Clarification please.

Do you mean parked in front of the exit, or just parked nearby?

Not an expert but quickly found this on internett:

3.20: Widths of escape routes and exits

Maximum Number of Persons = 60 the Minimum Width (mm) = 750

Maximum Number of Persons = 110 the Minimum Width (mm) = 850

Maximum Number of Persons = 220 the Minimum Width (mm) = 1050

More than 220 then 5mm per person

Edited by user 15 April 2021 15:14:10(UTC)  | Reason: Table did not read correctly

Its illegal to lock fire exits or obstruct fire exiting while a building is occupied. If where the vehicles are parked amounts to blockage, then you have your answer.

Emergency routes and exits

14.—(1) Where necessary in order to safeguard the safety of relevant persons, the responsible person must ensure that routes to emergency exits from premises and the exits themselves are kept clear at all times.

https://www.legislation.gov.uk/uksi/2005/1541/article/14/made

However there is no definitive set distance a vehicle must be separated from the final exit door (Approved document B / BS 9999) so it comes down to the good old favourite of Risk Assessment - how many people, how quickly, able bodied or otherwise.......

The standards only refer to having a BS safety barrier where a final exit emerges directly on to a roadway.

Personally we always "hatch" the whole parking space immediately in front of any fire exit - doesn't stop the idiots which is where I suspect this post originates with its talking about a shared yard.

Well again its down  to the risk assessment.  If the fire exit is likely to be used a by a few people than a 1 metre gap between the cars and the fire exit might not be an issue. On the other hand  if hundreds of people need to get through those doors then you want as much open space for them as possible.  

Originally Posted by: Ian Bell2

Its illegal to lock fire exits or obstruct fire exiting while a building is occupied. If where the vehicles are parked amounts to blockage, then you have your answer.

Emergency routes and exits

14.—(1) Where necessary in order to safeguard the safety of relevant persons, the responsible person must ensure that routes to emergency exits from premises and the exits themselves are kept clear at all times.

https://www.legislation.gov.uk/uksi/2005/1541/article/14/made

That is true, but this offence (article 14) can only be committed by a Resp Person or employee.  There is no offence committed by a non employee car driver under the Fire Safety Order who blocks a fire exit. (see Article 32)

Article 14 (quoted above) requires the Responsible Person to ensure there are fire exits. So If a car has parked there and the RP has not applied any measures to stop the parking, its an offence under Article 14 for the Resp Person NOT the car driver

When a fire safety inspector, I was asked many times to attend where a neighbour has blocked an exit. This was common on my city centre patch as we had numerous over-height single staircase buildings of 5 or 6 floors that had an escape route over the roof and into a neighbouring property

Next door would move out and the new occupiers wanted nothing to do with the arrangement (who can blame them not wanting an unlocked door into their property?). I would ask for a voluntary agreement not to use the upper floor(s) or if not, I would be forced to serve a notice on the poor sould who had asked for help and NOT the neighbour who blocked the exit

Some drivers who park close to the fire exit may not be aware it is a fire exit.  Signage on the outer face of the door may stop this also as mentioned above if you are allowed to, hatch the space beyond the door in yellow paint as well as fitting the sign/s.

You should also regularly monitor the fire exit/s to ensure they are not blocked and if they are locate the culproits and ask them to move their vehicle.

Don't forget to record you checks and the Reg. No. and name of anyone spoken to.