, and each locks in a hardware choice made before the leaf is fabricated. Interior doors run on the same logic at lower stakes.

The frame, the architrave and the threshold

A door is not a leaf. It is a leaf, a frame, the architraves covering the frame-to-wall junction, and whatever happens at the floor. Made as one job those parts get drawn against each other: the frame set out to the opening's real shape, the architrave chosen to cover the worst of the gap, the leaf cut to the frame rather than to a number. Made separately, each part inherits the last one's errors.

Replacing only the leaf is a reasonable thing to want and often perfectly possible, but it depends on the frame. One still square, sound and properly fixed will take a new leaf made to it; one that has moved with the building, or softened at the bottom of a jamb, will hang a new leaf badly however well the leaf is made.

The threshold deserves a decision of its own, and it is the one most often inherited instead. It is the line where the outside stops, and it settles three things at once: the gap the leaf has at its bottom edge, which way water is persuaded to run off rather than in, and whether there is a seal for the leaf to close onto or simply air. All three follow from the finished floor levels either side of the opening, which is why those levels have to be known before the leaf is made.

The order is what goes wrong. A leaf drawn to a bare screed gets a tiled floor laid under it afterwards, and a gap that was right becomes a gap that fouls; a leaf drawn to the finished tile cannot be hung until the tile is down. The usual rescue is to trim the bottom of the leaf on site, which turns a sealed bottom edge into a raw one at the wettest point in the house — the one face on a door where that matters most. Settling the threshold on the drawing avoids all of it: agree the levels, agree the gap, and let the leaf be made to them.

Hardware is agreed before the leaf exists

Most people meet this in the wrong order: choose a door, have it built, then choose the ironmongery. Door gear does not sit on a leaf. It sits inside one, and the leaf is made around it.

A lock case is mortised into the closing stile, so two leaf dimensions are agreed before fabrication: the thickness the case has to disappear into, and the stile width left either side of the mortise. Make the stile narrow for the look and the mortise takes most of it away. A pivot set is the floor decision above. A sliding track is the wall decision, plus a head detail that belongs to the frame. And hinge specification follows the finished weight of the leaf.

What this page will not do is rank products. No brand, grade or rating is named here, deliberately — that is a different conversation with a different kind of seller. What we can tell you is the joinery consequence, which is the part that becomes permanent. In our own work the gear goes on at the bench, where the leaf is held square and the mortise cut to the case. The cabinet version of all this is the cabinet equivalent of these decisions.

A face that takes sun, and one that does not

The finish is the door's climate suit, and on an entrance it does two jobs on two faces: the exterior one is a wearing part, renewed before it fails rather than after, while the interior face can be chosen for how it looks. Which system goes where is the finish guide's subject, and what to put on a face that takes sun and rain is the comparison worth reading before you decide between clear, stained and painted.

Where it gets finished matters as much as what goes on it. Our painters spray and cure each leaf flat in our own paint shop before it travels, which is the only reliable way the top and bottom edges get coated, and it makes installation day hanging and adjustment rather than sanding in your hallway. The one exposure decision that is not a coating is the roof: an overhang does more for a timber door than any product applied to it.

Doors also sit somewhere in the order of work, and getting that wrong is how a finished leaf ends up as a workbench. where doors land in the whole-interior sequence sets it out with the rest of the trades.

What to send a workshop, and what should come back

Enough can be settled by message to make the site visit productive: photographs of the opening from inside and out, a photograph of a door you like, the drawing if there is one, whether the floor finish is down, and which way the door should open.

What should come back is a drawing you approve and an itemized quote separating leaf, frame and architraves, finish and installation, so you can see what each decision costs rather than one number for a door. And whatever gets measured on site should be measured by whoever will build it — on a Koh Samui site an opening read off a plan is the commonest reason a door arrives the wrong shape.

The scope is worth stating plainly. We measure the opening, draw leaf and frame to it, build and finish both in our workshop, fit the gear at the bench, and hang and adjust the door with our own crew — a door and frame made for one opening is the whole of that offer. Structural work to widen an opening belongs to the builder, glazing to a glazier, gate automation to the installer who supplies the motor. A door chosen this way is not a purchase that arrives — it is a set of decisions taken in order, and the opening makes most of them for you if you let it.