On 09/10/2020 12:23, NY wrote:
snip

It would have been better if those locks had been designed so you *can*
put a key in from the outside and open the door, while still leaving a
second key in the inside lock in case you need to exit in an emergency.
They could have a slide-latch which disables opening from the outside if
required for extra security when you know that everyone who lives in the
house is safely inside.

They may also have thought it wd not be better in some rarer but
important cases: eg you lost a key with your address and haven't had
time to get the lock changed; you've a violent partner you want to keep
out for a while; you don't want to be caught in the act.

--
Robin
reply-to address is (intended to be) valid