BigBub

Each council will have its own published Enforcement Policy and most take the view that proportionate action in relation to a proven breach of planning would only be taken where there is demonstrable harm caused and where it is expedient to do so. Whilst it is unlikely the council would even be made aware of a discrepancy less than 100mm, its also unlikely they would take any action over it as it would be considered de minimus. At most, you may be asked to submit a variation of condition to amend the approved plans, and at worst the changes could be considered material differences which negate commencement of the development and could lead to planning permission being lost.

I have encountered LPAs that outright refuse to accept electronic applications unless they come via the Planning Portal, although they are legally required to register the applications sent directly via email. Many councils have set administration/validation fees in addition to the planning application fee to deter submissions other than via the Planning Portal. The LPAs know this is likely unlawful but how many developers are going to argue over £50 and cause unnecessary delays to their application, possibly having to appeal for non-determination? There has also been a recent appeal where the appellant hadn't fully paid an added administration fee with their application and the inspector did not consider the council's fee necessary for validation and determination of the application.

Have a look at your council's Statement of Community Involvement (SCI) and see if it says anything around notice for committee or reasonable adjustments that could allow committee to be postponed.

Sorry, you're right on this. Would likely fall under self-build exemption

Something to think about is any new requirements for Biodiversity Net Gain (BNG) which weren't required back in 2020 but would now apply to any new proposal you might submit.

You may be able to get permission for the proposed extension but the council would be very unlikely to agree to the extension going right up to the boundary line. The guidelines typically expect 1-2m separation to avoid the terracing effect. It may therefore not be worth doing based on the amount of space you would gain.

At a minimum, your prior approval application would have required a block plan to be included showing the proposed extension. Block plans are top-down views and usually show the largest outline of your proposal which should have been the roof with the overhang. The tech guidance carries limited weight compared to the regs. The regs use the wording "the enlarged part of the dwellinghouse would have a single storey and extend beyond the rear wall of the original dwellinghouse..." so I think it is fair for this to include large overhangs. You can no longer rely on the prior approval and therefore must make a retrospective householder planning application. No merit in requesting a different planning officer.

Look in to the Principle of Consistency: https://www.tpexpert.org/plannings-ultimate-curse/ "The principle is not that like cases must be determined alike, but a decision-taker ought, when considering a materially similar proposal, to have regard to the principle of consistency, to have good reason if deciding to depart from the previous decision, and to give reasons for any such departure." It doesn't necessarily mean you would be successful with an appeal but it would put the onus on the council to justify why they changed their view on the extension being overbearing/overshadowing.

Other than outline permission, you could also consider the Permission in Principle (PIP) route as this only requires an application form, site location plan and fee.

I would take it to appeal if I was you. Certificates of Lawful Development for existing development are made under Section 191 of the Town and Country Planning Act 1990 which defines lawful development as development against which no enforcement action may be taken and where no enforcement notice is in force, or, for which planning permission is not required . (refer to https://www.gov.uk/guidance/lawful-development-certificates#definition-of-lawfulness-and-its-limits) It might depend on how you made your CLD application though with the wording you used and the land you outlined in red compared with your application.

Your council will have a Statement of Community Involvement somewhere on their webpages. This document usually sets out the policy for the minimum number of objections that will bring an application to committee. Otherwise it could be that someone has asked a local Councillor to call the application in for committee.

Is the annexe being built under Permitted Development or Planning Permission?

When a council can no longer demonstrate a five-year housing supply, the tilted balance is engaged. This usually leads to more housing applications for the council which may not accord with every policy in their local plan but more weight may be given to them in meeting the housing need on balance. https://www.savills.co.uk/blog/article/312988/residential-property/in-plain-english--the-tilted-balance.aspx

Given that you have agreed to the extension of time to the deadline you also won't have the benefit of getting your fee refunded for the extra delay...

It would likely be much cheaper to use your local authority's pre-app service compared to the £1,000 appraisal