The demolition industry has a certain character for being a harsh atmosphere in which brute force takes precedence over calculated thought; however this image is far from appropriate. There is a huge amount of work that goes on behind the scenes of the demolition and construction industry that is firmly grounded in the academic world.

One branch of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This sort of work demands a good balance of specific technical know-how as well as experience of the industry and a genuine intuition for the intricacies of the job.

Topographical Surveys

A topographical survey is a report of the actual features of a particular piece of land. The aim of a topographical survey is to map the naturally occurring and man-made traits of a particular landscape to a high degree of precision. 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 broad range of landscapes, from open countryside to urban developments 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 variables 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 commonly recognised application for topographical surveys is cartography, or map making. Modern maps include a great deal of information about the landscape they relate to, including waterways, reliefs and ground surface, all of which will have been collected via a topographical survey. This information is also being offered online.

Topographical surveys also have a key role to play in the construction business. 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 phase of the project. These surveys are often an essential part of any application for planning permission as well.

Surveys also play a key safety role in primary industries like mining, or in other industrial sectors that interact with the terrain, such as demolition and infrastructure. Companies in these industries will use surveys to plan their projects, but also to be sure that they can ensure the safety of their staff on site.

Though it is not always the perfect option, a demolition survey may always be carried out while preparation work is occurring on-site.

Types of Survey

The arena of topography covers a large number of physical characteristics so it is important to determine what type of topographical survey is appropriate for a particular situation. A few of the more common types of survey necessary for construction sites are discussed below.

“Lie of the land” Surveys

These types of topographical surveys are fashioned to create a summary of the physical characteristics of any given plot of land. Although the information collected by the survey will be extremely accurate, and might be very extensive, the purpose of these surveys is to give a site summary. They will often be the first type of topographical survey that is carried out on a project.

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

Building Surveys

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

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

Content of a Topographical Site Survey

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

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

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

Topographical surveys and resource quantity reviews make up one branch of demolition services made available by contemporary companies that comply with business best practices.

Importance of Site Surveys

Perhaps the most important reason to perform a topographical site survey is to ensure the safety of the people who will be working on the site. The industrial sectors that most frequently call for site surveys are risky enough as it is without having to be concerned about the condition of the ground on which they are working.

Another important reason to get a suitable survey done is to highlight 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 supplies, as previously mentioned, can be of great benefit to a demolition or construction company working on a project. Not only are construction materials themselves costly, but importing them to the site may be a very expensive task in itself. Any time that material can be recycled on site provides an opportunity to save development time and funds. Only by taking an exact audit of these materials can a company properly plan its imported material needs.

Topographical surveys can also highlight other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to specific vehicles or equipment then a new entry route or alternative machinery will need to be found. Equally, an appropriate site will need to be found for the base of management operations for the project. Good site surveying can help out in these less tangible ways.

Positioning of Survey Control

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

Once the demolition has taken place and the site has been deemed safe for personnel 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 anyone who requires the topographical survey information. Most surveying firms will oversee this redeployment.

Las Vegas is the backdrop for a good deal of commercial demolition because old hotels require flattening so that newer ones can be built in their place.

Who can Perform Site Surveys?

Since topographical site surveys can play such a critical role in the success or failure of a construction or demolition venture it is vital that they are undertaken carefully by the correct people. There are different divisions of site surveying and each one will have specific qualifications associated with it. Finding surveyors with these specific skills will certainly be advantageous.

When choosing a company to undertake the surveying work required for your project it will be wise to choose a company with a good reputation and a proven track record. Ask to see reviews of their previous work and try to get feedback about their overall performance on past projects. It may also be worth thinking about how a company can deliver their survey information, i.e. in 3-D models or CAD ready formats, for ease of integration with other members of the project staff.

Who will use the Survey Information?

Once an adequate level of information has been gathered by a site survey it needs to be passed out to the appropriate personnel 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. There will be less need for materials information midway through construction for example.

Project Planners

Project planners will generally need access to all of the information collected by a topographical survey, though they will particularly need to use information about the physical relief of a site before the design phase, and a site materials record before they can prepare the construction phase.

Demolition Experts

Demolition companies will want to know about the internal and exterior characteristics of any building or structures that they are arranged to take down. Whilst every project will have individual requirements, demolition workers will generally 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 mainly interested in the survey information 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 details about the natural lay of the land to determine what work will be required to create a steady foundation for any building. They will want this information before and in the course of the construction stage of a project.