Our survey skills can be applied at every stage of a demolition project, from initial planning through to the site being cleared. Individual sector types are detailed on other pages of our website, such as highways and railways, so here we want to emphasise our involvement across the full lifecycle of a demolition.
For a demolition, the surrounding site needs to be understood first but, in addition, we provide laser scan data of the structure’s surroundings to enable visualisation for the planners and public. The site and surrounding structures can be modelled and placed within a 3D model for viewing from all angles. The proposed works can even be seen using virtual reality (VR). If the surroundings are captured (by ground based laser scanning, aerial lidar or photogrammetric methods) then additional analyses can be undertaken such as right to light, noise studies, the effects of wind tunnelling and monitoring of movements during the demolition.
On larger projects the survey can be split into an early feasibility stage before the full go-ahead, keeping costs down until the demolition is confirmed. More often nowadays, using modern laser scanning or lidar, we can capture data suitable for both the feasibility assessment and the detailed demolition planning in a single visit, with minimal cost difference.
The survey data can be captured in a single commission, though if time has passed since the feasibility stage an update may be needed to confirm nothing on site or in the surroundings has changed. It is important to establish permanent survey control on site for the demolition contractors to work from, and Merrett Survey Limited are experts in installing and surveying high precision survey control networks.
Throughout the demolition, the site can be monitored against the original survey to confirm the works are progressing safely and as planned. Progress measurement can be undertaken by updating the BIM model from ground based scanning, or overall site monitoring using UAV or drone imagery. Rapid 360° imagery can also be provided on a regular basis to enable ‘immersive’ views of the progress of the demolition.
Before work begins, an as-existing survey records the building exactly as it stands, including the utility services running through it: the Heating, Ventilation and Air Conditioning (HVAC) ducts and cables, drainage, plus MEP (Mechanical, Electrical and Plumbing) services. Knowing precisely where these run is essential for isolating and stripping them out safely before the structure comes down.
Where only part of a structure is being removed, accurate survey data of the retained building makes the remaining works safer and easier to plan, and doing this via the BIM model is increasingly the chosen method.
Before a building comes down, surveyors can be called in to make rapid BIM models of large buildings so that the demolition can be planned safely and economically. What are the floor thicknesses? Can they bear the weight of demolition machinery/plant ? What are the overall quantities or volumes of concrete, number of steel columns and beams?
If you would like to discuss our demolition survey services in detail and to determine how we can benefit your project, please contact our team of surveyors.
