The fast route to a deep single-storey rear extension in Olney — up to 6 metres on an attached house or 8 on a detached one — via Milton Keynes City Council's prior approval scheme rather than a full planning application.
Milton Keynes City Council granted 92% of the householder planning decisions it made in its latest published year — 1.7000000000000028 points above the 90.3% England-wide householder average. The Olney conservation area's Article 4 direction removes PD rights on all extensions, alterations, porches and exterior painting, so even minor works need consent, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837) and Victorian (1837–1901) housing stock sets the design brief on most streets.
The permitted-development ceilings are fixed: 40m³ of new roof volume for a terraced loft and 50m³ for a semi or detached house under Class B, plus a 3m single-storey rear extension on a terrace or 4m on a detached house under Class A. Olney carries at least one Article 4 direction, and conservation areas including Olney, Emberton and Clifton Reynes remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Olney is determined against an 8-week statutory target.
Olney (a Georgian market town on the Great Ouse, under an Article 4 conservation area), Emberton (a limestone village and conservation area south of the town), Clifton Reynes (a small riverside village and conservation area across the Ouse), Weston Underwood (a historic estate village and conservation area to the west), Lavendon (a stone-built village and conservation area on the road to Bedford) and Warrington (an outlying hamlet on the Ouse near Olney) — these are the Olney pockets our drawings cover most. Heritage designations here include Olney, Emberton, Clifton Reynes, Weston Underwood and Lavendon. Milton Keynes City Council weighs each proposal against Plan:MK (the Milton Keynes Local Plan 2019), where Olney sits in the rural north of the borough, well outside the New Town grid, with a listed Georgian core around the Market Place and church. On roofs the borough is pitched clay-tile, thatch and stone-slate roofs on the historic core and gabled roofs on the modern estates, over Georgian and Victorian market-town housing around the Market Place, limestone and brick cottages in the surrounding villages and later 20th-century estate housing on the town's edges.
The ordinary Class A limits stop a single-storey rear extension at 3 metres on an attached house and 4 on a detached one. The larger home extension scheme doubles both, on condition that the council is told first. That notification is not an application for permission — the council cannot refuse on design, materials or policy grounds. It can only consider the effect on the amenity of adjoining premises, and only if a neighbour actually objects during the 21-day consultation.
The other conditions still apply and are strict: single storey only, no higher than 4 metres, eaves no higher than the existing eaves, and no more than half the land around the original house covered. It is not available on designated land, so a house in a conservation area such as Olney and Emberton cannot use it at all. Materials must be similar to the existing house, and the extension must not include a veranda, balcony or raised platform.
Olney is largely Georgian and Victorian market-town housing around the Market Place, limestone and brick cottages in the surrounding villages and later 20th-century estate housing on the town's edges. The Olney conservation area's Article 4 direction removes PD rights on all extensions, alterations, porches and exterior painting, so even minor works need consent, which matters here because an objecting neighbour puts amenity squarely in front of a case officer. The Olney conservation area carries an Article 4 direction: all dwellinghouses lose permitted-development rights for any extensions or alterations, porches, and the painting of exterior walls — introduced to safeguard the Georgian market town's character.
The scheme is available where all of these hold. Fail any one and it is a full application to Milton Keynes City Council instead:
We prepare the notification pack Milton Keynes City Council needs — plans, elevations, a site plan with the adjoining owners identified — and manage the 21-day neighbour consultation so the 42-day clock is not restarted by an incomplete submission.
Below is Milton Keynes City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Milton Keynes approves the large majority of householder applications, but Olney's Article 4 direction and Georgian conservation-area character make it the borough's most tightly controlled market town. Prior approval turns on neighbour amenity alone, so the drawings that matter are the ones showing the relationship to the boundary.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
Tell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Across Olney, Emberton and Clifton Reynes, the notifications that clear without objection are the ones that treat the neighbour as the audience. We show the extension in section against the boundary, demonstrate the 45-degree daylight relationship to the nearest habitable window, and where the plot is tight we taper the depth away from the boundary rather than running the full 6 metres to the fence.
Olney sits in the rural north of the borough, well outside the New Town grid, with a listed Georgian core around the Market Place and church. Where an objection does arrive, the council's assessment is narrow: loss of light, outlook and overbearing effect on the adjoining property, nothing else. A pack that has already answered those three points on the drawings usually survives an objection, whereas one that leaves them to the officer's imagination usually does not.
