The demolition industry has a certain character for being a tough environment in which brute force takes precedence over calculated thought; however this image is far from appropriate. There is a substantial amount of work that happens behind the scenes of the demolition and construction sector which is firmly rooted in the academic world. Furthermore, this unseen work is essential to the success of the more visible operations.

One part of this unnoticed work is site surveying, or more precisely pre-demolition and post-demolition topographical surveying. This sort of work demands a good balance of specific technical knowledge as well as experience of the industry and a natural intuition for the intricacies of the job.

Topographical Surveys

A topographical survey is a study of the actual features of a given piece of land. The aim of a topographical survey is to chart the naturally occurring and man-made traits of a particular landscape to a high degree of accuracy. Whilst topography itself may refer to the surface of any object, it is more commonly associated with the surface of the Earth.

Topographical surveys can be carried out on a very wide range of landscapes, from open countryside to urban areas and across a variety of elevations and land surfaces. Surveys can be developed to take into account a great number of factors, such as ground conditions or vegetation, and as such can be used for a number of tasks.

Common Applications for Topographical Surveys

Perhaps the most extensively used, and most generally recognised application for topographical surveys is cartography, or map making. Modern day maps include a great amount of information about the terrain they relate to, including waterways, elevations and ground surface, all of which will have been collected via a topographical survey. This information is also being made available online.

Topographical surveys also have a major role to play in the construction industry. When individuals or organisations are looking to build any kind of structure they will need to carry out extensive surveys as part of the design stage of the project.

Surveys definitely play a key safety part in primary industries such as mining, or in other industrial sectors that interact with the terrain, such as demolition and infrastructure. Companies in these industries will use surveys to prepare their projects, but also to make sure that they can guarantee the safety of their workforce on site. As a result, topographical surveys are often a legal requirement for these types of projects.

The newly understood medical risks of asbestos make asbestos demolition surveys crucial in jobs where older structures are being demolished.

Types of Survey

The world of topography covers a large number of physical features so it is important to determine what type of topographical survey is suitable for a particular scenario.

“Lie of the land” Surveys

These types of topographical surveys are fashioned to create an overview of the physical characteristics of any given plot of land. Although the information gathered by the survey will be extremely accurate, and can be very extensive, the purpose of these surveys is to give a site summary.

These surveys will usually include a boundary survey that sets out to determine the extent of the site and highlight any specific restraints that are determined by the geography of the site. They can also include a level survey that will plot the elevation of the terrain and the various gradients that exist.

Building Surveys

Building surveys are more generally concerned with man-made constructions on a site, including the surveying of special machines and even infrastructure features. This type of study is more commonly associated with the demolition sector because it can give a detailed plan of the building to be demolished.

A building survey will probably include a measured survey, which entails creating a precise plan of the external and internal dimensions of a structure. Depending on the requirements of the project, a measured survey might provide basic building “footprint” measurements, or might produce a very detailed plan of the structure. This information can be used to generate internal floor plans and even roof plans.

Content of a Topographical Site Survey

A survey of a demolition site will almost definitely include the information gathered by the types of boundary and building surveys described above. This information will be needed so that the demolition firm can plan a demolition that is both adequate and secure.

Surveys will often include information about the utility services that are present on a site before any demolition or construction work happens. This is an essential safety factor since any unmonitored damage to pipes and cables carrying water, gas and electricity might be very dangerous.

Another aspect of the site survey will often be an inventory of resources on the site. This type of study will be a quantity survey of the various types of materials that can be located on site, for example, tiles and masonry, concrete that can be used as hardcore or even timber. By getting an accurate audit of site materials the construction company can more precisely gauge the need to import building resources, or they can re-use the materials on a different job.

Modern construction and demolition companies provide details within their own company website so customers can view case studies or references regarding past projects.

Importance of Site Surveys

Maybe the most important reason to undertake a topographical site survey is to ensure the safety of the individuals who will be working on the site. The industries that most commonly call for site surveys are risky enough as it is without having to worry about the integrity of the ground on which they are working.

Another important reason to get a proper survey done is to identify any potential problems that may arise because of the physical properties of the region. Certain things will not be evident on the surface of the site and will only be uncovered once digging or demolition has begun.

The inventory of site materials, as previously stated, can be of great value to a demolition or construction company working on a project. Not only are building materials themselves expensive, but importing them to the site could be a very expensive task in itself. Any time that material can be recycled on site offers an opportunity to save development time and money.

Topographical surveys can also highlight other areas that will be of use to the project planners. For example, if the gradients on a site would be prohibitive to particular vehicles or equipment then a new access route or alternative equipment will have to be found.

Positioning of Survey Control

During the surveying and construction phases of a building project, the equipment required for the physical surveying of the site and control of the survey data will often be stored on-site. This is obviously a problem when it comes to the demolition period of a project since the equipment is both costly and sensitive.

Once the demolition has occurred and the site has been deemed safe for staff to return to it, the surveying equipment can be restored to its initial position on site. This will allow for efficient data collecting to take place for a post-demolition survey, and retains a single point of contact for anybody who needs the topographical survey information.

It is essential to perform surveys before and also following the demolition of buildings because disruption of energy services must be supervised closely.

Who can Perform Site Surveys?

Since topographical site surveys can play such a crucial role in the success or failure of a building or demolition venture it is vital that they are undertaken thoroughly by the right people. There are different branches of site surveying and each one will have unique certificates associated with it.

When selecting a company to undertake the surveying work required for your project it will be sensible to choose a company with a good reputation and a proven track record. Ask to see reviews of their previous work and try to obtain feedback about their overall performance on past projects.

Who will use the Survey Information?

Once an adequate level of details has been gathered by a site survey it must be handed out to the appropriate people on-site. Who gets which pieces of information will largely depend on the job roles being performed, but can also rely on the stage that a project is at.

Project Planners

Project planners will generally require access to all of the information gathered by a topographical survey, although they will particularly need to use information concerning the physical relief of a site before the design phase, and a site materials inventory before they can plan the construction phase. The more data that can be made available to project planners will help the smooth running of the venture.

Demolition Experts

Demolition companies will want to know about the interior and external properties of any building or structures that they are arranged to take down. Whilst every job will have different requirements, demolition experts will typically need to know about the fundamental framework of a building and the materials it is made out of.

Site Engineers

Construction engineers on-site will be particularly interested in the survey data about the relief and topography of the site. It is usually the case that they will want to assemble on a flat surface, so they will use information about the natural lay of the land to determine what work will be required to create a stable footing for any structure.