Part single, part two-storey extensions in East Cowes
Want to stay in East Cowes but need more space? A part single, part two-storey extension adds floor area on two levels without giving up much garden. Here's what's involved.
We take on projects in East Cowes by arrangement. Site visits here aren't free as standard, and we'll agree travel costs with you in writing first.
Before you start in East Cowes, here's what applies.
- Postcode districts
- PO32
- 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
- Cowes (0.5 miles), Newport (Isle of Wight) (3.9 miles), Ryde (5.8 miles)
- Distance to Newport (Isle of Wight)
- about 3.9 miles
- First visit
- By arrangement
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 postcode district PO32 in and around East Cowes, along with neighbouring Cowes, Newport (Isle of Wight) and Ryde.
What it costs in East Cowes
In South East England, which includes East Cowes, 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. Professional fees for drawings and the structural engineer are listed separately 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 East Cowes
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 East Cowes 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 East Cowes and any travel costs with you in writing first, then look at the structure, access and boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering East Cowes.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about part single, part two-storey extensions in East Cowes
How much does a part single, part two-storey extension cost in East Cowes?
Our guide for South East England, which covers East Cowes, is £2,200–£3,030 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £79,000–£109,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Do I need planning permission for a part single, part two-storey extension in East Cowes?
East Cowes 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 East Cowes?
We cover East Cowes (PO32) and nearby places including Cowes, Newport (Isle of Wight) and Ryde, plus the rest of the Isle of Wight. Visits and projects in East Cowes 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
Other towns near East Cowes:
Other extensions in East Cowes
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in East Cowes · 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 East Cowes.