Construction budget: a guide to drawing up a cost estimate 2026

A turnkey detached house in Finland typically costs €2,700–3,000/m² in 2026, meaning a 120 m² house usually comes to €250,000–350,000 in total. At their widest, turnkey prices range from €2,000 to €4,000 per square metre, and a small detached house can be completed for around €150,000–350,000 all in; log houses run at €2,500–3,500/m². A budget that holds is built from three parts: a realistic cost estimate, the right cost breakdown and a contingency reserve of 10–15 per cent. The bank requires a cost estimate before granting a construction loan, so you will be drawing one up before starting in any case.

What makes up the cost of a detached house?

• House package including erection: 55–70%
• Groundworks and foundations: 10–15% (€25,000–50,000)
• Building services (HVAC and electrical): 8–12% (€20,000–35,000)
• Interior finishes and fittings: 8–10%
• Utility connections, permits and supervision: 3–5% (€7,000–15,000)
• Landscaping: 3–5%

In traditional stick-building from loose timber, labour accounts for 30–40 per cent of the total budget and building services for 15–25 per cent. The biggest single uncertainty, however, lies in the groundworks: plot-to-plot variation is €20,000–60,000, and the soil decides the difference. That is why a ground investigation should be commissioned before locking the budget – preferably before the plot purchase. The percentage breakdown is also a quick sanity check: if a quote deviates from it sharply, find out why before signing.

Are construction costs still rising?

Moderately. After the 2022 cost spike the level stabilised: in 2024 costs stayed essentially flat, in 2025 the rise was 0.9%, and in 2026 the pace has been 1.5–1.9% a year. The rise is unevenly spread: in 2025, labour inputs rose 1.9% and materials 0.8%, while services fell 2.7% – and timber structures rose the most, 7.6%. In spring 2026, timber prices were climbing at over seven per cent a year. The cost pressure now comes from labour and timber, no longer from general materials inflation. A budget can be built on a fairly stable footing, but in a long project allow for index-linked increases. In practice, a quote requested a year ago is no longer comparable without an update.

What do interest rates mean for the budget?

The 12-month Euribor stood at around 2.9% in July 2026. Rates are well below the 2023–24 peaks, when Euribor topped four per cent, but they have risen by about 0.7 percentage points over the past year. Do not build your budget on the assumption of cheaper money. Access to finance is a bottleneck for many projects: house factories report that financing delays or even halts planned builds. That makes a careful cost estimate the single most important tool in financing negotiations too. An underdimensioned estimate does not speed up the loan decision – it comes back from the bank for completion.

Who draws up the cost estimate, and how?

The cost estimate is typically drawn up by the principal designer, the responsible site manager or the house supplier at the design stage, before construction begins. A sensible order of work: first a rough target price at square-metre level, then the ground investigation and groundwork prices, then comparable quotes from house suppliers, and finally a line-item breakdown against which actual spend is tracked. The cost estimate is not a one-off document but a living tool, and every invoice is checked against it.

Your own labour typically saves around €400–500/m², but only if the amount and schedule of that labour have been assessed honestly. Note too that Finland's household expenses tax credit does not apply to new construction – it cannot be counted into the budget.

Example budget: 118 m² turnkey

A real-life example of a turnkey modular house with ground-source heating: total price around €283,000 excluding the plot. The sum broke down as follows: house package €225,200, groundworks €40,000, permits and utility connections €12,500, and supervision and design €5,000. The example shows the proportions well – on top of the package come some €55,000–70,000 of other costs, which many people underestimate in their first budget.

How to make the budget hold

• Commission a ground investigation before locking the budget.
• Split the budget into packages – groundworks, frame, services, interiors, landscaping – and track actuals package by package.
• Set aside a 10–15% contingency; nearly every project needs it.
• Update the cost estimate every time the plan changes.
• Include utility connections, permits and landscaping: together 6–10% of the budget.
• Tender the biggest packages competitively – the house package, groundworks and building services make up the lion's share of costs.

• A turnkey detached house typically costs €2,700–3,000/m² in 2026; a 120 m² house €250,000–350,000.
• The house package takes 55–70% of the budget, groundworks and foundations 10–15%, or €25,000–50,000.
• Groundworks vary €20,000–60,000 from plot to plot – commission a ground investigation before locking the budget.
• Construction costs are now rising moderately, about 1.5–1.9% a year; the rise comes from labour and timber.
• The 12-month Euribor was around 2.9% in July 2026 – well below the 2023–24 peaks.
• Always set aside a 10–15% contingency; the bank requires a cost estimate for the loan decision.