Outturn cost
The term ‘outturn’ or ‘out-turn’ refers to an amount achieved in a certain time, for example, an actual amount produced, or actual sales made. This is in contrast with the amount that might have been predicted or estimated. It is thought to be derived from, or related to, the term ‘turn out’.
The ‘outturn cost’ or ‘out-turn cost’ of a project is its actual construction cost. Generally this refers to the actual, total construction cost calculated at the end of the project, but it may also refer to the cost of a specific contract, or to costs incurred over a defined period. This contrasts with cost estimates, or target costs, which are calculations of the cost that is expected, or the cost that should be achieved.
This meaning of outturn cost is slightly confused by the use of terms such as ‘forecast outturn cost’, ‘estimated outturn cost’ or ‘target outturn cost’ which refer to the cost that is anticipated or should be achieved at the end of the project.
According to the Royal Institution of Chartered Surveyors (RICS), these outturn cost comprises: fixed costs, variable costs, variations, fluctuations and risk allowances.
- Fixed costs are costs that have been pre-calculated and agreed to be paid.
- Variable costs include; provisional sums, provisional quantities, prime cost sums and daywork allowances.
- Variations are alterations in the form of additions, substitutions or omissions from the original scope of works.
- Fluctuations are a way of dealing with inflation on large projects that may last for several years. The contractor is asked to tender based on current prices (prices at an agreed base date) and they are then reimbursed for price changes to specified items over the duration of the project (a fluctuating price).
- Risk allowances are financial allowances for works or services that are unknown in terms of quantity and specification, and are the client’s risk.
Cost prediction, Professional Statement, 1st edition, published in November 2020 by the Royal Institution of Chartered Surveyors (RICS), defines out-turn cost (‘final account’, ‘actual cost’ or ‘cost outcome’) as: ‘The known cost at the end of a project. Generally, it refers to the actual, total construction cost calculated at the end of the project, which includes the effects of any changes made to the design and the impact of any disruption. It may also refer to the costs incurred over a defined period, such as in life cycle cost.’
See also: Final account.
[edit] Related articles on Designing Buildings
- Balance sheet.
- Bill of quantities BOQ.
- Budget.
- Capital costs for construction projects.
- Construction costs.
- Contract conditions.
- Contract sum.
- Cost plans for construction projects.
- Cost reporting.
- Cost Value Reconciliations (CVR).
- Disallowed cost.
- Discounted cash flow.
- Elemental cost plan for design and construction.
- Final account.
- Prime cost sum.
- Quantity surveyor.
- Sunk cost.
- Types of cost.
[edit] External references
Featured articles and news
What they are, how they work and why they are popular in many countries.
Plastic, recycling and its symbol
Student competition winning, M.C.Esher inspired Möbius strip design symbolising continuity within a finite entity.
Do you take the lead in a circular construction economy?
Help us develop and expand this wiki as a resource for academia and industry alike.
Warm Homes Plan Workforce Taskforce
Risks of undermining UK’s energy transition due to lack of electrotechnical industry representation, says ECA.
Cost Optimal Domestic Electrification CODE
Modelling retrofits only on costs that directly impact the consumer: upfront cost of equipment, energy costs and maintenance costs.
The Warm Homes Plan details released
What's new and what is not, with industry reactions.
Could AI and VR cause an increase the value of heritage?
The Orange book: 2026 Amendment 4 to BS 7671:2018
ECA welcomes IET and BSI content sign off.
How neural technologies could transform the design future
Enhancing legacy parametric engines, offering novel ways to explore solutions and generate geometry.
Key AI related terms to be aware of
With explanations from the UK government and other bodies.
From QS to further education teacher
Applying real world skills with the next generation.
A guide on how children can use LEGO to mirror real engineering processes.
Data infrastructure for next-generation materials science
Research Data Express to automate data processing and create AI-ready datasets for materials research.
Wired for the Future with ECA; powering skills and progress
ECA South Wales Business Day 2025, a day to remember.
AI for the conservation professional
A level of sophistication previously reserved for science fiction.
Biomass harvested in cycles of less than ten years.
An interview with the new CIAT President
Usman Yaqub BSc (Hons) PCIAT MFPWS.
Cost benefit model report of building safety regime in Wales
Proposed policy option costs for design and construction stage of the new building safety regime in Wales.
Do you receive our free biweekly newsletter?
If not you can sign up to receive it in your mailbox here.


























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.