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 March 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 East of England, guide prices run at £63,000–£126,000 including VAT, and homes in Wisbech, Ely and Peterborough are covered too.
- Guide price
- £63,000–£126,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- PE15
- Planning rules
- England
- Local area
- Cambridgeshire
- Survey
- Free, with a written quote
Double-storey extensions prices in March
Here is how the guide price for a double-storey extension breaks down in March. We start from national figures and adjust for the East of England, which comes out about 5% above the national guide. The resulting range, VAT included, is £63,000–£126,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in March |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £42,000–£68,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £63,000–£126,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £105,000–£189,000 |
The main things that change the figure:
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What do you get?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Homes in Cambridgeshire
Cambridge has many Victorian terraces in pale gault brick, with Edwardian villas and modern estates around the city. Peterborough expanded as a new town from the 1970s, adding large planned estates, while Ely, Huntingdon, St Neots and the Fenland market towns keep Georgian and Victorian centres. Limestone appears in villages near the Northamptonshire border.
Narrow terraces commonly suit loft conversions and kitchen extensions. Newer estate homes often need garage conversions, porches and landscaping, and older brick and stone buildings may call for lime-based repointing and carefully specified windows.
That variety is why a guide price for a double-storey extension in March is only a starting point; the survey shows what your particular property needs.
Planning and building rules in March
The notes below cover England, which is where March 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.
What happens after you get in touch?
A visit to your home
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a double-storey extension, and photograph or measure anything the quote needs to reflect.
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.
Getting ready
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
The work itself
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
What you can expect from us
Double-storey extensions in March: questions
Which postcodes in March do you cover?
We cover PE15, along with the rest of Cambridgeshire. 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.
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 March 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.
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.
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 March
Whether you're in the centre of March or on its outskirts, PE15 addresses are covered. We extend the same service, and the same fixed-price approach, to Wisbech, Ely and Peterborough.