- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 01 Dec 2020
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
The principles and art of the possible. Book review.
From horse and cart to hypermarket.
How elements and processes work together in a systems approach.
CIOB offers digital guide to proactive methods of working.
Tech will drive professional development in fields tied to infrastructure.
The idea for the structure emerged from the architect's dream.
Changing air tightness requirements prompt testing and revisions.
Government takes steps to revise building safety legislation.
Product can be 'grown' into bricks or used as a self-healing building material.
Anticipating COVID-19's continuing construction disruptions.
Availability payment arrangements involve project performance.
EU responds to COVID-19 with NextGenerationEU plan.