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Greenwich Lock Installation
Lock Installation across Greenwich and the surrounding Greater London area, 24/7, any day of the year — average response 15 minutes. Free call-out with every job — fixed price agreed before any work starts.
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All services in Greenwich →A security survey on a Victorian terrace front door assesses more than the primary lock: the condition of the nightlatch, the letter plate flap security (a flap through which tools can be introduced), and the glazed panel configuration are all noted. The survey drives the scope of the fitting visit rather than arriving with a predetermined hardware list that may not suit the actual door.
On arrival
Measurement checklist: what we record on arrival
Four measurements are taken before any hardware comes off the van on a Greenwich installation. A wrong-part revisit costs more than two minutes of careful measuring — we never skip this step.
| Measurement | Why it matters | Typical range |
|---|---|---|
| Stile width | Sets which door edge prep case will physically fit without weakening the door at the lock rail. Victorian timber stiles dry out and shrink over decades — the door may have been planed once before; check the edge thickness before specifying a mortice with a tight forend. | 44 mm minimum for a full BS3621 mortice; narrower stiles may require a slimline case or a euro-cylinder alternative |
| Frame recess depth | Victorian terrace door prep: check the door edge for square (measure the gap at the hinge side, top and bottom), confirm the rebate face is flush with the frame, and assess the stile clearance before sizing the mortice or nightlatch. | 13–20 mm on most residential timber; composite and UPVC frames can run shallower |
| Door thickness | Controls the cylinder length from face to face. A cylinder sitting proud of the outer face — even by 3 mm — creates a snap-attack leverage point that defeats anti-snap ratings. | 44 mm (standard timber), 54 mm (solid composite), 70 mm (hardwood or fire-rated) |
| Cut-out position | The distance from the door edge to the centre of the existing cut-out sets the backset. Extending an existing cut-out adds time and cost; fitting into the existing position is preferred wherever the hardware allows it. | 45 mm backset (most residential); 60–70 mm on commercial and period doors |
All four measurements are recorded on the job card and referenced in the installation certificate. If the measurements reveal a door that cannot accept the specified hardware without prep work, that is flagged and quoted before any tools come out.
Before quoting
Six door conditions that change the Greenwich quote
The stile depth on a Victorian terrace door affects which case sizes are available at the BS3621-compliant grade. Narrower stiles may require a slimline certified case that carries a small premium over the standard body size. This is identified during the pre-fit measurement and factored into the confirmed price before the first screw is turned. From £59 for a standard installation on a door in good condition.
- 01 Narrow stile
Victorian terrace flat entrance doors in Southwark that were converted from sliding room dividers into hinged flat doors can have a very thin stile — sometimes under 35 mm — because the sliding door construction uses a thinner profile than a standard entrance door. These doors are assessed for structural adequacy as a flat entrance before any lock specification is made; where the stile is under 38 mm the customer is advised that the door itself may need replacement.
- 02 Composite vs timber construction
Composite and UPVC doors use a different cylinder system from timber — euro profile with a multipoint gearbox rather than a mortice. Hinge adjustment before lock fitting prevents the mortice from being blamed for binding — close the door and check the gap is consistent top to bottom before starting. Confirming construction type before ordering avoids a wrong-part visit.
- 03 Existing cut-out dimensions
Paint build-up on period front doors in Wandsworth and Haringey can add several millimetres to the door face around the existing forend, making the apparent pocket narrower than the timber beneath. The forend recess is measured to the bare wood — any paint build-up inside the recess is noted and the true dimension is used when sizing the new forend so that it sits flush rather than proud of the door face.
- 04 Nightlatch position
Paint-obscured fixing holes are common on period front doors in Wandsworth and Haringey that have been repainted many times without stripping. The stile face is probed with a thin bradawl at the intended backplate position to detect any hidden screws or filled holes before marking centres for the new fixings, avoiding the risk of splitting the timber if an old plug or screw is struck during drilling.
- 05 Frame condition
We check the door edge for square the frame for squareness, settlement, and rebate wear before committing hardware to final position. A frame that is out of square or has a worn rebate needs addressing first — fitting a mortice into a moving frame produces a bolt that binds within months.
- 06 Letterbox clearance
Communal letterbox banks at street level in Hackney and Southwark HMO buildings mean that individual flat doors may not need a letterbox at all. Where a flat entrance door has a redundant letterbox from previous use as a single-family home, the aperture clearance check confirms whether the slot creates a security or draught risk; it can be blanked with a matching period-style cover plate rather than left open.
Specification
Hardware compatibility: will this door accept BS3621?
Three questions answer most hardware compatibility conversations on a Greenwich installation. We work through each on arrival and confirm the spec before any cutting or drilling starts.
- 01
Can this door accept BS3621?
A BS3621 5-lever mortice requires a minimum stile width (44 mm), a frame rebate to accept the forend, and sufficient door thickness at the lock rail. We check all three before specifying — a door that cannot take a BS3621 case without structural compromise will be quoted with a compliant alternative using a door edge prep or stile clearance instead.
On period terraces in areas with high humidity, timber doors swell seasonally — if the visit is in summer, the door may bind in winter without allowance at the planing stage.
- 02
Cylinder size: 35/35 vs bespoke
Standard residential doors run 35/35 or 35/45 euro cylinders; composite and commercial doors often need bespoke lengths. We assess the stile clearance the cylinder run on site — face to face across the door leaf at the lock rail — and confirm the planing margin specification before fitting. An oversized cylinder leaves the anti-snap collar exposed.
