Why planning applications are returned as invalid

Most invalid planning application reasons have nothing to do with whether your extension is acceptable. They are administrative: a box left blank, a drawing without a scale bar, an ownership certificate unsigned, a fee short by a few pounds, or a document the council's local list asked for that you did not know existed. The council will not consider the merits at all until the application is valid, and the eight week clock does not start until it is.

Drafted documents help with some of this and cannot help with any of the rest. A well structured supporting statement will not rescue an application whose location plan is at the wrong scale.

What validation actually tests

Validation is a completeness check against two lists.

The national requirements apply everywhere and come from section 62 of the Town and Country Planning Act 1990 and article 7 of the Town and Country Planning (Development Management Procedure) (England) Order 2015. They cover the standard application form fully completed, a plan identifying the land, the ownership and agricultural holdings certificates, a design and access statement where one is required, and the correct fee.

The local list is the council's own published set of additional requirements, and it varies between authorities. It has to be published on the council's website and kept up to date, and an item can only be insisted on where it appears on that published list and is reasonable and material to the application.

What validation does not test is quality. A validation officer does not assess whether your heritage argument is persuasive, only whether a heritage statement was provided where the local list asked for one.

Form errors that stop an application

The form is where most returns originate, and the same fields recur.

• The description of development, which has to describe what you are applying for accurately and match the drawings
• The site address and postcode, which must match the red line on the plan
• Pre-application advice, where the reference has to be given if you had any
• Trees: a yes answer on trees on or adjacent to the site with no tree information supplied
• Parking: the existing and proposed space counts left blank
• Foul and surface water drainage, where a blank or an inconsistent answer generates a query
• The ownership certificate, unsigned, undated, or the wrong certificate for the facts
• The declaration, unsigned

Two of these deserve particular care. The description of development becomes the definition of what is permitted if consent is granted, so a description that omits the rooflights you have drawn will cause problems later. And the ownership certificate is a statement of fact with legal consequences, so if anyone other than you owns any part of the land, including a shared driveway or a strip of verge, the certificate changes.

Drawings, scales and the north point

Councils return more applications for drawing defects than for anything else, and the requirements are mechanical.

A location plan needs to identify the land at a scale that shows the surrounding area, normally 1:1250 in a built-up area or 1:2500 for a larger or rural site, with the application site outlined in red and any other land the applicant owns nearby outlined in blue. A block or site plan, usually at 1:200 or 1:500, shows the site in detail with boundaries, the building footprint and the position of the works.

Existing and proposed floor plans and elevations come at 1:50 or 1:100. Every drawing needs a unique drawing number, a revision, a scale bar, a stated scale, and a north point on the plan views. Printed at the stated scale, the dimensions have to measure correctly.

Three errors that come back regularly. Drawings marked "not to scale", which cannot be validated. A location plan with no red line, or a red line that omits the access. And existing drawings that do not match what is on the ground, which is not strictly a validation matter but generates the same delay once the officer visits.

Missing documents from the local list

This is the requirement people do not see coming, because it is specific to the council.

Common local list items on householder work include a heritage statement in a conservation area or for work to a listed building, tree information where trees are on or near the site, a flood risk assessment in Flood Zone 2 or 3, a biodiversity or ecology statement, a parking or access plan, and sometimes a daylight and sunlight assessment where the extension is close to a boundary. The question of when the last of those is expected is covered in the article on when a daylight and sunlight assessment is required.

Find the local list before you submit. It is on the council's planning pages, usually titled local validation requirements or local information requirements, and it will say which items apply to which type of application.

Where a document is needed, provide the document rather than a promise of it. An application submitted with a note saying a survey will follow is not valid, and the council will hold it as invalid until the survey arrives.

Fees and exemptions claimed wrongly

Fees are set nationally by regulations and are indexed, so the amount changes. Check the current fee schedule on the day you submit rather than relying on a figure from a previous project.

Two exemptions cause trouble on householder work. The first is the exemption for works designed to improve access or safety for a disabled person, which is specific in scope and is not a general reduction for accessibility improvements. The second is the free-go provision, which allows one further application for development of the same character on the same site within 12 months of a decision or withdrawal, subject to conditions in the regulations. Claim either wrongly and the application is underpaid, which means invalid.

An underpayment of a few pounds stops the application as effectively as a missing drawing. Pay the amount the council's own fee calculator produces, and if the figure looks wrong, ask before submitting. The article on the cost of failing validation and resubmitting sets out what these delays actually cost.

Responding to an invalidity notice

The council will write listing what is missing. Read the list against the published local requirements before doing anything else.

If the items are national requirements, supply them. There is no argument to have.

If an item is on the local list and applies to your application, supply it. If an item is not on the published list, or the list does not apply it to an application of this type, reply in writing saying so, quote the list, and ask the validation officer to reconsider. Most of these are resolved at that point, because the request was a default rather than a decision.

There is no right of appeal against a refusal to validate. The routes if a council holds an unreasonable position are to supply the item under protest, to use the council's formal complaints procedure, or in rare cases to seek judicial review. None of those is quick, which is why getting the submission right first time matters more here than almost anywhere else in the process.

Where a drafted document is what is missing, it can be produced quickly, and a Planning Statement or heritage statement drafted and then reviewed is usually the fastest route back to validation. Close out every flagged gap in the draft before submitting, because a placeholder left in a submitted document invites a second look at everything else.

The effect on the determination date

The determination period runs from the day after the council receives a valid application, not from the day you pressed submit.

For a householder application that period is eight weeks. An application submitted on 1 March and validated on 22 March is decided by reference to the later date, so three weeks of invalidity is three weeks of delay, and there is no mechanism to recover it.

Council closures compress this further at certain times of year, which the article on council closures at Christmas and determination periods covers.

So the practical advice is dull and effective. Download the council's local list. Check the fee on the day. Print one drawing at the stated scale and measure it. Read the form once more before signing the declaration. The article on where drafting saves time on a householder application covers the parts of the work where a draft does shorten the process, which is the narrative documents rather than the paperwork.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.