Part single, part two-storey extensions in Newport Pagnell

Quick reference for homeowners in Newport Pagnell.

Postcode districts: MK16 and MK46
County / area: Buckinghamshire, England
Price region: South East England
Guide price: £79,000–£109,000 (£2,200–£3,030 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Milton Keynes (3.5 miles), Bletchley (6.5 miles), Kempston Hardwick (9.5 miles)
Distance to Milton Keynes: about 3.5 miles
First visit: Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

We cover postcode districts MK16 and MK46 in and around Newport Pagnell, along with neighbouring Milton Keynes, Bletchley and Kempston Hardwick.

What it costs in Newport Pagnell

A guide price for Newport Pagnell: around £79,000–£109,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). That works out at £2,200–£3,030 per m² of new floor space, including VAT at 20%. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

Spec	Per m²	A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential	£2,020–£2,780 per m²	£73,000–£100,000
Standard	£2,200–£3,030 per m²	£79,000–£109,000
Premium	£2,640–£3,630 per m²	£95,000–£130,500

Planning and building regulations in Newport Pagnell

In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need planning permission, costing £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Newport Pagnell homes

The roof junction

Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.

Structure at the step

The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.

How we'd run your project

Free site visit
We visit your home in Newport Pagnell, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about part single, part two-storey extensions in Newport Pagnell

Which postcodes do you cover around Newport Pagnell?

We cover Newport Pagnell (MK16 and MK46) and nearby places including Milton Keynes, Bletchley and Kempston Hardwick, plus the rest of Buckinghamshire. The first site visit is free.

Who handles building regulations for a project in Newport Pagnell?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Do I need planning permission for a part single, part two-storey extension in Newport Pagnell?

Newport Pagnell is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Can the single-storey part be deeper than the two-storey part?

With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Nearby

Nearby towns we cover for part single, part two-storey extensions:

Other extensions in Newport Pagnell

All two-storey extension services in Newport Pagnell · Part single, part two-storey extensions across Buckinghamshire

The quickest next step is a visit. We'll look at your house in Newport Pagnell and give you an honest view of the options.