Topographical surveys are often called `topo’ surveys, detail surveys, terrain surveys, or contour surveys; they all refer to laser-measured land surveys which gather data about natural and man-made features on your site to create a map.
A topographical survey will also locate exactly all relevant features such as existing buildings and structure, physical boundary details, walkways, service cover positions, trees and tree positions, underground services, slopes, and site and spot levels.
Using highly specialised survey equipment, land surveyors normally present this geo-referenced data digitally, in CAD format, to create accurate topographical drawings of the land with all site features outlined as well as additional details about features adjacent to the site. This information allows you to then adjust your plan if necessary, according to the constraints and opportunities of your site.
Why might I need a topographic survey?
The main reasons are:
- To help a planning application to progress.
- To avoid the risk of costly mistakes: a topographic survey can protect you from unforeseen issues with a site, for example, it may reveal that the proposed development may be too close to the boundary line for comfort, leading to a planning application rejection. It may reveal that the area of land is unsuitable, for example by identifying certain clay soils that expand and contract with rainfall and temperature changes, leading to unstable ground, possible subsidence and heave. Having a survey at an early stage could alter your drainage schemes and it could also highlight the need for a tree survey, which could save considerable time later. In certain cases, a topographic survey can avoid plan changes and costly errors further down the line.
- Accuracy: any surveys undertaken following the topographic survey will be based on that survey, giving them the benefit of working from accurate land measurements.
- To enable you to make the most of every development opportunity from your site. Every scheme has different elements, the larger or more complex the project, the greater the likely need for a topographical survey. Ultimately, it comes down to a question of risk – a land survey can tell you everything you need to know about your site’s specific needs, giving you an accurate picture to help base decisions on from an early stage.
How will a topographic survey benefit my plan?
A topographical survey provides a sound foundation for your design, and information can be collated into maps, models, CAD drawings and charts to help:
- Choose the right location for any new buildings.
- Identify opportunities to enhance the value of your scheme.
- Take into account off-site or near-site risks that could pose engineering challenges.
- Avoid encroaching on or building over boundary services.
- Mitigate risk from natural and manmade features.
- Uncover unseen hazards like buried foundations.
- Identify manmade and natural topographic features that could indicate a need for further surveys before a scheme can obtain planning consent.
- Having a topographic survey could help you to avoid going through rejections and committees with your scheme.
- It’s an advantage to be able to give building contractors detailed information early so that they have a clear indication of the project.
- Having accurate land measurements, and information on existing site boundaries and ground heights can save considerable time and reduce cost in the long run.
- A topographic survey will give you peace of mind that you have all the accurate data you will need to progress with your development site.
Potential problems that can be highlighted by topographical surveys:
- Issues with site boundaries or drainage ditches.
- Construction projects planned too close to a retaining wall that could cause a structural collapse.
- Not maximising your development site fully: a topo survey may enable you to explore development options previously dismissed as unworkable.
Topographical survey stages:
- Firstly, an initial discussion is held with a topographical surveyor about the site to decide on the level of detail required.
- Experienced surveyors visit the site, and set up equipment which might include cameras, accurate GPS equipment, laser scanning spot and site levels, and handheld devices. This kit can capture accurate measurements and other detailed information that the land surveyors need to create accurate drawings of the survey area.
- In the case of difficult sites to cover, for instance involving steep inclines, busy roads or collapsed structures, surveyors can undertake drone surveys that can provide photos or laser scans. Topographical surveyors can also gather data from external sources such as Ordnance Survey or the local authority where necessary.
- With this level of spatial information, land survey teams can create CAD drawings according to your requirements. The design team can include 2D drawings resembling conventional maps or models in three dimensions.
Ready to get started with your topographical survey?
Experienced topographical survey firm Arbtech Consulting Ltd, carries out surveys priced from £399+VAT, depending on the scheme’s scale and complexity. The majority of their work relates to residential, commercial and industrial development, mainly on urban, green and brownfield sites. To find out more contact Arbtech.
