In brief

• The costs of electricity increased by 16.9 percent in January 2026 compared to December 2025 and were 11.0 percent higher compared to January 2025.
• The cost of diesel oil decreased by 2.2 percent in January 2026 compared to December 2025 and were 11.2 percent lower compared to January 2025.
• Interest costs increased by 0.7 percent in January 2026 compared to December 2025 but were 5.6 percent lower compared to January 2025.

Changes in the last month

The Construction Cost Index for multi-dwelling buildings increased by 0.3 percent between December 2025 and January 2026. This increase was due to the fact that both the contractors’ costs rose by 0.3 percent and the construction clients’ costs rose by 0.4 percent. 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 2.9 percent. Within that group, the cost of electricity rose by 16.9 percent while the costs of diesel oil and transport fell by 2.2 percent and 0.3 percent, respectively. Contractors’ overhead costs increased by 0.4 percent while the costs of machinery and wages and salaries were unchanged.

Contractors’ costs for building materials increased by 0.2 percent in January 2026. Among the building material groups, the costs of plumbing products and white goods rose the most by 0.9 percent and 0.5 percent, respectively. The costs of floor material, woodwork and other building materials fell by between 0.1 and 0.5 percent. The remaining material costs were unchanged or rose slightly between December 2025 and January 2026.

Construction clients’ costs increased by 0.4 percent in January 2026. Construction clients’ costs consist of interest and credit costs, costs for plans, and central administration. The increase in construction clients’ costs was due to both higher interest costs and the cost of official employee wages which both rose by 0.7 percent.

Changes in the last year

The Construction Cost Index for multi-dwelling buildings increased by 1.2 percent between January 2025 and January 2026. Contractors’ costs rose by 1.8 percent, which led to an upward contribution to the Construction Cost Index of 1.4 percentage points. Construction clients’ costs decreased by 1.1 percent, which led to a downward contribution to the Construction Cost Index of 0.2 percentage points. The decreased construction clients’ costs was due to lower interest costs, which decreased by 5.6 percent while the cost of official employee wages increased by 3.6 percent. The remaining construction clients’ costs increased by between 0.5 percent and 2.9 percent.

Contractors’ costs of ‘wages and salaries’ and overhead costs increased by 3.3 percent and 2.5 percent respectively, while costs for machinery decreased by 0.1 percent between January 2025 and January 2026, The costs for ‘transport, fuel and electricity’ increased by 0.9 percent compared to January 2025. Within this group the cost for electricity increased by 11.0 percent while the costs of diesel oil and transport decreased by 11.2 and 0.4 percent respectively.

Contractors’ costs of building materials increased by 1.2 percent between January 2025 and January 2026. All costs in the building material groups rose except the cost of electric materials and other building materials, which both decreased with 1.1 and 1.7 percent respectively. The costs of wood products and woodworks increased the most, by 5.7 percent and 3.6 percent respectively.