Anti-snap cylinders must be sized with the break-point inside the door face. A cylinder that is even 3 mm too long on the outside is vulnerable to a snap attack regardless of its anti-snap rating.
- 03
Nightlatch: rim vs mortice
Rim nightlatches surface-mount on the door face and require backplate clearance from the door edge and from any adjacent furniture. Mortice nightlatches fit into the door thickness and suit doors where the face is already occupied by a letterbox or knocker. The choice depends on the stile geometry confirmed at measurement, not a preference.
On insurance-graded installs both the primary lock and the nightlatch are noted on the compliance certificate. If the policy specifically names a rim nightlatch at a given standard, we confirm that against the door construction before the certificate is issued.
Completion
Handover and testing
The installation is not complete until every lock has passed a full function test on a closed door. On Greenwich jobs we sign off three checks before handing back keys.
- Cycle test
In Wandsworth and Haringey, Victorian terrace doors that were re-hung during flat conversion may sit in a frame that is not perfectly plumb due to settlement of the converted building. The cycle test is performed with no manual force applied to the door edge; if the bolt requires any shoulder push to engage the keep, the keep position is re-shimmed before the final test pass is recorded.
- Key issue
Keys are counted against the job card in front of the keyholder. Each key is labelled with the door reference it was cut for. No key leaves site unaccounted — if the agreed number is not present at handover, the job card flags the discrepancy before the engineer leaves.
- Written summary and certificate
Communal entrance door installations in Islington and Camden HMO buildings require the handover to be co-signed by the property manager on site where possible, or by email confirmation where the manager is not present. The co-signature confirms that the communal key allocation has been agreed and that all current tenants have received their key before the engineer leaves the building.
Questions
Lock installation FAQ: Greenwich
The most common FAQ on a period terrace front door is whether it can meet the insurer's BS3621 requirement. The answer depends on the stile width: a narrow Victorian stile — common on smaller terrace houses — may not accept a full BS3621 5-lever case without reducing the door strength at the lock rail. Where that is the case, a narrower BS3621-certified case or an alternative compliant spec is the right answer, not forcing an oversized mortice into a door that cannot support it.
- Do I need to measure my door before calling?
- All site measurements are taken at the start of the installation visit. Islington and Camden HMO communal doors are measured with the door in its habitual resting position — which may be slightly ajar due to a weak closer — because the bolt alignment needs to reflect the position the door is in when it is pulled shut by a resident, not the ideal square-in-frame position that the door may not reliably achieve.
- Will the new lock look different from the original?
- On like-for-like replacements — same case position, same forend size — the external appearance changes only in terms of the new cylinder rose or escutcheon. On period doors where the original furniture is being retained, the escutcheon fit is checked for compatibility before the hardware is sourced. Where the new spec requires a different door face profile (e.g. switching from a mortice keyhole to a euro cylinder profile), we flag that on the booking call before the job date.
- How long does a Greenwich lock installation take?
- A standard like-for-like cylinder replacement on a composite or UPVC door takes around 30–45 minutes including the full test cycle. A new BS3621 mortice installation on a timber door — where the existing cut-out is the right size — takes 60–90 minutes. If the door needs prep before the hardware fits (rebate adjustment, aperture extension, hinge correction) we agree the additional time and cost before starting. We do not proceed past the assessment stage without a confirmed price.
- What if the door needs repair work before the lock can be fitted?
- Paint build-up on Victorian terrace doors in Wandsworth and Haringey can reduce door clearance to the point where the door sticks in the rebate and the bolt cannot reach the keep. Before the new lock position is cut, the door edge clearance is measured on all four sides; where clearance is under 2 mm the door edge is eased with a plane and the paint build-up in the rebate is pared back to restore free movement.
Lock Installation in Greenwich — FAQ
Common questions about lock installation in Greenwich.
Can you install a lock on a brand-new door?
The most common FAQ on a period terrace front door is whether it can meet the insurer's BS3621 requirement. The answer depends on the stile width: a narrow Victorian stile — common on smaller terrace houses — may not accept a full BS3621 5-lever case without reducing the door strength at the lock rail. Where that is the case, a narrower BS3621-certified case or an alternative compliant spec is the right answer, not forcing an oversized mortice into a door that cannot support it. Yes — this is one of our most common installation jobs in Greenwich. Carpenters and joiners often hang the door and leave lock fitting to specialists. We measure the rebate, chisel for a BS3621 mortice case, fit the strike plate, and test through a full key cycle. Finished work looks factory-fit.
Do I need BS3621 on a new installation?
For external doors on Greenwich homes with standard insurance — yes, almost certainly. BS3621 is the minimum most UK home insurers specify on final-exit wooden doors. We fit BS3621 as standard and issue written paperwork confirming the standard for your insurance file.
Can you keyed-alike multiple new locks?
Yes — if you want one key to open your front and rear doors, we supply keyed-alike cylinders on the most common profiles. Arrange at the survey stage so we bring matching parts. This works cleanly on UPVC euro cylinders and on certain mortice profiles.
We've just moved into a new-build in Greenwich — do the locks already meet insurance standards?
Not always. Many Greenwich new-builds come with entry-level euro cylinders on UPVC or composite doors that lack the TS007 3-star anti-snap rating, and sometimes a mortice case that predates BS3621 on the side door. We survey the whole property, identify any hardware gaps, and upgrade to compliant standards on the same visit — with a compliance pack for your insurer.
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Areas near Greenwich
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