Introduction to off-site construction and construction sequence

Introduction to off-site construction and construction sequence

Date Published

15 August 2022

Document Type



Offsite construction is based primarily on two key principles: efficiency and quality. It is defined as the manufacture and pre-assembly of components, elements or modules before installation into their final location on site. The concept of offsite construction is to allow manufacture of parts of the building in an environment best suited for effective production, where advanced equipment can be used to increase productivity.

Furthermore, offsite construction improves working conditions by taking construction processes to a clean controlled environment unaffected by climatic conditions, as well as helping to reduce waste. The more parts of buildings are completed offsite, the less needs to be done onsite.

Key Information

Offsite construction is based primarily on two key principles of efficiency and quality.

Offsite manufacture may not guarantee greater durability, but factory production should reduce the risk of non-conformities, related premature failures and consequent repairs associated with onsite assembly.

The main risks with offsite construction are: late design changes, loss of factory production slot, failure to meet building tolerance and accuracy requirements and supply failure.

Case studies

In the summer of 2015 the idyllic shoreline of Lymington-Keyhaven Nature Reserve was home to a pair of lightweight timber cabins, known collectively as The Observatory.

The new Performing Arts Centre for Sevenoaks School sits on a beautiful sloping site overlooking Knole Park. It contains a concert hall large enough for a symphony orchestra, choir and an audience of 450, a recital room for 100, and a music school with 23 teaching spaces of various sizes, plus a new drama studio, with drama teaching and technical spaces.