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 Perth 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 Scotland, guide prices run at £58,000–£115,000 including VAT, and homes in Auchterarder, Blairgowrie and Crieff are covered too.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- PH1 and PH2
- Planning rules
- Scotland
- Local area
- Perth and Kinross
- Survey
- Free, with a written quote
Double-storey extensions prices in Perth
What should you budget for a double-storey extension in Perth? Use the figures below as a starting point. Prices in Scotland sit about 4% below the national guide, so the range here is £58,000–£115,000 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Perth |
|---|---|---|
| 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 |
What moves the price up or down:
- 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
Scope of the work
- First-floor joists, stud walls and new openings upstairs
- 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
Local housing and a double-storey extension
Perth has Georgian terraces and Victorian sandstone villas, Highland Perthshire towns such as Pitlochry and Aberfeldy have stone villas and cottages, and Kinross and Crieff mix older stone housing with post-war and modern estates. Slate roofs and harled finishes are common in rural areas.
Sandstone villas in Perth and Highland Perthshire often need repointing and slate roof repairs, and many sit in conservation areas. Semis and newer homes commonly take extensions, garage conversions and garden landscaping.
With that background in mind, here is how we typically handle a double-storey extension for homes in Perth, from the first visit to the finished result.
Planning and building rules in Perth
For anyone in Perth, the relevant framework is Scotland's. The summary below is general, so we always contact the council about your address before putting a price in writing.
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.
How does the job run?
Free site survey
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.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
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.
Finish and handover
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
Frequently asked questions
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.
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.
How is the new roof joined to the existing house?
The new roof is usually tied into the existing roof so the two read as one. On a rear extension this often means a lower ridge or a hipped end, with valleys where the slopes meet. We strip back some existing tiles, fix new rafters and battens, and lay matching tiles or slates. Lead or proprietary flashings seal the junctions so water runs off properly.
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.
How much will a double-storey extension cost in Perth?
As a guide, expect to pay £58,000–£115,000 including VAT for a double-storey extension in Perth. That range is adjusted for Scotland, which runs about 4% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Nearby towns
Perth and its PH1 and PH2 postcodes are part of our coverage. Homeowners in Auchterarder, Blairgowrie and Crieff can also book a free survey with us and receive a written price for their job.