Construction project complexity
Improving Infrastructure Delivery: Project Initiation Routemap, Handbook, Version 2 June 2016, published by the Infrastructure and Projects Authority, states: ‘Project complexity is a measure of the inherent difficulty of delivering a project based on factors such as stakeholder alignment; interconnectedness of projects; systems & organisations and the level of innovation required etc. The Routemap uses the Delivery Environment Complexity Assessment (DECA) published by the NAO for complexity assessment.’
Project Routemap, Setting up projects for success, Organisational Design & Development, UK Module, published by the Infrastructure and Projects Authority in 2021, states: ‘In the context of Routemap, project complexity is a measure of the inherent difficulty of delivering a project. This is assessed on factors such as the stability of the wider delivery environment, the level of innovation required, and the number of stakeholders involved.’
ICMS: Global Consistency in Presenting Construction Life Cycle Costs and Carbon Emissions, 3rd edition, November 2021, published by the ICMS (International Cost Management Standard) Coalition, defines Project Complexity as: ‘The relative intricacy of a Project or Sub-Project by reference to its form, design, site constraints, method or timing of construction, renewal, operation, maintenance or end of life activities.’
Cost prediction, Professional Statement, 1st edition, published in November 2020 by the Royal Institution of Chartered Surveyors (RICS), defines complexity as: ‘The number of elements, their interactions and the strength of impacts on a defined system with regard to decision making, project control and predictable asset delivery.’
See also: Complexity theory and Complex project.
[edit] Related articles on Designing Buildings
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Guide to ISO 19650 for Architecture Firms (2026)
A user gives their low down.
A UK training and membership provider for mould remediation professionals.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
Independent NSI and BAFE study exploring how organisations are changing the way they buy fire safety services.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.
Comments
[edit] To make a comment about this article, or to suggest changes, click 'Add a comment' above. Separate your comments from any existing comments by inserting a horizontal line.