Lytham St Annes · Lancashire

Part single, part two-storey extensions in Lytham St Annes

A part single, part two-storey extension is one of the most space-efficient ways to add bedrooms and living space to a house in Lytham St Annes, because the new floors share one set of foundations and one roof.

Lytham St Annes: the key facts for this kind of project.

Postcode districts
FY8
County / area
Lancashire, England
Price region
North West England
Guide price
£68,500–£94,000 (£1,900–£2,610 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
Blackpool (5.6 miles), Poulton-le-Fylde (6.3 miles), Southport (6.7 miles)
Distance to Preston
about 12 miles
First visit
Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension suits you if you want a generous ground floor but only need one extra room upstairs, or if a full two-storey design would affect a neighbour too much. You get design options that test where the two-storey part works best, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

We cover Lytham St Annes (FY8) and the places around it, including Blackpool (5.6 miles), Poulton-le-Fylde (6.3 miles) and Southport.

What it costs in Lytham St Annes

A guide price for Lytham St Annes: around £68,500–£94,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). That works out at £1,900–£2,610 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.

SpecPer m²A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential£1,750–£2,400 per m²£63,000–£86,500
Standard£1,900–£2,610 per m²£68,500–£94,000
Premium£2,280–£3,130 per m²£82,000–£113,000

Planning and building regulations in Lytham St Annes

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 Lytham St Annes homes

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.

Light into the kitchen

The single-storey part is the place for roof lights or a lantern, which bring daylight deep into the plan. In England, glazing is normally limited to 25% of the new floor area plus any windows removed, unless calculations show the house still performs, so we plan the balance early.

How we'd run your project

  1. Understand the brief

    At your home in Lytham St Annes we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Choose the approval route

    Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. Build and hand over

    We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about part single, part two-storey extensions in Lytham St Annes

Do I need planning permission for a part single, part two-storey extension in Lytham St Annes?

Lytham St Annes 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.

Which postcodes do you cover around Lytham St Annes?

We cover Lytham St Annes (FY8) and nearby places including Blackpool, Poulton-le-Fylde and Southport, plus the rest of Lancashire. The first site visit is free.

How long does a part single, part two-storey extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Can I add roof lights to the single-storey part?

Yes. Roof lights or a lantern over the single-storey part are one of the main reasons to choose this design, as they light the middle of a deep kitchen. In England they count towards the Part L glazing allowance, normally 25% of the new floor area plus windows removed, so we balance them with the rear doors.

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

We also cover places near Lytham St Annes, including:

Other extensions in Lytham St Annes

All two-storey extension services in Lytham St Annes · Part single, part two-storey extensions across Lancashire

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

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