We prepare prior-approval notifications across Olney. A few of the areas where deep rear extensions come up most often:
Prior approval drawings for Olney — a Georgian market town on the Great Ouse, under an Article 4 conservation area — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Prior approval drawings for Emberton — a limestone village and conservation area south of the town — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Prior approval drawings for Clifton Reynes — a small riverside village and conservation area across the Ouse — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Prior approval drawings for Weston Underwood — a historic estate village and conservation area to the west — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Prior approval drawings for Lavendon — a stone-built village and conservation area on the road to Bedford — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Prior approval drawings for Warrington — an outlying hamlet on the Ouse near Olney — dimensioned to the 6m and 8m limits and prepared for Milton Keynes City Council's neighbour consultation.
Same extension, two routes, very different tests.
| Route | Depth allowed | What the council may consider | Timescale |
|---|---|---|---|
| Ordinary Class A permitted development | 3m attached / 4m detached | Nothing — no application needed | Immediate |
| Larger home extension prior approval | 6m attached / 8m detached | Amenity of adjoining premises, only if a neighbour objects | 21-day consultation, 42-day determination |
| Full householder application | No fixed limit | Design, materials, policy, amenity, everything | 8-week target |
| Any of these on designated land | 3m / 4m only | Prior approval scheme unavailable | Full application beyond the limits |
Limits and procedure from the GPDO 2015, Schedule 2, Part 1, Class A and paragraph A.4, made permanent by amendment in 2019.
A process built around the 21-day consultation, which is where these schemes are won or lost.
Send us your Olney postcode and house type. We confirm whether the property is on designated land, whether the scheme is available, and what depth you can realistically take.
We measure the original rear wall, eaves height, boundary distances and the neighbouring windows that the amenity assessment will turn on.
We draw the extension to the 6m or 8m limit with the boundary relationship shown in section, and prepare the written description and adjoining-owner details Milton Keynes City Council needs to start the consultation.
We submit, track the 21-day consultation and the 42-day determination, respond to any objection on amenity grounds, and revise free until the decision.
Three metres on a terraced or semi-detached house and four on a detached one under ordinary permitted development. Under the larger home extension prior approval scheme those double to six and eight metres, provided you notify Milton Keynes City Council before starting and the conditions on height, materials and land coverage are met. The scheme is not available on designated land. This applies to your Olney address specifically.
It is a notification, not an application for permission. You tell Milton Keynes City Council what you intend to build, it writes to the adjoining owners, and they have 21 days to object. If nobody objects, you may build. If someone does, the council assesses the effect on the amenity of adjoining premises and must decide within 42 days. Design and policy are not in scope. This applies to your Olney address specifically.
The council then considers the impact on the amenity of the adjoining property — loss of light, loss of outlook, and overbearing effect — and nothing else. It cannot refuse because it dislikes the design or the materials. We prepare the drawings so those three questions are already answered in section and on the site plan, which is what usually carries an objected scheme through. This applies to your Olney address specifically. Milton Keynes City Council is the decision-maker.
No. The larger home extension scheme is unavailable on designated land, which includes conservation areas such as Olney and Emberton, national landscapes, national parks and world heritage sites. On those properties the ordinary 3-metre and 4-metre limits apply, and anything deeper needs a full householder application to Milton Keynes City Council.
Twenty-one days for the neighbour consultation, and a maximum of 42 days from a valid submission for the council to determine it. If the council does not respond within 42 days you may proceed as notified. That deadline is the scheme's real advantage over a full application, and it is why validation completeness matters so much. This applies to your Olney address specifically. Milton Keynes City Council is the decision-maker.
Yes — always. Prior approval deals only with the planning position. A 6-metre rear extension still needs building control approval for foundations, structure, drainage, thermal performance and fire safety, and the beam over the opening into the existing house needs designing and calculating. We prepare both sets so the notified scheme is the buildable one. This applies to your Olney address specifically. Milton Keynes City Council is the decision-maker.
We quote each Olney scheme individually, because plot shape and the boundary relationship drive the work, and send a fixed, no-obligation quote within one working day. It covers the notification pack and free revisions until Milton Keynes City Council determines it. Call 020 7864 7245 to start.
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Same fixed quotes, same fast drawings — wherever your project is.