So the only way to get a door open when you re on the outside and it s locked from the inside is to remove the door from its hinges.
Removing upvc door from hinges.
Open the door to 90 degrees from the frame and lift the door upwards.
If stiff you might want to use a crow bar to lever from underside of the door.
If the door is triple hinged take out the middle one first.
Best of all it only requires a hammer and a small screwdriver.
Don t worry removing a door from its hinges is an easy task that can be done in under a minute.
For the sake of stability take off the bottom hinge first followed by the top.
There will be covers fitted over the hinges which can be removed either by sliding the cover off exposing screws holding the hinge to the face of the door or the hinge covers could be screwed on in which case there will be little screws to the outside edge of the hinge facing the ingle once you have the hinge.
If concealed fixed pin hinges.