The Crime Prevention Website


Basement flats have their own section here because they suffer from some rather unique security problems.  In Central London and the centres of many other cities it is common to find large Victorian terraced homes with basements.  Some of these basements would have housed the kitchen and scullery and accommodation for the servants along with rooms in the loft.  A majority of these basements have now been converted into flats and most make use of the original separate entrance via steps that lead down from the footway above – the tradesman’s entrance.  Larger basements will be deep and there will be railing or a wall (but normally railing) running along the back of the footway to stop people falling in, unless you are in Amsterdam where many of them have no barrier at all!  

The obvious problem with basement flats is that people living above or walking along the footway tend not to see what’s going on down below; natural surveillance, an important weapon in the fight against crime is simply missing.  In my experience many of these flats either lack some of the most basic security measures or they are so secure that the residents would find it difficult to escape in a fire.  There are number of things that can be done to make up for the lack of overlooking and the ready access and they are listed below.  The most important consideration though is your ability to escape from the place in an emergency so you must keep this in mind when planning the security improvements.

Above and below ground image of basement flats

Window locks and grilles etc.

  • Retro fitted window locks may not be sufficient for this risk so consider either installing collapsible gates or removable grilles on the inside of the existing windows.  If you don’t want to do this then consider replacing the windows with ones that are certificated to BS 7950 for enhanced security and make sure they are glazed with a laminated glass on the inside of the sealed unit to at least 6.4mm thick. (See  Glazing for domestic security )    Many of the windows will be vertical sliding sashes and BS 7950 replacement ones are now available.  (See  Window security,  Windows of enhanced security)
  • In exceptional circumstances you could do both and this is obviously best done if you are carrying out some major refurbishment or your landlord is incredibly generous
  • If your windows have fixed, external ‘burglar bars’ then make damned sure you can get out of the main entrance door at all times.  You’ll need smoke detectors and door closers on all your doors to make sure that you wake up and you can get to the exit.  That said I think that this is a requirement for anybody living in a basement flat
  • If you are unable to do any of the above then make sure the windows are fitted with locks and have an intruder alarm installed.  You could install an alarm anyway, but it seems to be even more essential if you are only relying on window locks

Entrance door

  • The entrance door should be secured in the manner recommended in  Door security, Improving the security of your existing doors  Entrance doors to basement flats , with reference to Building Control about your arrangements for escaping in an emergency.  If you have the cash then the entrance door should be replaced with one that is certificated to PAS 24 or to the higher standard of LPS 1175 SR2, which will have the added bonus of glazing that is very resistant to breakage (quite expensive though!)
  • Some basement flat entrance doors are located beneath bridged steps that give access to the main entrance door to the rest of the building above.  Historically, this may have been done to provide shelter for tradesmen when calling at the ‘tradesman’s’ entrance, but unfortunately this puts the door even more out of sight from the road.  If you or your landlord are intending to make alterations to the flat then repositioning the door by 90°, so that it can be seen from the street above would be a useful crime prevention improvement, apart from providing an extended hallway. Planning permission is probably required


  • Lights are an important requirement for basements.  What little chance there is of people being seen down there has to be highlighted as best you can.  It would be best to use low energy lamps operated via a dusk to dawn switch and if you don’t like lights outside your windows then think about lining the curtains with black-out material like I have done at my house to reduce the glare from the street lamp.  (See Lighting )

Access gate

  • To stop people getting down into the basement in the first place you need to lock the gate at street level, if you have one.  This is easier said than done, due to your need to escape from the dwelling in case of a fire or other emergency.  A lot of these gates are fitted with mortice sashlocks and if your household is the sole user of the gate then you could lock the gate at night, but you’ll have to make sure that the key is available to everyone in the flat.
  • To make certain that you can escape in an emergency it would be better to use a sash lock with a shielded thumb turn on the inside of the lock (instead of a key hole) that can’t be accessed from the street side.  This means that other people using the gate can easily get in and out using a key from the outside and the thumb turn from the inside.  You’ll almost definitely need the services of a Master Locksmith for this job.  Another option, which will be a little expensive, would be to install an electromechanical lock into the gate that is released by an access control fob or the fire alarm should it go off.  I’m sure you can see that there are lots of things you can do to keep yourself safe – if you’re willing to spend the money that is.
  • If there are railings at the back of the footway preventing people from falling into the basement you might be able to increase the height by installing new ones, but you will almost certainly need planning permission.  If the railings are flat topped you could weld a finial topping on top to make them more difficult to climb over.  There is a high chance that you won’t be able to do this because the majority of these Victorian homes are in conservation areas, but it’s worth a shot.