Locks for a filomuro door: magnetic, bathroom or key

Kulttur Team · Published: 13 August 2026

The hardware on an invisible door is chosen before the door goes into production, not after installation. A leaf built on an extruded aluminium frame is machined at the factory for one specific lock body, and the frame receives the matching strike plate in the same step. Below are the four locking options used on filomuro doors, how they map onto rooms, and the figures your order needs so nothing has to be improvised on site.

What a magnetic lock means on a concealed-frame door

On a conventional lock, the latch protrudes permanently under spring pressure and retracts when you press the handle. You hear a click on every closure, and the latch rubs the strike plate until it polishes the surrounding finish. On a magnetic lock, the latch sits retracted inside the body and only shoots out once it reaches the strike, pulled by a permanent magnet. Closing sounds muted rather than clicking, and the door edge stays clean.

On a filomuro door the difference is not only acoustic comfort. The perimeter reveal of roughly 3 mm on the vertical sides leaves very little margin for error: a permanently protruding latch touches the frame on every swing and marks the edge over time. A retracting latch removes that contact until the very last millimetre. That is why the magnetic lock became the default on concealed-frame doors, while mechanical bodies stay for situations that need genuine resistance to forcing.

The four locking types used on filomuro doors

All four fit the same pocket machined into the aluminium frame, but they differ in what happens when you want to secure the door. The table compares them on the criteria that matter at order stage.

If you want no handle at all, the discussion moves to push systems and slim recessed pulls, where the door opens by pressure and locking is only possible through a separate bolt. The two decisions are linked, because the machining in the leaf differs from one solution to the other.

Choosing by room

The practical rule is simple: fit a lock only where you genuinely need one. Every locking mechanism adds a moving part that can fail and a visible element on a door designed to disappear into the wall.

• Living room, hallway, dressing, storage: plain magnetic. Nothing to lock, nothing to adjust later, clean surface.
• Bathroom: magnetic with a thumbturn, always with an emergency release from outside. Material matters as much as mechanism here, and the notes on filomuro doors in wet rooms are worth reading before ordering.
• Bedroom: thumbturn if you want privacy, plain magnetic if you do not. A key cylinder in a bedroom is rarely justified.
• Home office, plant room, server room: key cylinder. Here locking has a real reason: equipment, documents, controlled access.
• Clinic, rented space, reception: electronic lock, provided there is budget for wiring and maintenance.

What is machined at the factory and cannot change on site

This is the major difference from a classic timber door. In a solid wood or MDF leaf, a joiner can rout a new lock pocket on site. In an extruded aluminium frame with a mineral wool core they cannot, or not without compromising the rigidity of the leaf and the warranty.

Fixed at order stage: lock type, pocket height, cylinder centre distance, handle type and the side it sits on, which follows the opening direction. The frame is machined as a mirror image for the strike, and the concealed hinges go on the opposite edge. A leaf delivered with a plain magnetic pocket cannot later take a key cylinder without replacing the lock body, and if the machined pocket is shorter than the new body, there is no clean way out.

Backset, centre distance and handle height

Three figures appear on every hardware order and are worth understanding, because they decide whether the handle and the key land in the same holes.

• Backset, the distance from the door edge to the handle spindle. The usual value on interior doors is 50 mm, dropping to 45 mm or even 35 mm on slim lock bodies.
• Centre distance, between the handle spindle and the cylinder axis. The European standard is 85 mm, with 90 mm as the second common value. If the lock is 85 and the rose is 90, the parts do not line up.
• Handle height measured from finished floor level, usually 100 to 105 cm. On a floor-to-ceiling door the handle stays at the same height, otherwise the proportion of the leaf reads wrong.

A European cylinder has a 17 by 33 mm profile and is ordered by length, for instance 30/30 or 30/35 mm, depending on leaf thickness. On filomuro doors with a 40 to 45 mm leaf, a cylinder that is too long protrudes past the rose and shows, while one that is too short fails to engage the cam.

An electronic lock on a filomuro door: what to settle first

A smart lock on an invisible door is feasible but needs three things fixed at design stage. First, power: battery versions inside the handle are the simplest, wired ones need a route through the frame and a supply point in the wall, so the decision comes before plastering. Second, the extra mass on the leaf, which shifts its balance and calls for correctly sized hinges. Third, the finish: a stainless electronic module on a leaf sprayed in matt RAL breaks visual continuity, exactly the effect a filomuro door is built to avoid.

In practice, the solution that best preserves the look is a wall-mounted reader next to the door with an electric strike in the frame. The door stays a clean surface and the electronics sit outside the main field of view.

Can a key lock be fitted to an already installed filomuro door?

It depends on which lock body was machined originally. If the pocket in the aluminium frame matches a cylinder lock, the body can be swapped and the rose routed. If the door shipped with a plain magnetic lock in a shorter pocket, working on an aluminium leaf has no clean solution and affects the warranty. Check the order specification before buying hardware.

Does a magnetic lock hold the door shut against draughts?

Yes, the holding force of an interior magnetic lock is enough for normal household air movement. On very large doors, or in spaces with strong mechanical ventilation where the pressure difference between rooms is real, a higher holding force body is used or a stop is added. A leaf 100 cm wide by 250 cm high is already in the range where that question belongs to the supplier.

What happens if someone gets locked in the bathroom?

Bathroom thumbturn locks always have an emergency release on the outside, as a slot for a coin or a flat screwdriver. A 90 degree turn releases the bolt from outside. Never accept a bathroom lock without that function, however clean the rose looks.

Is a magnetic lock quieter than a conventional one?

Yes, and the difference is obvious at night. A conventional lock makes two sounds, the latch clicking on the strike and the handle spring returning. A magnetic one leaves only the muted contact of the leaf on the frame seal. On a door with a mineral wool core reaching Rw 35 to 38 dB, silent hardware is the last missing piece of the acoustic picture.

Hardware is one of the few filomuro decisions that cannot be corrected after installation. If you are unsure which lock each room needs, bring the architectural plan to the showroom at Bulevardul Dacia 153-155 in Bucharest, or configure the door online and state the locking requirements in the order. We check them together before the leaf enters production.