A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
Getting a double-storey extension right in Sandown starts with understanding the house you already have: its age, how it was built and what has been altered over the years. We survey first, then commit on paper to a price that holds as long as the scope stays the same. Across the South East, guide prices run at £67,000–£134,000 including VAT, and homes in Ryde, Newport, Isle of Wight and Southsea are covered too.
- Guide price
- £67,000–£134,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- PO36
- Planning rules
- England
- Local area
- Isle of Wight
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Sandown?
The table below shows guide prices for a double-storey extension in Sandown. They are based on rates in the South East, which run about 12% above the national guide, giving an overall range of £67,000–£134,000. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Sandown |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £45,000–£73,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £67,000–£134,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £112,000–£202,000 |
The main things that change the figure:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What does the job include in Sandown?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Homes in Isle of Wight
The island has Victorian seaside villas and terraces in Ryde, Ventnor, Shanklin and Cowes, older cottages in island sandstone and limestone, and thatched roofs in some villages. Post-war bungalows, chalets and newer estates are common around Newport and the larger towns.
Salt and wind exposure is high on most coasts, and parts of the south, such as the Undercliff near Ventnor, are known for ground movement.
With that background in mind, here is how we typically handle a double-storey extension for homes in Sandown, from the first visit to the finished result.
Do you need permission in Sandown?
The notes below cover England, which is where Sandown sits. Rules change and every property is different, so we speak to the council before pricing your job.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
A visit to your home
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a double-storey extension.
Quote in writing
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Plan and prepare
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Sandown property.
Finish and handover
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
Working with SK Home Improvements
Common questions
Can you combine a double-storey extension with other work?
Yes. Because we manage several trades under one contract, we can plan a double-storey extension alongside other work on your Sandown home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
Do I need planning permission in Sandown?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Sandown is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Also covering areas around Sandown
Live in Sandown? Our coverage takes in the PO36 postcode areas and reaches out to Ryde, Newport, Isle of Wight and Southsea, so homes on the outskirts and in the next town along are included.