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Can a flat window be converted to a bay window? what would be a general cost to have one changed ?

considering buying a hse which has a flat window at the front and wondered how costly t would be to change it to a bay window

3 Answers from MyBuilder Window & Door Fitters

Best Answer

Hi kaur8888

Yes you can convert the window to a bay, before any changes a survey would need to be carried out.
Remember structural safety if the replacement windows are wider than those they replace or support the upper floor.Bay windows now have reinforcement supports built in when required for support.

Use an installer registered under the FENSA scheme run by the Glass and Glazing federation, in which case you do not need to make a Building
Regulations application to the Council. Your FENSA installer should then ensure your windows comply fully with the regulations and will then register the installation with FENSA who will then supply you with a certificate confirming this when the installation is complete. If you wish to use this option please ensure that your installer is properly registered under the scheme before placing an order. You can check this and find more details of the scheme by visiting the FENSA website at

As for costs this depends on your requirements.

Hope this helps

Trevor & Mike


Answered 31st Dec 2011

You can change window to a bay, as for cost you need some one to measure up.
No one here can give a price with no dimensions or type of roof.


Answered 31st Dec 2011

CERTASS is same as FENSA too



Answered 3rd Jan 2012

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