Securing Prior Approval for a Larger Rear Extension in Billericay
How a larger home extension prior approval was secured for an 8m single-storey rear extension in Billericay, and the key requirements every homeowner needs to meet.
PRIOR APPROVAL SUCCESSESBASILDONESSEX
Andrew Ransome
7/23/20264 min read
In 2026, I acted as agent for the homeowner at Crystal, Broomhills Chase, Billericay, in securing prior approval for a substantial single-storey rear extension under the Larger Home Extension permitted development scheme. The proposal projected a full 8 metres from the rear wall of the original dwelling, with a maximum height of 4 metres and an eaves height of 2.4 metres, finished in materials to match the existing house. Basildon Council granted prior approval, allowing the extension to proceed without the need for a full planning application.
This case is a good illustration of how the larger home extension route can unlock significant additional floor space quickly and with far greater certainty than a conventional application, provided the scheme is designed correctly against the technical limits from the outset.
Why the Larger Home Extension Route
Permitted development rights under Part 1, Class A of Schedule 2 to the Town and Country Planning (General Permitted Development) Order 2015 (as amended) allow householders to extend without planning permission, subject to strict size limits. For a standard single-storey rear extension, those limits are 4 metres for a detached house and 3 metres for any other type of dwelling.
The Larger Home Extension scheme, introduced as a separate prior approval route and since made a permanent part of the GPDO, extends those limits considerably: up to 8 metres for a detached dwelling and 6 metres for a semi-detached or terraced dwelling. Crucially, this larger scale of development does not require a full planning application. Instead, it is assessed through a prior approval and neighbour consultation procedure, which is faster and more predictable, provided the scheme meets the qualifying conditions.
At Crystal, the client wanted to maximise rear floor space for a kitchen and family living extension. An 8 metre single-storey extension of this kind would have needed full planning permission under the standard permitted development limits, with the delay and uncertainty that brings. Structuring the scheme to qualify under the larger home extension provisions instead meant the difference between a six to eight week prior approval process and a much longer application timetable with no guarantee of the same design being acceptable.
The Key Requirements
Getting a larger home extension through prior approval depends on meeting a specific set of technical and procedural requirements, all of which were addressed in this scheme:
Single storey only. The extension must not exceed one storey, and this was reflected throughout the drawings submitted.
Depth limit for the dwelling type. As Crystal is a detached property, the maximum permitted depth is 8 metres from the rear wall of the original house. The scheme was designed to sit exactly within that limit.
Maximum overall height of 4 metres. The proposed extension's ridge height was kept within this ceiling.
Eaves height controlled near boundaries. Where an extension is within 2 metres of a boundary, its eaves height is capped at 3 metres. The scheme's 2.4 metre eaves height comfortably satisfied this, allowing the extension to sit close to the boundary without difficulty.
Materials to match the existing dwelling. The GPDO requires that materials used in any permitted development extension be similar in appearance to those of the existing house. This was confirmed on the application form and reflected in the supporting drawings.
No exceedance of other Part 1 limits. The extension had to be checked against the wider permitted development rules, including the amount of curtilage that can be covered and confirmation that no previous extensions had already used up the homeowner's permitted development allowance.
The site not on excluded designated land. The Larger Home Extension scheme does not extend to certain forms of designated land, so an early check confirmed the property fell outside any Conservation Area, Article 2(3) land, or similar designation that would have ruled the route out.
The Neighbour Consultation Procedure
Unlike a standard planning application, a larger home extension prior approval is determined through a neighbour consultation scheme. Once submitted, the Local Planning Authority must notify the owners or occupiers of any adjoining properties and give them 21 days to raise objections relating specifically to the impact of the proposed extension on the amenity of their property.
If no objections are received within that period, or if any objections received do not, in the authority's view, justify refusal, the authority must grant prior approval. If the authority fails to notify a decision within 42 days of validation, the development is treated as approved by default. In this case, the application was properly notified to the neighbouring occupiers, no objection was raised that altered the outcome, and Basildon Council formally granted prior approval within the statutory period.
The Lesson for Homeowners and Developers
The value of the larger home extension route lies in matching the scheme to the rules precisely rather than treating the technical limits as a rough guide. An extension that strays even slightly over 8 metres, or an eaves height that creeps above 3 metres near a boundary, falls outside the scheme entirely and reverts to needing full planning permission, with all the delay that involves.
For anyone considering a substantial single-storey rear extension, the message from this case is straightforward: get the numbers right at the design stage, confirm the property qualifies before submission, and the larger home extension route can deliver a significant increase in living space with a far shorter and more certain path to approval than a conventional planning application.
Planning Application Advice
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Andrew Ransome MRTPI - Email: andrew@andrewransome.co.uk
About me
Andrew Ransome is a Planning Director and a Chartered Member of the Royal Town Planning Institute (RTPI), with more than two decades of experience in town planning.
He specialises in delivering strategic planning solutions for complex developments across both rural and urban environments, helping clients navigate planning challenges and unlock development opportunities. Connect with Andrew on Linkedin.
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Get in touch for planning advice: Email: andrew@andrewransome.co.uk
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