Civil Engineering Reference
In-Depth Information
8.9 Site layout planning
General considerations
Every project has its own site layout problem, either too little space or too much
(as in the case of this hotel and office project). Space available for site layout plan-
ning must be considered as a “flexible space”. As a project progresses from the
foundation stage to completion there is a change in the materials being stored
and handled. The key to good site layout planning is therefore flexibility and think-
ing ahead.
Foundations and in-situ concrete frame construction create a need for space for
fabricating reinforcement and formwork. Areas are also required for cleaning of the
formwork and recovering usable materials. Access is required for ready-mixed con-
crete deliveries.
Steel-framed construction again requires extensive space for the storage of steel-
work on the ground prior to lifting into position. Extensive space is also required for
movement of plant and mobile lift platforms around the building.
When cladding operations commence, again space is required for glass storage
frames and trestles. A clear space around the building is required for the movement
of scissor lifts, hydraulic platforms and so on.
It is essential that consideration is made to placing materials on the floor space
created within the building. This applies to items such as insulation materials,
dry lining and plasterboard products, which need protection from the weather.
Items such as bathroom pods may be positioned in each room during
construction.
A forecast will be required of the number of office staff and operatives to be on site
at peak times. This will influence the number of office units required and the canteen
and drying rooms and toilet space to be provided for operatives and staff.
Site preliminaries encompass all areas of providing site facilities. This includes the
provision of site accommodation, site services to maintain cabins, including electric-
ity, erection and dismantling costs.
The estimator has to make a judgement at tender stage of the monies to be
included in the estimate for such items. Average preliminaries allowances often
equate to 6 - 12% of the contract sum.
It is necessary to keep a check during construction of the actual expenditure
incurred in providing these services. Part of the monthly cost/value reconciliation
process involves comparing the estimated allowances with the actual costs incurred.
Many contractors overspend on contract preliminaries, especially when contract
delays occur.
