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.
Thinking about a double-storey extension in Witham? We take charge of the whole project, co-ordinating every trade involved, and one person keeps you updated. Guide prices for the East of England sit at £63,000–£126,000 including VAT, and a typical job takes 14–22 weeks on site. Your own figure depends on what the survey finds and the specification you settle on.
- Guide price
- £63,000–£126,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- CM8
- Planning rules
- England
- Local area
- Essex
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Witham?
Prices for a double-storey extension vary from house to house, but in Witham most projects fall within £63,000–£126,000 including VAT. That reflects costs in the East of England, about 5% above the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Witham |
|---|---|---|
| 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 |
Expect these to shape the final quote:
- 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’s included?
- 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
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Witham
Essex ranges from timber-framed and weatherboarded cottages in the north, some with decorative pargeting, to Victorian terraces in Colchester, Chelmsford and Southend. Basildon and Harlow were built as post-war new towns, much of the south-east has interwar suburbs and bungalows, and large new estates continue to appear around Chelmsford and Braintree.
Essex is one of the driest counties in England, and London Clay in the south shrinks in dry spells, so trees and foundation depth matter.
Building traditions across Essex also raise conservation and planning questions, so we check those for a double-storey extension in Witham at the survey stage.
Planning and building rules in Witham
The notes below cover England, which is where Witham 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?
Free site survey
A free survey comes first. It gives us what we need to price a double-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Quote in writing
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.
Plan and prepare
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
Our trades complete a double-storey extension while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Working with SK Home Improvements
Common questions
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.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
Which postcodes in Witham do you cover?
We cover CM8, along with the rest of Essex. 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.
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.
Near Witham
We survey and quote throughout Witham's CM8 postcodes and in surrounding places such as Maldon, Braintree and Chelmsford. The process and pricing approach are identical in each of them.