Hello,
Many thanks for your email,
Having handles does affect if your windows are compatible with the perfect fit blinds,
Please refer to our measuring guide (https://www.blindsbypost.co.uk/measuring-guides#perfect-fit-blind)
Where this advises how to check your clearances including clearance of window handles as this is 25mm clearance required around the frame and handle for the frame to be able to fit around the window as if not the blinds will not fit and would not be compatible,
If required you can purchase one of our sample kits that come with a piece of frame and bracket for you to physically try in your window to ensure this will fit around all sides and check handle clearances,
And also to check the clearance to ensure when you use the handle this does not hit the blind when you open and close, ,
If this does hit when you open and close the handle though you can purchase handle spacers to clear the frame from the handle ,
Please find link below to handle spacer and sample kit,