Hello
In summary 
Grade II listed building. Flat at back. Not road facing
Massive leak , rotted window. I replaced sept 22. Got heritage approval . Ok
Window replaced from
Inside as second floor. No access exterior.
14 months later scaffold put up outside to maintain wall as southern wall facing the sea, gets major impact from Weather.
That wall unlike all other walls never maintained in 18 years. Neglected by freeholder and managing agent and reason why window rotted
Freeholder and managing agent never helped or supported me
leak in my flat or assessed it so I replaced window.
Freeholders now saying I should have put lead flaring around the window from outside (no access last year) I’m responsible.
Acknowledged no lead flashing on prev window due as building design fault when building diverted from Synagogue to 9 flats.
So, question
Lead flashing is part of the building structure and not my responsibility. Right?
Window is installed. Also the lease is vague about window maintenance so I paid for window replacement myself- urgent job, v expensive.
Freeholders acknowledg because huge wall never maintained and my window never painted externally (unlike all other flat windows which I contribute towards!) it contributed directly to its rott.
I pay service charge but each year major fund contributions.
I’ve had enough now and considering legal
Action against the freehold company.
Didn’t go down insurance route perhaps I should have? Is it too late.
Thx