On this page
Prices shown as “from” are indicative starting amounts for the stated scope. Your quotation specifies materials, labour, VAT and additional work.
Price indications and what to compare
| Work | Indicative starting price | Scope and assumptions |
|---|---|---|
| Standard prefabricated extension, example 5 × 3 metres | From € 31,000 | Indicative market price. Check included items for each supplier and location. |
Market estimates consulted on 2 October 2026. These are not fixed Multi Concurrent rates. Your project quote specifies the price, VAT and included work.
Where can you make useful savings?
A rectangular floor plan and fewer changes of material reduce complicated details. Retaining existing service connections can limit pipework. Plan related work together and select finishes before construction starts.
Compare shell-only and fully finished options
A shell-only price may exclude much of the interior finish. Ask who will provide insulation, electrics, plastering, flooring, heating and painting. Once these are added, a lower shell price may exceed a complete quote.
Foundations remain project-specific
Ground conditions, the existing foundation and new loads determine the foundation design. A standard extension does not automatically have a standard foundation. The connection between the old and new buildings also needs to be designed.
Prefabrication or building on site
Prefabrication can reduce work on site where transport and lifting are feasible. Traditional construction offers flexibility for complex connections. The design, access and desired result determine the best choice.
From preparation to handover
Initial discussion
Discuss your requirements, intended use, address and budget.
Site survey
Assess the property, access and connections to the existing building.
Design
Agree the layout, natural light, appearance and materials.
Structural design
Design the foundations, opening and supporting structure.
Permits
Check the location and design through the Omgevingsloket.
Quote
Discuss the scope, provisional allowances, exclusions and price.
Preparation
Arrange the schedule, site logistics, deliveries and protection.
Foundations
Build the foundations in accordance with the project-specific design.
Shell structure
Construct the floors, walls, windows, doors and roof.
Installations
Coordinate electricity, water, heating and ventilation.
Finishing
Complete plastering, painting and floor finishes.
Handover
Inspect the work and agree how any outstanding items will be addressed.
Frequently asked questions
How do I compare a low-cost shell extension with a completed extension?
Compare both quotes against the same finished result. A shell quote may exclude services, flooring, plastering and painting. Include foundations, structural openings, waste removal and connections before choosing by total cost.
Where can I save without compromising the structure?
Discuss a simple shape, less bespoke work and a clearly defined finish. Choose materials early and avoid changes during construction. The required structure, weatherproofing and insulation must follow the design and the project requirements.
Is a prefabricated extension always the cheapest option?
No. Prefabrication, transport and lifting must suit the design and site access. Also compare foundations, the connection to the house and finishing work. A short installation period does not necessarily mean a lower overall project cost.
Is the price on this page a quote?
No. An estimate or worked example is for initial planning. The property, materials and agreed scope determine your quote.