The new extension may be 20 m². The quotation also has to deal with the wall between it and the existing house.
Sweet Homes treats that junction as an early pricing check. The engineer may be designing steel, bearing details and temporary support where the kitchen, heating, floor levels and finishes meet the same wall.
Sweet Homes carries out extension construction as contractor. You appoint the architect, structural engineer and building-warrant professional. We price the approved drawings, specifications and measured property rather than deciding those professional roles ourselves.
Existing extension price bands
These are the bands already published by Sweet Homes for Edinburgh homeowners. The homeowner total including VAT comes first; the underlying plus-VAT band is kept in brackets.
| Typical scope | Indicative homeowner total |
|---|---|
| Side return, around 5–15 m² | £30,000–£54,000 including VAT (£25,000–£45,000 plus VAT) |
| Single-storey rear extension, around 15–25 m² | £42,000–£78,000 including VAT (£35,000–£65,000 plus VAT) |
| Kitchen extension with the kitchen work included | £54,000–£96,000 including VAT (£45,000–£80,000 plus VAT) |
| Two-storey rear or side extension, around 30–50 m² | £66,000–£120,000 including VAT (£55,000–£100,000 plus VAT) |
| Wrap-around extension, around 20–40 m² | £72,000–£132,000 including VAT (£60,000–£110,000 plus VAT) |
The current 20% standard VAT rate is used. These are indicative bands, not fixed prices. The written quotation is based on the measured property, approved information and selected specification.
A drainage diversion or the structural opening may be inside one construction price, carried as an allowance or excluded. On a kitchen extension, supply and installation can be separate even where two briefs use the same short description.
The existing house can move the price
A rear extension can meet old drainage, a change in floor level or services running through the wall that is coming out. Glazing and roof geometry are visible on the drawings. Existing finishes can still hide the service route.
The design team records the structural and approval information. Sweet Homes checks the build sequence and prices that information. A later drawing revision sends the affected construction line back for pricing.
Late client decisions can do the same thing without any change in the building. A kitchen ordered after the service positions were set, a revised door opening or an inaccurate product specification can alter work already coordinated. Damaged deliveries and one-off items from an untested supplier can hold up a small part of the job for longer than the fitting itself.
Planning and the building warrant
City of Edinburgh Council’s householder guidance says some small house extensions may be permitted development. It also records restrictions for flats, conservation areas and listed buildings, and points homeowners to a Certificate of Lawfulness where formal confirmation is wanted.
A building warrant is a separate route. Your appointed architect or warrant professional prepares that information and the verifier decides the application. Sweet Homes builds and prices against the resulting approved documents.
Reading two extension totals
Sweet Homes compares the inclusions and allowances against the design pack. The opening and the glazing are two places where a short description can hide a different scope. Professional and council fees can remain separate entries; ground and drainage may still depend on investigation or approved design.
For comparable ranges across other project types, see the Edinburgh renovation cost guide.
The Home Extensions Edinburgh page sets out the contractor scope and the same published bands.
Request a call with the property type, general area, proposed extension and any drawings already available. Send your enquiry by form or email. We will reply and arrange a follow-up call to talk through the project.
Compare the whole extension, not just the new floor area
A rate for the new floor area is only a starting point. An extension also needs a connection to the existing house. Opening the old wall, supporting the structure, matching floor levels and making good the rooms beside the opening can be a substantial part of the job. Two extensions with similar floor areas can therefore involve quite different work.
Separate the new structure from alterations inside the house when comparing proposals. Check whether the scope includes changes to the kitchen, heating, drainage and electrical installation, as well as finishes in the existing rooms. A lower headline figure is hard to interpret if those parts are missing.
Access, drainage and the existing building
Consider how materials reach the work and how excavated material leaves it. A direct route from the street is different from a narrow side passage or a route through the house. Storage space, protection and the sequence of deliveries belong in the plan rather than being left for the first day on site.
The drainage route and the connection to the existing building deserve early attention. Record what is known, what remains concealed and what further information is needed. Keep an allowance for unresolved work visible instead of treating it as a confirmed part of the price.
Foundations, a drainage diversion or the structural opening may be inside one construction price, carried as an allowance or excluded.
