1. What the index measures
The Statistics Estonia definition is precise and worth reading literally: the index expresses the change in the cost of construction activity at the level of direct costs on site. The definition also marks out its field of use.
| Element | Content |
|---|---|
| The three main groups of direct costs | labour, construction machinery, materials |
| The four building groups included | houses, apartment buildings, industrial buildings, office buildings |
| The repair and reconstruction price index | the buildings under observation are office buildings |
The last row is a methodological limitation that is rarely noticed, covered in the article on the four building groups: the repair index is built on office buildings, not dwellings. It concerns the composition of the sample.
2. What it does not measure
This is where the commonest misunderstanding arises. The index does not measure what a client pays.
| What is excluded | Why |
|---|---|
| The contractor's overheads and profit | the direct cost level does not contain them, although they are part of every quotation |
| Plot, design, permits, connections | these do not occur on site |
The index is therefore not an indicator of price level but an indicator of change, and only for one layer of cost. Its whole logic of use follows from that.
The practical consequence: if the index rises 3 %, that does not mean quotations rise by exactly 3 %. Overheads and profit may move in a different direction, and the off-site portion does not move with the index at all.
3. What recent quarters show
Two consecutive quarters in 2026 illustrate the logic well. They show two different sources of price pressure.
| Quarter | Year on year | Against previous quarter | Main driver |
|---|---|---|---|
| 2026 Q1 | + 2 % | + 0.5 % | wage growth |
| 2026 Q2 | + 3.1 % | + 1.9 % | rising material prices |
Two consecutive quarters, two different drivers. That is the index's most useful property: it shows not only how much, but why.
The difference is practical. Growth driven by wages affects labour intensive buildings more strongly; growth driven by materials affects material intensive ones. The same index movement therefore affects two projects differently, depending on which component drove it.
4. When to use it and when not
| Use it | Do not use it |
|---|---|
| To update an older estimate where a fresh calculation is not possible | To justify one specific quotation |
| As the basis of a contractual price adjustment, where agreed | To transfer between building types |
| To follow market direction, without a specific project |
The second prohibition is the most important and the most often broken: applying the house index to an office building, or the reverse, transfers a cost structure that is not the same. The sub-indices move differently.
The index is published quarterly, and in a contractual context the indicator used must be named precisely, because without that an indexation clause is not unambiguous. The quarter agreed must be named in the contract.
In summary, and four practical rules
The construction price index is the only official figure in this field, but it measures direct costs on site, split between labour, construction machinery and materials, and excludes overheads, profit and the entire off-site portion. In the first quarter of 2026 it rose 2 % year on year on wage growth, in the second 3.1 % on material prices.
Four rules: read the index as an indicator of change, not of price level. Look at which component drove the movement, because that changes its effect on your project. Do not transfer the index between building types. Name the indicator used precisely in a contract.
This article serves professional orientation at the date of checking. It is not a quotation.