Top Down construction

Airey Taylor Consulting has developed the conventional use of the Top Down construction technique for general use in the building industry in Western Australia.

Top Down construction has vastly improved the speed of project delivery and offers dramatic capital cost improvement whilst providing excellence of finish to any build, enhancing and reducing resource usage, improving cost and reducing pollution.

The principle of Top Down construction is to install the vertical load-bearing elements and the retaining system using piles and retaining walls constructed from the natural ground level prior to excavating. A cast insitu lid (the future suspended ground floor) is then constructed covering the area to be excavated. This is followed by excavating under the lid to the required depth, while simultaneously construction of the superstructure proceeds, hence the name.

Top down construction for buildings permits the construction of upper floor levels simultaneously with excavating under the ground-floor slab and casting the basement floors below. Essentially, Top down construction dispenses with the requirement to excavate a below-ground pit prior to construction commencement, enabling use of the site from day 1 for deliveries. It greatly reduces the damage to adjoining buildings that is associated with soil movement and eliminates the need for sheet piling.