Existing & Proposed Drawings for Planning Applications: What Your Local Authority Actually Needs

Most planning applications are delayed or rejected for the same avoidable reason: the submitted drawings don’t accurately represent the existing building, or the proposed changes aren’t clearly enough distinguished from what’s already there. Local planning authorities need to see exactly what exists now and exactly what’s proposed — and that starts with an accurate measured survey, not a rough sketch.

For homeowners, small developers and architects preparing a planning application across Hertfordshire, Essex, East Anglia and Cambridgeshire, here’s what existing and proposed drawings actually need to include, and why accuracy at this stage saves time later.

Survey boundary defined on a large commercial site in the East of England — control points established and verified before survey begins, producing the accurate existing condition data that local authorities require for planning applications. AKN Engineering carries out existing condition surveys for planning across Hertfordshire, Essex, East Anglia and Cambridgeshire.

What “existing” drawings need to show

Existing drawings are a measured record of the building and site as they currently stand — plans, elevations and sections drawn from an accurate survey, not estimated from memory or old drawings that may no longer reflect reality after previous alterations. Planning officers use these as the baseline against which every proposed change is judged, so any inaccuracy here undermines the whole application, regardless of how good the proposed design is.

What “proposed” drawings need to show

Proposed drawings show the building as it will be after the works — clearly distinguished from the existing structure so a planning officer can see exactly what’s changing, in what location, and by how much. Most local validation checklists require the extent of the proposed change to be unambiguous: new build clearly marked apart from retained structure, with dimensions and levels that can be checked against planning policy on things like height, massing and boundary distances.

Why accuracy at this stage matters more than it seems

An inaccurate existing survey creates a domino effect: the proposed drawings are measured against a baseline that’s wrong, planning officers may query the discrepancy (delaying validation), and if the application is approved on inaccurate drawings, the gap between drawing and reality can cause problems at building control stage or during construction. A properly measured existing survey, done once and done accurately, removes this risk entirely.

What local authorities are actually checking

Beyond the drawings looking professional, validation checklists typically require accurate scale, clear differentiation between existing and proposed work, correct north points and site boundaries, and dimensions sufficient to assess the application against relevant planning policy — things like distance to boundaries, height, and impact on neighbouring properties. Drawings that are vague or approximate on any of these are a common cause of applications being marked invalid before they’re even assessed on their merits.

Getting it right the first time

An accurate measured survey of the existing building and site, combined with clearly differentiated proposed drawings, gives an application the best possible chance of moving through validation without delay. It’s a relatively small cost against the time lost to a rejected or delayed application — particularly for homeowners and small developers working to a specific programme.

Working with AKN Engineering

AKN Engineering provides existing and proposed drawings for planning applications across Hertfordshire, Essex, East Anglia and Cambridgeshire, based on accurate measured surveys that give planning officers the clear, checkable baseline they need to validate an application without delay.

If you’re preparing a planning application and need accurate existing and proposed drawings, speak to AKN Engineering on 01279 927 033 or visit www.aknengineering.co.uk.