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How much does a house foundation cost in 2026: strips, piles or slab
The foundation is the one line in a quote that depends on your plot rather than on the design. On our SIP houses the strip foundation is included in the price, screw piles add €3,000 to the turnkey version and a poured slab €5,000. How to pick the right type and why the geotechnical survey comes before the budget.
Published: September 12, 20266 min read
On the designs in our catalogue the strip foundation is already included in the price. If the plot calls for something else, screw piles add €2,500 to the insulated kit and €3,000 to the turnkey house, while a poured slab adds €4,000 and €5,000 respectively. Those are the only figures anyone can give you before seeing the land — the rest falls into place after the geotechnical survey.
You will find foundation prices per square metre online, quoted for "an ordinary house". We do not publish figures like that, because the foundation is the one line in a quote that does not follow the design: the same house on three different plots can call for three different foundations and three different budgets. That is why on our price page the foundation appears as a separate line instead of being folded into the total.
Why the foundation follows the plot, not the house
Four things decide the type of foundation and none of them is visible in the floor plan: how much load the soil carries, how steep the slope is, how high the water table sits and how deep the ground freezes in your area. The fifth is access: if heavy machinery cannot reach the plot, some solutions are out from the start.
A SIP house does start with a real advantage: it is far lighter than a brick or aerated-concrete one, so it loads the ground less and accepts a slimmer foundation than the same house built in masonry. The advantage shows up in the cost, but it does not overrule the soil. The full comparison of the two technologies is in SIP versus brick.
The three types and what each adds to the price
| Foundation type | Right when | Insulated kit | Turnkey |
|---|---|---|---|
| Strip (continuous) | Level plot, load-bearing soil, low water table | included | included |
| Screw piles | Slope, soft or wooded ground, minimal disturbance | +€2,500 | +€3,000 |
| Poured slab | Level plot, larger house, underfloor heating | +€4,000 | +€5,000 |
We build three solutions: continuous strips, screw piles and a poured slab. The sums below are exactly what is added to the price of the design you choose from the catalogue — not a market estimate, but the options in every house configurator.
The difference is the same for every design in the catalogue, from the 39.6 m² cabin to the 151.4 m² family house. It is an indicative sum, confirmed in the offer once we know what the geotechnical survey says; the remaining chapters of a full budget are taken apart in the 100 m² cost breakdown.
Strip foundation: the one included in the price
Continuous strips are the classic foundation: trenches are dug along the load-bearing walls, reinforced concrete is poured below the frost line and the house rests on that belt. It works on a relatively level plot with load-bearing soil and no water near the surface, which describes most house plots in Romania.
Precisely because it is the most common case, we include it in the price of every design. If your plot falls into this category, the catalogue price is also the price of your foundation, and what remains to budget is transport from Baia Mare, the utility connections and the permit fees.
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Screw piles: slopes, soft ground, wooded plots
Screw piles are steel tubes with a helix, screwed into the ground down to the load-bearing layer, carrying the beams the house sits on. They usually go in within a day or two, with no concrete and no curing time, and the plot stays almost untouched: no large excavation, no access road for heavy machinery, no trees taken out.
That makes them the standard answer for holiday cabins, for sloping mountain plots and for glamping investments, where minimal disturbance of the land is the selling point itself — the numbers behind that business model are in our article on glamping. The second case is soft ground, made ground or land with water near the surface, where a classic foundation would mean deep digging and a lot of concrete: the piles pass through the weak layer and rest on the good one, and the price stays predictable.
Poured slab: a larger house and underfloor heating
The slab is a reinforced concrete raft poured over the whole footprint of the house. It spreads the weight evenly, which helps on soil that carries unevenly, and it is the ideal base for underfloor heating — the reason it is mostly asked for by people building a family house rather than a holiday cabin.
In exchange it needs a level or levelled plot, more concrete and curing time before the structure goes up. If you want a warm floor throughout the house anyway, part of the difference comes back: you no longer pay for the screed and the sub-layer you would have built over another type of foundation.
The geotechnical survey is what actually decides
The type of foundation is not picked from a catalogue but from a geotechnical survey: a specialist drills on the plot, establishes the soil layers, the bearing capacity and the water table, then writes the founding recommendation. The survey is paid separately, to a local geotechnical engineer, and it is not a formality invented by builders; it is part of the permit documentation.
The right order is simple: first the urbanism certificate and the geotechnical survey, then the choice of design and foundation, then the fixed offer. The other way round, you risk budgeting for strips and finding out at the first dig that you need piles. The permit steps, with their documents and timelines, are in our building permit guide.
What stays outside the foundation price
The price of the foundation covers the foundation, not the plot. Outside it stay major levelling, retaining walls on steep slopes, drainage where water runs down from above, the access road for machinery and the connections to water, electricity and sewage. Those last ones are the most unpredictable chapter of the whole budget, because they depend on the distance to the network rather than on your house.
The good news is that none of these sums arrives as a surprise: they are all put on the table during the consultation about your plot, before the contract, and the price fixed afterwards is not recalculated.
Three mistakes that cost money
The first: choosing the foundation by price instead of by soil. A few thousand euros saved come back later as cracks, settlement and repairs no warranty covers, because the house was never the problem.
The second: pouring the foundation before the final design. The foundation has to match the footprint and the bearing points of the kit exactly; a slab poured "roughly right" is either broken up or extended, and both cost more than waiting. Producing the kit takes 2–4 weeks from order confirmation anyway — the full stage-by-stage calendar is in how long a SIP house takes to build.
The third: ordering the foundation from a crew that never speaks to the house manufacturer. When the foundation and the house come from separate contracts, at the first problem each side points at the other. With the turnkey version you have one party answerable for the whole chain; what exactly each formula includes is in what the insulated kit contains.
The next step, if you already have land: send us the locality and, if you have it, the urbanism certificate. We pick the design together, settle the foundation type after the geotechnical survey and you get a fixed price for the whole job.
How much does the foundation of a SIP house cost?
On the designs in our catalogue the strip foundation is included in the price. Screw piles add €2,500 to the insulated kit and €3,000 to the turnkey house, a poured slab €4,000 and €5,000 respectively. The right type is settled after a geotechnical survey of your plot.
Which foundation suits a sloping plot?
Usually screw piles: they are screwed into the ground down to the load-bearing layer and absorb the change in level without major levelling, retaining walls or an access road for heavy machinery. They go in within a day or two, with no concrete, and add €3,000 to a turnkey house.
Is the foundation included in the catalogue price?
Yes, in the strip version, both for the insulated kit and for the turnkey house. The other two types appear as a separate option in every design configurator, so you see at once how the total changes. Transport, utility connections and permit fees stay outside the price.
Can my own crew pour the foundation before I order the house?
You can, but only once the design is confirmed: the foundation has to follow the exact footprint and bearing points of the kit. A foundation poured "roughly right" has to be corrected or broken up. The kit is produced in 2–4 weeks, so waiting for the final design does not delay the site.
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