# What is the BDB index?
**The BDB index is a price index number that measures the development of construction costs in the Netherlands.** BDB stands for ‘Bureau Documentatie Bouwwezen’ (Bureau for Construction Documentation). The index is used to adjust building costs, contract sums, and maintenance budgets to current price levels.
## How it works
The index is periodically calculated based on:
– **Labour costs** — development of collective agreement wages in construction
– **Material costs** — price trends for building materials
– **General costs** — overheads, transport, and energy
By multiplying a construction sum by the ratio of the current index to the historic index, the sum is corrected for inflation.
## Application
– **Long-term maintenance budgets** — realistic estimation of future costs
– **Construction contracts** — in contracts with a price escalation clause
– **Cost comparisons** — making construction costs from different years comparable
– **Reserve funds** — keeping owners’ association maintenance funds up to date
## Related terms
– Construction costs
– Specification
– Contractor
– Building price
– Variation (additional work)
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