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How much a house foundation costs in 2026, and how to choose: strips, slab or concrete piers
The foundation is the one part of the house that depends on your plot rather than on the design. On our SIP houses it is part of the shell on a foundation (from €400/m², against €300/m² without one) and, through it, of the turnkey price. How strips, slab and concrete piers are chosen, why screw piles come out dearer, and why the geotechnical study comes before the budget.
Published: September 12, 2026Updated: October 14, 20267 min read
On the designs in our catalogue the foundation is part of the price of the shell on a foundation, from €400/m², and, through it, of the turnkey price, from €900/m². If you already have a builder for the foundation, the same shell without foundation starts from €300/m². The gap between the two is the only figure anyone can give you before seeing the land, from €10,000 for a 100 m² house; the rest falls into place after the geotechnical study.
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 We do not publish figures like that, because the foundation is the one line in a quote that does not follow the design: the same house on three different plots can call for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 shell comes in two versions, with and without foundation, and we set the foundation type by the plot, not from a table of surcharges.
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, and the one with aerated-concrete masonry in SIP or aerated concrete.
The three types and when each one is used
| Foundation type | Right when | Worth knowing |
|---|---|---|
| Strip with a concrete slab | Level plot, load-bearing soil, low water table | The classic solution: reinforced concrete below the frost line, with curing time |
| Concrete piers | A light house, where the geotechnical study allows point supports | Less concrete than strips; still poured concrete, so still curing time |
| Monolithic slab (raft) | Level plot, larger house, underfloor heating | A good base for a warm floor; needs a level plot and curing time |
We build three solutions: continuous strips with a concrete slab, a monolithic slab (raft) without strips, and a foundation on concrete piers. The type does not change the catalogue option: any of them goes into the shell on a foundation, and the exact sum is fixed after the consultation, once we know what the plot needs. We do not publish per-type surcharges, because that would be a market estimate, not the price of your foundation.
The gap between the shell on a foundation and without one follows the house area, the difference between €400/m² and €300/m²: from €4,000 for the 39.6 m² cabin to €15,500 for the 151.4 m² family house. It is a "from" price, not the price of a particular foundation type: the exact sum is confirmed in the offer once we know what the geotechnical study says; the remaining chapters of a full budget are taken apart in the 100 m² cost breakdown.
Strip foundation: the most common case
Continuous strips are the classic foundation: trenches are dug along the load-bearing walls, reinforced concrete is poured below the frost line, and a concrete slab poured inside that outline carries the house. It works on a relatively level plot with load-bearing soil and no water near the surface, which describes most house plots in Romania.
It is the most common case, but with us it has no separate price: like any foundation type, it goes into the shell on a foundation. If your plot falls into this category, what remains to budget on top of the house price is the utility connections and the permit fees; we agree delivery from Baia Mare together with the design, and then it is part of the final price in the offer.
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Concrete piers: point supports for a light house
With a pier foundation, instead of a continuous belt, reinforced concrete piers are poured at the bearing points of the house, below the frost line. A SIP house is light, so where the geotechnical study allows point supports, piers are enough for it and take less concrete than strips.
It is still a poured foundation, so it needs curing time before the structure goes up. It is part of the shell on a foundation like the other two types, and where screw piles come up, which we cover below, concrete piers are the option we recommend.
Monolithic 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, the slab saves a step: you skip the screed and the sub-layer you would have built over another type of foundation.
Screw piles: possible, but dearer than a slab
Screw piles are steel tubes with a helix, screwed into the ground down to the load-bearing layer. They go in quickly and with no concrete, which is why they are often recommended for cabins and sloping plots. We can build them, but with a condition that changes the sums: for a screw-pile foundation to be approved, the piles have to be screwed in to a set torque, and that torque is measured by a machine with an on-board computer.
Measuring the torque and issuing the documents that confirm it is done by a specialist service, paid for separately. With it, a screw-pile foundation comes out dearer than a slab. That is why we recommend concrete piers instead; the final type is still decided by the geotechnical study.
The geotechnical study is what actually decides
The type of foundation is not picked from a catalogue but from a geotechnical study: a specialist drills on the plot, establishes the soil layers, the bearing capacity and the water table, then writes the founding recommendation. The study is paid separately, to a local geotechnical engineer, and it is not a formality invented by builders; it is part of the permit documentation. In a seismic zone its report also feeds the structural calculation, not only the choice of foundation, set out here.
The right order is simple: first the urban planning certificate and the geotechnical study, 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 the plot needs something else. 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 house exactly; a slab poured "roughly right" is either broken up or extended, and both cost more than waiting. The panels are ready about 6 weeks from the deposit anyway (up to 8 if the design is adapted), since orders are produced in the order they come in — 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 shell on a foundation and with turnkey you have one party answerable for the whole chain, from foundation to roof; with the kit for self-assembly the foundation stays with you. What exactly each option includes is in our guide to the kit and the shell.
The next step, if you already have land: send us the locality and, if you have it, the urban planning certificate. We pick the design together, settle the foundation type after the geotechnical study 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 foundation is part of the shell on a foundation (from €400/m²) and of the turnkey house (from €900/m²). Without foundation, the shell starts from €300/m², so the gap starts from €10,000 for a 100 m² house. The right type and the exact sum are settled after a geotechnical study of your plot.
Which foundation suits a sloping plot?
It depends on the soil and on how steep the slope is: the geotechnical study decides the type, not the gradient on its own. Strips with a slab, a monolithic slab and concrete piers are all part of the price of the shell on a foundation, and the exact sum is fixed after the consultation. Screw piles, often recommended for slopes, come out dearer than a slab with us: getting them approved needs a separate, paid measurement of the screw-in torque.
Is the foundation included in the catalogue price?
Yes, in the shell on a foundation and in the turnkey house, whether it is strips with a slab, a monolithic slab or concrete piers. Every design page also shows the shell without foundation, if you want your own builder to lay it, and the kit for self-assembly, where the foundation also stays with you. Utility connections and permit fees stay outside the price, while delivery, agreed together with the design, is part of the final price in the offer.
Can my own crew pour the foundation before I order the house?
Yes, that is what the shell without foundation is for, from €300/m². The foundation is laid to our drawings and only once the design is confirmed: it has to follow the exact footprint and bearing points of the house. A foundation poured "roughly right" has to be corrected or broken up. The panels are ready about 6 weeks from the deposit, so waiting for the final design does not delay the site.
Prices are indicative and shown for general information only: they are “from” figures for the standard design under typical conditions. For your plot, design and specification the final sum may differ; we fix the exact price in the offer after a consultation.
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