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.
Every house in Norris Green is a little different, so we never price a double-storey extension from a brochure. We look at the structure, access and existing finishes first, then put in writing a fixed figure for the scope we settle on. As a rough steer, homeowners in the North West should budget £57,000–£114,000 including VAT, with work typically taking 14–22 weeks on site.
- Guide price
- £57,000–£114,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- L4, L9, L10, L11 and L12
- Planning rules
- England
- Local area
- Liverpool
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Norris Green?
Budgeting for a double-storey extension in Norris Green? The numbers below include VAT and are adjusted for the North West, where costs are about 5% below the national guide. The headline range is £57,000–£114,000. Nothing is final until we have measured up at a free survey and agreed the specification with you.
| Type of job | What it usually involves | Guide in Norris Green |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,000–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £57,000–£114,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £95,000–£171,000 |
Your price depends mostly on:
- 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 Norris Green?
- Groundworks, foundations and below-ground drainage
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Local housing and a double-storey extension
Liverpool's housing includes Georgian terraces near the centre, large areas of Victorian red-brick terraces, Edwardian semis in the suburbs and big interwar council estates. The Wirral has Victorian villas and interwar semis, Southport has Victorian villas and bungalows, and St Helens and Knowsley have post-war estates and newer housing.
Coastal areas on the Wirral and Sefton coast are exposed to salt and wind, and the region gets frequent rain off the Irish Sea.
That mix of housing shapes how we approach a double-storey extension in Norris Green: the age and construction of your home affect the materials, the method and, in the end, the price.
Do you need permission in Norris Green?
England, Wales, Scotland and Northern Ireland each handle planning a little differently. Norris Green comes under England, covered below, and we raise any questions with the council before your quote is finalised.
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.
The four stages
A visit to your home
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a double-storey extension so the price reflects your home.
Written quote
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Dates and permissions
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
The work itself
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
How we work
Double-storey extensions in Norris Green: questions
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.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Which postcodes in Norris Green do you cover?
We cover L4, L9, L10 and L11, along with the rest of Merseyside. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
Also covering areas around Norris Green
Live in Norris Green? Our coverage takes in the L4, L9, L10 and L11 postcode areas and reaches out to Kirkdale, Kirkby and Liverpool, so homes on the outskirts and in the next town along are included.

