How old is my rented flat?

I am half way through obtaining an insurance quotation, but they have asked when my flat was built.
Unfortunately, I do not have any details on the owner, and my letting agent is completely useless (I may aswell talk to a brick wall!).

Is there a website that can tell me when it was built?

I have tried using Google with the usual questions like:
When was my property built?
What year were properties in ________ built?
How old is my property?

Please can someone help me – my insurance options are severly limited without this information!

Thank you! x x x x x
Thank you Maisie,

I have tried the web address you have given, but I am receiving an error message: Internet Explorer cannot display the webpage.

I have tried to resolve the problems using Windows, but it cannot find a technical fault.