What is a double-storey extension?
A double-storey extension (also called a two-storey extension) adds rooms on both the ground and first floor in one build. It typically gives a larger kitchen or living space downstairs and an extra bedroom or bathroom above.
How much does a double-storey extension cost in Tayside?
In Tayside, a double-storey extension typically costs £1,600–£2,400 per m² of floor area (both floors), including VAT at 20% (standard rate). For a typical 36 m² project that is roughly £57,500–£86,500. Prices in Scotland sit near the national average for this kind of work, and the range for Tayside reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (25 m²) | £40,000–£60,000 |
| Typical project (36 m²) | £57,500–£86,500 |
| Larger project (50 m²) | £80,000–£120,000 |
| Rate per m² | £1,600–£2,400 |
The biggest cost drivers are:
- Roof design and how it joins the existing roof
- Scaffolding and access to the rear
- Brick matching and external finishes
- Bathrooms or en-suites on the first floor
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a double-storey extension in Tayside?
Here is how the rules work for a double-storey extension in Scotland. In Scotland an extension of more than one storey is only permitted development if it is at least 10 metres from every boundary and no higher than the existing ridge, so most need planning permission. A building warrant is needed before work starts.
Scotland has no Party Wall Act. Work on shared walls is governed by your title deeds, the Tenements (Scotland) Act 2004 for flats, and common law, so we agree arrangements with neighbours in writing before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Building control sign-off
- Brick or block walls, floors and a roof tied into the house
- Foundations, drainage and scaffolding
- Design drawings and planning application
- Windows, doors and staircase alterations
- Electrics, heating, plumbing and plastering
How long does it take?
The build itself usually takes 14 to 20 weeks on site, after planning and building control approval. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Tayside
In Scotland, bungalows and one-and-a-half-storey homes are common, so dormer conversions are a popular way to add bedrooms.
Towns we cover in Tayside include Dundee, Perth, Arbroath, Forfar and Montrose.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about double-storey extensions in Tayside
Do you build double-storey extensions in Tayside?
Yes. We build double-storey extensions across Tayside, including postcodes AB30, DD1, DD10, DD11 and DD2. Every project starts with a free home visit.
How much does a double-storey extension cost in Tayside?
In Tayside, a double-storey extension typically costs £1,600–£2,400 per m² of floor area (both floors), including VAT at 20% (standard rate). A typical 36 m² project comes to roughly £57,500–£86,500. Your fixed price depends on the survey and drawings.
What drawings do I need?
Planning drawings for the application, then more detailed building regulations drawings and structural calculations for building control. We prepare both.
Will the first floor need a new staircase?
Not normally. The new rooms are reached from the existing landing, though a doorway or short corridor may need to be formed.
Do I need planning permission for a double-storey extension in Tayside?
In Scotland an extension of more than one storey is only permitted development if it is at least 10 metres from every boundary and no higher than the existing ridge, so most need planning permission. A building warrant is needed before work starts.
Is a double-storey extension cheaper per square metre?
Usually yes. You pay for one set of foundations and one roof but get two floors of space, so the cost per square metre is often lower than a single-storey extension.