01Planning
Prior approval for a deeper London rear extension
Prior approval is the middle road between a 3 m permitted extension and a full planning application: you may go to 6 m on a terrace or 8 m on a detached house, if the council does not object to the neighbours' side of the story. We survey, draw and submit it. From £715, fixed before we start.
From £715 inc survey (£515 if you supply measured drawings)
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02The fee
One fixed fee, published
Prior approval (larger home extension)
from £715
inc survey (£515 if you supply measured drawings). No VAT to add.
Ask for your fixed feeWhat you get
- Our measured survey of the house and the neighbours' rear windows, part of the fee shown
- A written check that the house qualifies: not a flat, not in a conservation area
- The written description, site plan and addresses the Order says must accompany the notice
- Plans and elevations showing depth, height and eaves against each limit
- Submission to the council and replies to the officer, with no extra fee from us
- A free redraw if the officer asks for a lesser depth
The council's prior approval fee of £249 is paid to the council, not to us. Our fee carries no VAT to add.
03How it runs
How a larger-home notification runs
6 m / 8 m
Greatest depth of a single-storey rear extension under the larger-home route, attached and detached houses. Source: legislation.gov.uk
04Planning
What the route allows, and what it excludes
Under the larger-home rules a single-storey rear extension may reach 6 m on an attached house and 8 m on a detached one, up to 4 m high. The route is shut on land such as a conservation area and on a site of special scientific interest, and it is not open to flats at all.
Because the depth is double what you could build without asking, the neighbours get a say. The council writes to the adjoining owners, who have at least 21 days to comment; if none object, the council's job is shorter, but where one does it must weigh the harm to their amenity before it decides.
05Planning
Silence is consent, but only after 42 days
If the council has not told you its decision within 42 days of receiving your information, the extension may be started. That is the sharpest difference from a planning application, and the reason the paperwork must be complete on the first day: an incomplete notice stops the clock.
The Order lists what has to go in: a written description with the depth beyond the rear wall, the maximum height and the eaves height, a site plan, the addresses of the adjoining premises and your contact address. We draw to that list and add the sections an officer will want to see, so the case reads in one sitting.
06Planning
Prior approval or a planning application?
The choice is a trade of depth against certainty. A notification is cheaper in the council's fee and quicker, but it can only be granted or refused on one narrow ground. A full planning application takes eight weeks, costs the larger fee and lets you argue the whole design, which suits an extension that is deeper still or where the house sits in a conservation area.
For a modest increase over the 3 m limit, say another metre, a Lawful Development Certificate may be the better route because no neighbour consultation is needed. We compare the three in writing before we quote.
07The record
Figures that shape the job
6 m / 8 m
Greatest depth of a single-storey rear extension under the larger-home route, attached and detached houses.
Source: General Permitted Development Order 2015, Schedule 2, Part 1, Class A, checked 15 Oct 2026
42 days
Wait after which development may begin if the council has not notified a decision.
Source: General Permitted Development Order 2015, Schedule 2, Part 1, paragraph A.4, checked 15 Oct 2026
21 days
Least time the council gives adjoining owners and occupiers to send in representations.
Source: General Permitted Development Order 2015, Schedule 2, Part 1, paragraph A.4, checked 15 Oct 2026
£249
What the council charges for a larger-home extension notification, in force from 1 April 2026.
Source: Ribble Valley Borough Council, national fee table from 1 April 2026, checked 17 Oct 2026
4 m
Greatest height of a single-storey rear extension under the prior approval route.
Source: General Permitted Development Order 2015, Schedule 2, Part 1, paragraph A.1, checked 15 Oct 2026
No flats
Householder permitted development does not apply to flats or to buildings that contain flats.
Source: General Permitted Development Order 2015, article 2, checked 15 Oct 2026
£548
National householder planning fee, the alternative if the notification route is closed.
Source: Ribble Valley Borough Council, national fee table from 1 April 2026, checked 17 Oct 2026
08Questions
What clients ask before they instruct us
Is prior approval available in a conservation area?
No. The larger-home route does not apply on land such as a conservation area, so an extension there needs a householder planning application. We check that before we quote, and say so in writing.
What happens if a neighbour objects?
The council must weigh the effect on that neighbour's amenity, such as light and outlook, before deciding. We draw the flank and eaves with the neighbour's windows in mind, so an objection has little to attach to.
Can I start work after 42 days of silence?
Yes: development may begin if the council has not given its decision by then. We would still keep a dated copy of the submission, because a lender or buyer may later ask for it.
How much do you charge?
From £715 with the survey included, fixed in writing, and with no VAT to add. The council's own fee is separate.
Does it cover the building regulations too?
Not by itself. Prior approval is a planning matter, and the extension still needs building regulations drawings, which we can prepare from the same model.
09Related
Related services and guides
Send us the address of your house.
We look up the conservation area, listing and Article 4 position, then reply with a fixed fee. A message before 3pm is answered the same working day.