Part single, part two-storey extensions in Freshwater
For a part single, part two-storey extension in Freshwater, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for the Isle of Wight.
We take on projects in Freshwater by arrangement. Site visits here aren't free as standard, and we'll agree travel costs with you in writing first.
Freshwater: the key facts for this kind of project.
- Postcode districts
- PO39, PO40 and PO41
- County / area
- The Isle of Wight, 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
- Newport (Isle of Wight) (10.4 miles), Cowes (11.4 miles), East Cowes (11.6 miles)
- Distance to Newport (Isle of Wight)
- about 10.4 miles
- First visit
- By arrangement
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.
Around Freshwater we also work in Newport (Isle of Wight), Cowes and East Cowes, and across the rest of the Isle of Wight. Postcode districts in and near Freshwater: PO39, PO40 and PO41.
What it costs in Freshwater
In South East England, which includes Freshwater, we'd expect a part single, part two-storey extension to cost 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), or £2,200–£3,030 per m² including VAT. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| 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 Freshwater
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 Freshwater homes
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.
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
Visit by arrangement
We agree a visit to your home in Freshwater and any travel costs with you in writing first, then look at the structure, access and boundaries.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.
Questions about part single, part two-storey extensions in Freshwater
Do I need planning permission for a part single, part two-storey extension in Freshwater?
Freshwater 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.
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.
Which postcodes do you cover around Freshwater?
We cover Freshwater (PO39, PO40 and PO41) and nearby places including Newport (Isle of Wight), Cowes and East Cowes, plus the rest of the Isle of Wight. Visits and projects in Freshwater are by arrangement, with travel costs agreed in writing first.
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.
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.
Nearby
The same service in neighbouring towns:
Other extensions in Freshwater
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Freshwater · Part single, part two-storey extensions across the Isle of Wight
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Freshwater.