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.
From a first conversation about a double-storey extension to the day the site is cleared, homeowners in Musselburgh deal with us directly. We come out to measure up at no cost, explain the choices in plain terms and send a written quote. For context, comparable work in Scotland usually falls within £58,000–£115,000 including VAT, and it is available across EH21.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- EH21
- Planning rules
- Scotland
- Local area
- East Lothian
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Musselburgh?
Below is a breakdown of typical costs for a double-storey extension in Musselburgh. Because rates in Scotland are about 4% below the national guide, the overall guide comes to £58,000–£115,000, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in Musselburgh |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,500–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £58,000–£115,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £96,000–£173,000 |
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
Scope of the work
- 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
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
Local housing and a double-storey extension
Edinburgh's New Town is a planned Georgian sandstone townscape within a World Heritage Site, and districts such as Marchmont and Leith have Victorian tenements. Bungalows and villas fill the suburbs, Midlothian has former mining villages, Livingston was built as a new town, and East Lothian villages often have red pantile roofs.
Listed and conservation-area homes need careful window and stone repairs. Bungalows commonly suit loft conversions and dormers, and suburban semis take extensions and garage conversions.
In Musselburgh, as elsewhere in Edinburgh and the Lothians, we take the building's age and construction into account before recommending anything, because both can change what is involved in a double-storey extension.
Planning and building rules in Musselburgh
Which rules apply depends on where you live. For Musselburgh, the answer is Scotland, and the points below reflect that; we verify them with the council before quoting.
In Scotland, extensions of more than one storey are only permitted development in narrow cases (Class 1B, well away from the boundary they face and outside conservation areas), so most need planning permission.
A building warrant is required before work starts. Scotland has no Party Wall Act; neighbour and title issues are handled under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
Survey and measure
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Price and scope agreed
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
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a double-storey extension are in place before the first day on site.
On site to finish
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.
Why homeowners choose us
Frequently asked questions
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.
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.
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.
How much does a double-storey extension cost?
A typical double-storey extension of 30–40m² across both floors costs £58,000–£115,000, built to a plastered finish. As a rough guide, allow around £1,400–£2,600 per square metre plus fixed costs for groundworks, scaffolding and fees. The second storey usually costs less per square metre than the first, because foundations and roof are shared. Bathrooms upstairs and a complex roof add most. We confirm a fixed price after the survey.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Near Musselburgh
Our coverage in Musselburgh includes EH21. We also travel to Bonnyrigg, Edinburgh and Penicuik, so neighbouring addresses are looked after on exactly the same terms as those in town.

