- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 14 Dec 2016
The term 'base year' refers to the year that is the starting point for a series of years in an economic or financial index. It can be used for comparing business activities, economic growth, measuring inflation and so on across a number of years.
It is usual for the base year to be set to an arbitrary level of 100. For example, if the base year is set as 2014:
- 2014: 100
- 2015: 102.5
- 2016: 107
This simple index series shows a growth rate in the first year of 2.5%, and of 7% between the first year and the third year.
(Current year - Base year) / Base year
Using the figures above:
(107 - 100) / 100 = 7%
For a more precise index, a 'base month' can be set instead.
Within construction contracts, the 'base date' is a reference date from which changes in conditions can be assessed. It sets the reference date from which the conditions under which the tender was prepared are considered to have been known by the contractor and so are properly reflected in their price. If specified conditions change before the contract is implemented, then the contract may be adjusted to reflect this.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
A guide to daylight design for commercial buildings.
Two opposite approaches to cost estimating that can work together.
BSRIA reports on propsects for the US construction industry.
ECA research shows lack of preparation amongst survey respondents.
Smart mapping approaches for building better infrastructure.
The importance of emergency planning.
Eight forms of resource optimisation.
CIOB responds to Chancellor Sunak's announcement on jobs and the economy.
Revised guide to competition rules available.
Brick slip soffit systems and intricate brick features.
An innovative engineering approach could have had tragic consequence for NYC.
Some secrets behind how canals work.