How long does planning permission last?

[Mehaveit]

If a house got permission for a 2 storey extension in 90s but only the ground floor bit was built, could the second storey bit be done (foundations permitted) without further permission? The extension exceeds the 3m permitted development rules in place at the moment.

Do you live in a terrace or could the second storey have any perceivable impact on a neighbour?

I'm not sure how it relates to planning permission but I'm pretty sure the buildings regs inspections happen at various points in the build so they may not be possible so late after the initial part.

Usually if a start has been made, the PP is still valid. However, check the rules with LA Planning department. The difficulty is that guidelines might have changed so they might be able to ask you to redesign to meet current guidelines and policies. It is best to check.

If no stgart is made, it is usually 3 years from PP being granted.

It's a detached bungalow with a single storey extension and currently no additional room in the loft as per plans.

If the extension was started the permission would still be valid and extant. You could apply for a certificate of proposed development which would allow you to officially confirm this with the Council.

Zarara thank you