In brief

• The costs of transport decreased by 1.1 percent in May compared with April 2026 but were 8.0 percent higher than May 2025.
• The cost of diesel oil decreased by 6.4 percent in May compared with April 2026 but was 39.2 percent higher than May 2025.
• The cost of electricity increased by 9.7 percent in May compared with April 2026 and was 7.4 percent higher than May 2025.
• Interest costs increased by 1.5 percent in May compared with April 2026 but were 4.5 percent lower than May 2025.

Changes in the last month

The Construction Cost Index for multi-dwelling buildings increased by 1.2 percent between April and May 2026. This was due to the fact that both the contractors’ costs and the construction clients’ cost rose by 1.2 percent each. These two groups account for 82 percent and 18 percent, respectively, of the Construction Cost Index.

Costs in the group ‘transport, fuel and electricity’ increased by 0.1 percent. Within that group, the cost of diesel oil and transport fell by 6.4 and 1.1 percent respectively, while the cost of electricity rose by 9.7 percent. Contractors’ overhead costs increased by 0.1 percent, while the costs of machinery and ‘wages and salaries’ increased by 0.2 percent and 2.8 percent respectively.

Contractors’ costs for building materials increased by 0.9 percent in May 2026. Among the building material groups, the costs of other building materials rose the most by 4.0 percent. The costs of reinforcement steel and materials for painting rose by 3.9 and 2.4 percent respectively. The costs of woodwork and plumbing material both fell, by 0.1 and 0.2 percent respectively. The remaining material costs increased by up to 2.2 percent between April and May 2026.

Construction clients’ costs increased by 1.2 percent in May 2026. Construction clients’ costs consist of interest and credit costs, costs for plans, and central administration. The increase in construction clients’ costs was mainly due to higher costs of interests and higher costs for plans. 

Changes in the last year

The Construction Cost Index for multi-dwelling buildings increased by 2.3 percent between May 2025 and May 2026. Contractors’ costs rose by 3.0 percent, which led to an upward contribution to the Construction Cost Index of 2.4 percentage points. Construction clients’ costs decreased by 0.5 percent, which led to a downward contribution to the Construction Cost Index of 0.1 percentage points.

Contractors’ costs for ‘wages and salaries’ and overhead costs both increased by 2.7 percent respectively. Costs for machinery was unchanged between May 2025 and May 2026. The costs for ‘transport, fuel and electricity’ increased by 10.5 percent compared to May 2025. Within this group the costs of diesel oil and transport increased by 39.2 and 8.0 percent, respectively. Cost of electricity increased by 7.4 percent.

Contractors’ costs for building materials increased by 2.8 percent between May 2025 and May 2026. Among the building material groups, the costs of other building materials rose the most by 6.5 percent. Subsequently, materials for painting and reinforcement steel increased by 5.7 and 5.1 percent respectively. All other material groups increased by up to 3.5 percent, except for wood products which fell by 2.4 percent.

Construction clients’ costs decreased by 0.5 percent. Among the construction clients’ costs, the interest costs decreased by 4.5 percent, while the costs for official employee wages, according to collective agreements, increased by 3.7 percent. The remaining costs rose by between 1.0 and 2.6 percent. 

Changes for users retrieving data via the API

In the autumn of 2025, PxWebApi v1 was replaced by the new PxWebApi v2. PxWebApi v1 will remain operational until the turn of the year 2026/2027, after which it will no longer be available. For further information and guidance on the transition, see:

PXWebAPI v2