As-built surveys are a crucial final step in a construction project. They provide accurate and detailed records of the completed building work, demonstrating compliance with building regulations, deviations from original specification, and asset details important for property managers, future maintenance, and developments.
What are as-built surveys?
An as-built survey is conducted once a construction project is complete, to compare the original design plans to the final build. They’re also conducted at several stages throughout a project to monitor progress and find any departure from the original plan.
They capture every element of the construction, including dimensions, measurements, and materials. Finer details on building feature configurations are also collected, including:
- Earthwork formations
- Steel frames
- Drainage systems
- Concrete slabs
- Holding down bolts
The survey data is used to create 2D plans, 3D models, annotated CAD drawings, and comprehensive documentation of the construction project. SEP Engineers supply data in industry-standard formats, including PDF, DWG, and DXF, for seamless integration with BIM platforms and project management systems.
When is an as-built survey required?
There are a range of construction scenarios where an as-built survey is essential, including:
- Foundation surveys: One of the most common types of as-built surveys is foundation surveys, completed after foundations are laid and before building work commences, to ensure the project is following strict building codes and is to specification.
- Stormwater surveys: Building developments must determine the area of impervious surfaces, including pavements, building roofs, and roads, which prevent water drainage and increase flood risks.
- Water systems: An as-built survey details the exact locations of all the components of a drainage and sewage system, including pipes, manholes, and valves. This information is invaluable should any issues arise in the future, as remediations could be deployed rapidly.
Construction sites as built surveys
As-built surveys are crucial throughout a construction project, ensuring that at all stages of construction, the original design plans are adhered to, and all building regulations are followed. Regular progress monitoring can prevent costly errors and time-consuming remedial work.
When construction work is finished, an as-built survey captures the buildings’ locations, dimensions, utilities, and site features. This is invaluable for property owners to confirm compliance, plan renovations, and for future building sales.
As-built surveys for transport networks
It’s critical that transport networks, such as railways and highways, are constructed in line with design specifications to ensure compliance and public safety. An as-built survey can identify potential hazards that need addressing, preventing issues from arising.
As-built surveys for rail
Railway as-built surveys capture all project details, including tracks, signalling systems, and tunnels. Ensuring adherence to original plans can prevent costly mistakes, schedule delays, and improve operational efficiency.
Highway as-built surveys
Highway as-built surveys, also known as roadworks quality assurance surveys, capture information on road positioning, utilities, manholes, kerb lines, and links to existing roads. An as-built survey is essential for project sign-off – without one, the road cannot be used by the public.
SEP Engineers’ as-built survey process
1. Consultation and project review
Our engineers begin the as-built survey process by assessing the project’s original planning documents, so we can later compare reality to the expectations. We also collect information on the planning permissions and building regulations related to the project.
2. On-site data collection
We gather data on-site with 3D laser scanners. They rapidly emit millions of laser pulses, which bounce back from objects and return to the scanner. The time taken to return is used to calculate the distance and create a highly detailed 3D point cloud, which architects and project managers can use to virtually walk through a building.
Alongside scanners, we also use GNSS receivers and total stations to accurately determine locations and measurements of buildings, utilities, elevations, and boundaries.
We work with the latest cutting-edge technology from brands including Trimble, Leica, and CHCNAV.
3. Data processing and analysis
We convert field data into visualisations of the construction, typically as 3D models, 2D maps, and drawings, using specialised software. We prepare digital copies in a format that suits the project manager.
4. Project manager handover and review
We present our findings to the project manager, who can then find any deviations from the original project goals and plans. The as-built survey can also be used by architects to plan future development projects and renovations.
Get an as-built survey you can trust from SEP Engineers
Whether you’re working on a transport project, a construction site, or a drainage system, SEP Engineers has the experience and expertise to conduct an as-built survey you can trust. Get in touch with one of our engineers via the contact form below, and we’ll be in touch to discuss your project’s needs.
Submit your enquiry below – we aim to respond within 1 hour (during business hours Monday to Friday)
Frequently Asked Questions
1) How much does an as-built survey cost?
No two construction projects are the same, and our prices are bespoke to each project, dependent on their complexity and scale. Once we have gathered all the relevant details from you, including size, location, and level of detail required, we will provide you with a quote.
2) How long does it take to conduct an as-built survey?
The time an as-built survey takes depends on the size of your site, ease of access, and the number of surveys you require. Get in touch to discuss your project and we can provide you with a quote.
3) What format do you supply the final as-built survey in?
We supply as-built surveys in a format to suit your project’s needs, including 2D CAD drawings, 3D models, and point clouds. Traditional 2D drawings of detailed floor plans, elevations, and site layouts are usually provided in PDF or DWG files. Our 3D models and point clouds provide a greater level of detail, capturing every site feature.
