Cost plans or BOQs, particularly those used at early design stages will often include average prices calculated on a per m2 basis for various construction elements. Whilst useful when the dimensions and thickness are common (such as brick wall or windows) it is not so straightforward when we see “x m2 of structural steel” or “x m2 of foundation concrete”. There are a few options that can be followed depending on what stage the design is at and what sort of information is available.
- Go back to design team/QS/ or the drawings/documentation and find more accurate material quantities in m3/kg. Typically these may not be available until later stages of the design so option 2 or 3 will need to be followed until more accurate quantities can be updated at later stages.
- Utilise our “m2” templates which average quantities on a per m2 basis. These can be quite high-level estimations as quantities vary significantly depending on the size/span/density of the project but good for early-stage (2) analysis. For example “Foundation system strip foundations 300mm (m2)” template averages strip foundations on a per m2 of ground floor area. We also have larger whole building templates (search “(TS)” in the library for even earlier stage analysis when all that is known is a gross floor area and use.
- Utilise our “£/$” templates which average material quantities based on expenditure such as “Foundation reinforced concrete 40Mpa 1.5% reo (£)” Or for steel framing, we have this one “Framing structural steel (universal beam column etc) £”
We encourage users to also create their own “m2” or “£/$” templates as applicable to their circumstances. By using project data from projects at more advanced stages quantities may be averaged on m2 or £/$ basis for use on other similar projects. Please get in touch if you would like further assistance with this.
The important thing is not to wait until the design has developed to the stage where detailed quantities are available as you may miss out on the opportunity to present the alternatives. Make an assumption and get the discussions flowing as quickly as possible.
Better to be vaguely right than be precisely wrong!