Contractor's proposals for building design and construction

Revision as of 15:06, 12 September 2014

Contractor's proposals are prepared by tenderers for design and build projects (or on a traditional contract where the contractor is to design discrete parts of the works) as a response to employer's requirements. The employer's requirements provide a description of the client's requirements, including the specification for the building, the scope of services required from the contractor and an allocation of risk for unknown items. The contractor's proposals set out their proposals for designing and constructing the building, along with their price.

The level of detail in the employer's requirements and the extent of design required from the contractor is very variable. Employers requirements can range from a very simple specification to a fully developed performance specification and concept design.

Design and build projects can follow either a single-stage or two-stage tender processes. A single-stage tender process is suitable where the information presented in the employer's requirements is sufficiently well developed for the contractor to be able to calculate a realistic price. This can be the case either if a concept design has already been prepared by consultants working for the client, or if the building is very straight-forward, in which case much of the design work might be carried out by the contractor during the tender process. A two-stage tender process is suitable where the employer's requirements are not sufficiently well developed for the contractor to be able to calculate a realistic price. In this case, the contractor will tender a fee for designing the building along with a schedule of rates that can be used to establish the construction price for the second-stage tender.

The format and content of contractor's proposals should be as described in the employer's requirement's, but they might include:

• Design drawings.
• Specifications.
• Schedules.
• Method statements.
• A programme.
• The tender price and contract sum analysis.
• Details of inconsistencies between the contractor's proposals and the employer's requirements.
• Any proposed provisional sums.
• Proposed sub-contractors (the contractor may only sub-contract parts of the works with the consent of the client, although this consent cannot be unreasonably withheld).
• Details of insurances.
• Curriculum vitae of staff along with a summary of their relevant experience on similar projects.
• An initial construction phase plan.

Once the client has received the contractor's proposals, there is likely to be period of negotiation during which any inconsistencies between the contractor's proposals and the employer's requirements are discussed and either the contractor's proposals or the employer's requirements are amended to ensure agreement between them. This is a very important part of the tender process as it is not always entirely clear which document prevails after the contract has been entered into.

Find out more

Related articles on Designing Buildings Wiki

• BIM execution plan.
• Construction phase plan.
• Contract sum analysis.
• Contractor.
• Design and build.
• Employer's agent.
• Employer's information requirements (BIM).
• Employer's requirements.
• Method statement.
• Novation.
• Procurement route.
• Programme.
• Provisional sum.
• Specification.
• Supply chain capability summary (BIM).
• Tender.
• Two stage tender.

External references

• Building article: Procurement: Employer’s agents
• Workplace Concepts: Developing your Employer's Requirements before appointing a contractor.