Does it say it has to be started or finished in 6 months?
Could always build a small part of it

It say's work has to start 2 years from the approval date of 10th May 2021 so May 2023, Starting before then is proving difficult.

There isn't an official definition of starting. If there in no extra clarification on the approval then I'd look to do some kind of minimum you can that could count as starting. I doubt it'll be an issue if you are planning on properly starting soon, just if you are selling with approved plans.

^ this. A place near our old place was due a massive renovation, funding started looking ropey but the planning was due to lapse, so they removed two fence panels and then did nothing for, well, ages. I don't know if they've even started yet, we moved out 18 months ago...

depends what defining "start" is - dig a couple of trenches as the start of foundations? easy to achieve, just get anyone in to start, couple of hundred quid, and if they need redoing after, thats ok

It's for my brother so I'll pass on the above advice, because I'm a mechanical design engineer he thinks I'm an expert in all things planning, if only !!!!

with six months to go you could reapply, Planning Officers I deal with take the view that the build could start so no objections raised by them.
other plan is to start the work,does the work involve any foundations? Local Authority I worked for as a Building Control officer the Planners would often come and ask if the works had started? the start would be a section of foundation, the Planning Applications would often be expiring in a week

"works in accordance with the permission" can be as little as a bit of a trench or two for footings, service runs or if you're really lucky and the permission requires (and includes in the description) demolition of an existing outbuilding etc you might be able to argue doing that constituted commencement.........but also need to be mindful that commencement won't trigger any CIL payments or similar that they'd also need to factor in

As above, 'spade in the ground' usually constitutes a start. So dig some foundation trenches, take photos and document it.

One project I'm aware of needed to do this. They dug a 500mm deep square of soil out of a field for a substation, 500m form the river where teh hydro-electric plant was going, took photos, filled it back in and teh council approved it as "works having commenced" and issued some form of legal document (not all councils issue this).

So yeah, dig a reasonable big bit of yor foundations, and get the plannere out/send them some pictures. It doesnt even need to be building regs compliant at this stage.

Ta
Keith

Local site here (in Calderdale) had service trenches dug and pipes/housing installed, then covered up again... looks like fields again now, with a few tell-tale access hatches. I had wondered why...

You need to have made a “significant start”. The scale of the work you’ll need to do to satisfy that requirement will depend on the scale of the original project.
You cannot extend planning permission, you’ll need to reapply if it expires. Shouldn’t be an issue unless planning policy has changed in the meantime!

I discussed it with him earlier and he now intends to make a start on the foundations and inform building control of this, I think to be belt and braces we can get a Certificate of Lawfulness, many thanks for all the above helpful advice

Make a start , seems to be the thing
I got sent out to put in some foundations on a project that was running out of PP it was some years ago now but still seems to be a thing may be a more expensive option than just reapplying?

Council I worked for, the planners looked for a positive inspection so digging 500mm where our minimum foundation depth was/is 1.0M wouldn't work . Submit the regs application and take it from there is my advice 🙂