Building Services Tender Price Index (BSTPI) is a quarterly index compiled by the Architectural Services Department as an aid to adjust building services installation cost data for estimating purposes. It also provides an indication of the level of tender prices of building services installation for new building works under Capital Works Programme. The BSTPI is computed in a similar way to the Building Works Tender Price Index (BWTPI) managed by the Architectural Services Department. The value in the 4th quarter of 1989 is taken to be the base index value of 100, and subsequent values are expressed in index form based on the 4th quarter of 1989 value.

# "Three-Quarter Moving Average” showing the trend of the BSTPI is calculated as follows: