Building an Extension – Professionals You Need In 10 Easy Steps: Schedule of works or Bill of quantities

Schedule of works

Step 5 Schedule of works or bill of quantities

After completing the Design Update We are now ready to start building the tender pack that will go out to the list of contractors, more about the contractors and how to select them in the next stage contractor selection

Schedule of works also abbreviated to SoW

The schedule of works is basically what it says on the tin, an orderly list of the works that will be required to carry out your project.

This is put together in the same logical order that the project will be built, broadly this will be under the following headings

  • Site preparation
  • Groundworks & drainage
  • Floor slab or block and beam
  • Brickwork
  • Roof structure
  • Roof coverings
  • Windows
  • Plumbing
  • Electrical
  • Heating
  • Carpentry
  • Fixtures and fittings (Kitchen for instance)
  • Decorations
  • Furnishings
  • Final clean

The schedule of works does not need to have any meaningful measurements of the works to be priced by the contractor but must either have a supporting specification or the specific requirements included within the items listed above, alternatively it can be quantified as well

Each heading can then be detailed further to allow the contractor to fully understand the work required

Bill of Quantities which is abbreviated to BoQ

The Bill of Quantities is of a similar format and structure as the Schedule of Works although produced in NRM format which is the RICS standard for New Rules of Measurement, simply NRM2 is a set of measurement rules   

Defined by Royal Institute of Charted Surveyors  The primary purposes of a bill of quantities (BoQ), which becomes a contract document, are: to provide a co-ordinated list of items, together with their identifying descriptions and quantities, that comprise the works to enable contractors to prepare tenders efficiently and accurately

The time taken to prepare a BoQ is greater than the Schedule of Works route as all items require measurement or quantification and an extended index of information and documents, in real world scenarios the Bill of Quantities is normally suited to larger projects where the level of detail is in relation to the type and complexity of works.

A Bill of Quantities can provide more certainty to the returned tenders at that time although as the reliance will be on the actual measured works this cost can increase and consequentially will make the reduction of any works easier to manage and agree upon

Next let’s look at step 6 Contractor selection