Survey Set-Outs and How These Help In the Construction Process of Residential Buildings in Australia

Surveying is rather a refined practice which has its own expertise. Before the construction, of anything, it is necessary to a have a site survey plan done to set out boundaries, levels and recognise/identify factors that may affect the build.

In Australia, strict legislative laws govern surveyors defining their qualification, their type of work and other such things.

A registered land surveyor clearly marks and defines the boundary of the land on which the construction is to take place. This also helps identify any encroachments on the land or any improvements that can be made.

Now that we have established the basics, we need to find out how a routine survey takes place. Before any construction happens, surveyors, clearly mark the boundaries and all key points on the land. This helps in determining the legality and planning of the project. Set-out surveys are extremely important in constructing high rise buildings, bridges and others of the sort, but they should not be ignored even for minor projects such as the construction of a small retaining wall or a boundary fence.

The basic theme of a site survey is also to investigate levels of the lot which involves the use of instruments such as automatic levels, levelling staffs, optical plummets, theodolite, laser scanners, ranging rods, prismatic compass, Electronic Distance Measuring Equipment (EDM), etc. Without going into much detail, all these modern scientific and engineering wonders help the surveyors accomplish the jobs they are assigned to.

A key component of the surveying process is the set out grid and from this the contours and levels are determined.

Let us first discuss the grids.

Surveys are accomplished by comparing readings from one area with another, so patterns can be recognised. The best way to do this is to take readings at regular intervals, using a set out grid. This then determines levels and subsequent land contours.

Next up is the land contours.

Contour plans are a graphical representation of the terrain of the land. They show the degree of slope on a site. They typically relate back to a site datum referred to as a temporary benchmark (TBM) and/or may also relate to the Australian Height Datum (AHD). A datum is any level surface, line, or point used as a reference in measuring elevations. In short, contouring represents the vertical dimension of terrain on a two-dimensional map.

Contour plans can be used (for example) to determine the extent of cut and fill needed, the height of retaining walls, and/or the overall finished height of buildings – referenced back to the natural ground level.

All of the aforementioned surveying process helps in the determination of levelling needed. Where required, excavation or fill will be done on site to achieve the required levels for the build.

An important topic worth mentioning here is the grading of the soils. The topography of the area plays a huge role in laying out the grading plan for the building and construction process. Grading is an important step carried out prior to construction that helps prevent water from flowing towards the foundations of the building site. If this is not performed correctly, stormwater may damage the foundations of the building overtime, which can cause catastrophic results.

To find out more about survey set-outs and how we can help you get these for your next project, get in contact with us.

Disclaimer: this guide should not be used as sole guideline for any application, construction or intent to build any development.