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Costs and included work
For building an extension, compare the scope first: foundation, opening into the existing building, building envelope and finish level. A price is useful only when supply and finishing work are clearly defined.
| Work / price basis (from) | Starting indication | Scope |
|---|---|---|
| Extension: general budget indication | From € 2,200 per m² | Market indication; specify foundations, structure, finishes and VAT in the quotation. |
Market indications checked on 2 October 2026, not fixed Multi Concurrent tariffs. The stated work and unit apply; the quotation confirms the total, VAT and any additional work.
What affects your total?
Ground conditions, span, glazing, connections to the house and access determine the work. Kitchens, sanitary fittings, building services and interior finishes are included only when specified.
What to send with your request
Send dimensions, photos of the facade and garden, the proposed layout and available drawings. Include your postcode, preferred schedule and the elements that must remain, so the scope can be assessed.
Develop the layout
Consider daylight, circulation, furniture and connections to existing rooms. Discuss roof shape, openings and materials before fixing the dimensions. The design needs to work within the site and applicable requirements.
Prepare the project
Arrange the necessary survey, structural design and permission checks. Plan access, deliveries, temporary protection and any disruption to services. Agree which information is needed before work starts.
Build in sequence
Foundations and structural work precede weatherproofing, services and finishes. Coordinate the trades around the agreed design, and document changes before additional work is carried out.
Budget and handover
Compare a shell price with a fully finished room only after listing their differences. Include disposal, reinstatement and completion checks. The detailed extension guide explains the full sequence and links to cost information.