Preliminaries in construction
Contents |
[edit] What are preliminaries?
Preliminaries (or 'prelims') may form part of tender documents used to obtain bids for construction works or for the supply of goods or materials. Preliminaries provide a description of a project that allows the supplier (often a contractor or subcontrator) to assess costs which, whilst they do not form a part of any of the packages of works required by the contract, are required by the method and circumstances of the works. NBS suggest that 'the purpose of preliminaries is to describe the works as a whole, and to specify general conditions and requirements for their execution, including such things as subcontracting, approvals, testing and completion.' Preliminaries and work sections together describe what is required to complete the works required by the contract.
The costs attached to preliminaries may also be referred to as 'preliminaries' or 'prelims', or as 'site overheads', or general cost items or expenses. The Code of Estimating Practice published by the Chartered Institute of Building (CIOB) describes preliminaries as: '...the cost of administering a project and providing general plant, site staff, facilities, and site based services and other items not included in the rates.'
[edit] What might preliminaries include?
Preliminaries in tender documents might include:
- A general summary.
- Method statements.
- Pre-construction information.
- A description of any planning conditions or other conditions that may affect the works.
- A description of any outstanding statutory approvals that may fall to the supplier to satisfy.
- Party wall requirements or other agreements with, or rights of, neighbours (such as rights to light).
- Any emergency services obligations.
- A description of the reporting information that the supplier will be required to submit (often on a monthly basis) describing construction progress (including a detailed critical path programme, key performance indicators and earned value analysis). See Construction progress reports for more information.
- A description of the commissioning strategy, separating setting to work and balancing tasks from independent verification by the consultant team.
- Relevant reports (such as soil reports).
- An information release schedule.
- Quality management procedures.
- Labour relations.
- Schedules of mock-ups, testing and samples required from the supplier.
- The method of sub-contracting.
- Requirements for insurance, performance bonds, warranties and product guarantees.
- Requirements for the operating and maintenance manual.
- Requirement for progress photos to be taken on site during construction and off-site during fabrication.
- Dates for partial possession.
- Collaborative practices.
- Building information modelling (BIM) requirement and protocols (including requirement for BIM in sub-contracts).
- Site waste management plan.
- Contractor's site preliminaries, such as; staff, welfare provisions, site offices, plant, site waste clearance, water, electricity, furniture, ICT and consumables, rates, protection of work, protective clothing, site transport, setting out, building control fees, and so on.
NB: Preliminaries should not be confused with 'preambles' which set out things such as tendering procedures, that will not affect the contractor's price. For more information, see Difference between preliminaries and preambles.
[edit] Other definitions of preliminaries
According to NRM1: Order of cost estimating and cost planning for capital building work, main contractor’s preliminaries are; '...items which cannot be allocated to a specific element, sub-element or component. Main contractor’s preliminaries include the main contractor’s costs associated with management and staff, site establishment, temporary services, security, safety and environmental protection, control and protection, common user mechanical plant, common user temporary works, the maintenance of site records, completion and post-completion requirements, cleaning, fees and charges, sites services and insurances, bonds, guarantees and warranties. Main contractor’s preliminaries exclude costs associated with subcontractor’s preliminaries, which are to be included in the unit rates applied to building works.'
NRM1 defines ‘subcontractor’s preliminaries’ as; ‘…preliminaries that relate specifically to building work which is to be carried out by a subcontractor. Costs associated with subcontractor’s preliminaries are to be included in the unit rates applied to sub-elements and individual components.’
According to ‘Elemental Standard Form of Cost Analysis, Principles, Instructions, Elements and Definitions, 4th (NRM) Edition’ written by RICS in 2012 and published by BCIS, ‘the cost of preliminaries for the building being analysed should be stated and expressed as a percentage of the contract sum excluding preliminaries, contingencies and, where appropriate, contractor’s design fees.’
[edit] Related articles on Designing Buildings
- Bill of quantities BOQ
- Code of estimating practice
- Contingencies in construction
- Difference between preliminaries and preambles
- Form of tender
- Method statement for construction
- New code of estimating practice
- Overheads
- Preamble in construction contracts
- Pre-construction information
- Prime cost sum
- Profit and overheads on construction projects
- Provisional sum
- Subcontractor’s preliminaries
- Tender documentation for construction projects
- The difference between a prime cost sum and a provisional sum
Featured articles and news
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help the homebuilding sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.
Delayed, derailed and devalued
How the UK’s planning crisis is undermining British manufacturing.
How much does it cost to build a house?
A brief run down of key considerations from a London based practice.
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.
Demonstrating that apprenticeships work for business, people and Scotland’s economy.
Scottish parents prioritise construction and apprenticeships
CIOB data released for Scottish Apprenticeship Week shows construction as top potential career path.
From a Green to a White Paper and the proposal of a General Safety Requirement for construction products.
Creativity, conservation and craft at Barley Studio. Book review.
The challenge as PFI agreements come to an end
How construction deals with inherited assets built under long-term contracts.
Skills plan for engineering and building services
Comprehensive industry report highlights persistent skills challenges across the sector.
Choosing the right design team for a D&B Contract
An architect explains the nature and needs of working within this common procurement route.
Statement from the Interim Chief Construction Advisor
Thouria Istephan; Architect and inquiry panel member outlines ongoing work, priorities and next steps.



























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.
All of these “preliminaries” are quantifiable, so why should they be expressed as a percentage of the overall costs? This seems a lazy and sloppy way to calculate them, and not particularly accurate, and a licence to print money for the contractor.
In response to comment above: It's true that prelims are quantifiable after the event (eg. at final account) but the best a Contractor can do when tendering on a fixed price basis is make an appropriate allowance to cover the prelim costs it expects to incur. In doing so, it is left with the risk should it incur greater prelim expense during the execution of the works (save for instances like variations, where those costs arose due to factors outside of the Contractor's control). The approach proposed by the OP above would leave all the risk with the Employer and a Contractor could easily substantiate additional prelim costs if it were so inclined.