Risk allowance
The New Rules of Measurement (NRM) are published by the Royal Institute of Chartered Surveyors (RICS). They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects.
According to NRM1: Order of cost estimating and cost planning for capital building work, the term 'risk allowance' refers to:
'...the amount added to the base cost estimate for items that cannot be precisely predicted to arrive at the cost limit.'
Where the 'base cost estimate’ means:
‘…an evolving estimate of known factors without any allowances for risk and uncertainty, or element of inflation. The base cost estimate is the sum of the works cost estimate, the project/design team fees estimate and the other development/project costs estimate.’
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 risk allowance as: ‘A quantitative allowance set aside as a precaution against risks and future needs to allow for the uncertainty of outcome. This may include an allowance for optimism bias and a contingency sum.’
[edit] Related articles on Designing Buildings
Featured articles and news
A case study and a warning to would-be developers
Creating four dwellings for people to come home to... after half a century of doing this job, why, oh why, is it so difficult?
Reform of the fire engineering profession
Fire Engineers Advisory Panel: Authoritative Statement, reactions and next steps.
Restoration and renewal of the Palace of Westminster
A complex project of cultural significance from full decant to EMI, opportunities and a potential a way forward.
Apprenticeships and the responsibility we share
Perspectives from the CIOB President as National Apprentice Week comes to a close.
The first line of defence against rain, wind and snow.
Building Safety recap January, 2026
What we missed at the end of last year, and at the start of this...
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses, their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description from the experts at Cornish Lime.
IHBC planning for growth with corporate plan development
Grow with the Institute by volunteering and CP25 consultation.
Connecting ambition and action for designers and specifiers.
Electrical skills gap deepens as apprenticeship starts fall despite surging demand says ECA.
Built environment bodies deepen joint action on EDI
B.E.Inclusive initiative agree next phase of joint equity, diversity and inclusion (EDI) action plan.
Recognising culture as key to sustainable economic growth
Creative UK Provocation paper: Culture as Growth Infrastructure.
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
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.