Internal Door Fitting & Hanging in North West London

How is a new door hung in an existing frame?

A new door is cut to the frame it is going into, because few frames are the size printed on the door label. We measure each opening at three heights, then take the door down evenly from both long edges and from the head and foot. Taking it all off one side leaves an off-centre door that looks wrong once the handle is on. The gap should be tight and even down both sides and across the head.

A door that binds paints itself shut, and one with a wide gap rattles and lets light through. Then the hinges are recessed, the latch is bored in and the strike plate is set so the door closes on a light push. Buying the doors yourself is fine. Check the size against the opening before you order. Standard doors come in imperial and metric sizes, and an imperial door rarely suits a metric frame.

How much can a door be trimmed?

Only as much as the door's construction allows, and a hollow-core door allows the least. Hollow-core and many moulded doors have a solid timber edge round a cardboard or honeycomb core. Trim too far and you cut into the void, the door weakens and the hinge screws have nothing to bite on.

The manufacturer's instructions give the limit for that door. Solid timber and solid-core doors can usually take more off, but they are heavier. Where an opening is badly out of size, the better answer is to pack or adjust the lining, or to order a door made to fit.

Should internal doors be undercut for ventilation?

Yes, in most homes. Approved Document F asks for internal doors to allow air to move between rooms, with a free area equal to a 10mm undercut on a 760mm wide door. That means 10mm above the floor finish where the finish is down, or 20mm above the bare floor where it is not. It applies to new homes, and to existing homes where ventilation work, such as a new wet room, is carried out. The 2026 edition, which takes effect on 24 March 2027, keeps the same figure.

Even where the rule does not strictly apply, an extract fan in a bathroom or kitchen needs air to come in under the door. So we trim to clear the finished floor. If new flooring is going down, tell us its thickness, or book the doors after the floor. Fire doors are the exception. Their gap at the foot is set by the door's test evidence or the council's standard, not by Part F. See our fire doors page.

When do the frame and lining need replacing?

Replace the lining when it is split, out of square beyond adjustment, or chewed up by years of rehung hinges. Otherwise keep it. A new door in a tired frame can be made to work by filling old hinge recesses with timber and resetting the stop. A frame twisted by a building's movement, or one that no longer matches a new door size, is better replaced.

A new lining means taking off the architrave, cutting out the old frame, setting the new one plumb and square, and fixing new architrave. That usually means some making good to the plaster at the edges and decorating afterwards.

Can period doors be rehung rather than replaced?

Usually, and in a Victorian or 1930s house it is often the right call. Four-panel Victorian doors and 1930s doors with glazed panels are hard to match new. A door that drags is usually dropped on worn hinges or has swollen, and a door that will not latch often just needs the strike plate moving. We rehang on new hinges, plane only where needed, splice in timber where an old lock or hinge has split the edge, and adjust the stop.

When an original door is moved to a different opening, it will need cutting to fit. If it is too small, it needs timber added, which shows under paint unless it is done carefully.

What about glazed doors?

Glass in a door needs to be safe if someone falls against it. Approved Document K treats glazing in doors as a critical location from the floor up to 1500mm. In that zone, glass should either break safely, be robust, be in small panes or be protected. In practice that means toughened or laminated safety glass. If an old door has a plain glass panel and you want it kept, we can reglaze it with safety glass when it is rehung.

When does an internal door need to be a fire door?

Some internal doors in houses have to be fire-resisting, and replacing them with ordinary doors undoes that protection. Under Approved Document B, a house with a storey more than 4.5m above ground needs a protected stairway, which is why loft conversions get fire-resisting doors (minimum E 20) onto the stair. A door between a house and an integral garage should be E 30 Sa with a self-closing device.

In an HMO or a block of flats, doors on the escape route are usually fire doors as well. If you are swapping doors in a house with a converted loft, a garage, or a shared house, check which doors are fire doors before you buy. We fit those to a different standard, covered on our fire doors page.

Can you hang pairs and French doors?

Yes. A pair of doors is less forgiving than a single door, because both leaves have to meet evenly in the middle and sit flush with each other. We hang the pair together, set the meeting gap so it stays even from top to bottom, and fit a rebate or astragal so they close neatly.

One leaf is held with flush bolts top and bottom, and the other latches to it. Internal French doors with glass also need safety glass in the critical zone. Heavy glazed leaves need stronger hinges, or a third hinge, to stop them dropping over time.

What affects the cost of fitting internal doors?

The main things are the number of doors, how much each needs trimming, and whether the existing frames can be reused. Hanging a standard door in a good frame is quick. A heavy solid door, a pair, a door cut to an odd opening or a period door needing repair takes longer.

New linings and architrave add the most time, along with the making good that follows. Ironmongery matters too: a simple lever handle is quick, while a sashlock or mortice bathroom lock takes longer to cut in. If we supply the doors, their price is part of the total.

Certificates and defined jobs are a fixed price confirmed before we attend; repairs are charged by the hour, with the rate and an estimate confirmed before we attend.

Where we hang doors

We hang and replace internal doors across north west London: Harrow, Kenton, Stanmore and Edgware first, then Pinner, Wembley, Kingsbury, Mill Hill, Hendon and nearby. In the 1930s semis that fill much of this area, the work is often rehanging original panelled or glazed doors, or replacing a mix of mismatched doors with a matching set. In newer flats it is usually swapping dated doors for new ones in sound frames. For landlords, a set of doors can be timed into a void between tenancies.

Carpentry & Joinery by area: Carpenters in Harrow, Carpenters in Kenton, Carpenters in Stanmore, Carpenters in Edgware, Carpenters in Bushey, Carpenters in Colindale, Carpenters in Hendon, Carpenters in Mill Hill, Carpenters in Northolt, Carpenters in Northwood, Carpenters in Pinner, Carpenters in Ruislip and Carpenters in Wembley.

What we will not do

We do not knock through walls to make new openings, as that can be structural; we refer it to a structural engineer and builder. We will not replace a fire door with a standard door, or fit a door that blocks an escape route. We do not issue fire door inspection certificates. We are not an emergency locksmith; planned lock changes are covered on our lock change page.

Why people trust us

• Electrical or plumbing items on the list go to a registered electrician or one of our plumbers, on the same visit where we can
• A walk-in office on Kenton Lane, not a serviced address
• A written specification, so you know what is included and what would count as an extra
• A time slot rather than a morning-or-afternoon window
• Work photographed before and after, and reported
• We tell you when you do not need something we sell

We are building a review profile under this name and would rather show you none than borrow someone else's. Ask us for references from landlords and we will put you in touch.

Official sources

• GOV.UK: Approved Document F (ventilation), Volume 1: Dwellings, 2021 edition, paragraphs 1.25 and 3.27
• GOV.UK: Approved Document F (ventilation) publications, including the 2026 edition
• GOV.UK: Approved Document B (fire safety), Volume 1: Dwellings
• GOV.UK: Approved Document K (protection from falling, collision and impact), section 5 glazing

Last reviewed October 2026 by EliteShires Property Services.