Understanding what is included in a topographic survey

1. Scale and grid

To maintain accuracy, all elements in a topographic survey are drawn to scale. The survey will include site levels on a maximum 5m/10m grid and soil mounds, with additional measurements taken at any significant changes in height. Understanding the site’s topography, helps identify areas requiring earthworks, drainage considerations, or foundation design adjustments. This also allows architects to visualise the contours of the land and construction professionals to understand the relationships various physical features informing planning and construction design.

2. Highway levels

For sites adjacent to highways, a topographic survey includes levels at specific intervals such as the back of footpaths, top and bottom of kerbs, and the crown of the road. This information helps to understand the connection between the site and the adjacent infrastructure, facilitating road design, access planning, and drainage assessments.

3. Plans of buildings and structures

Plans of Buildings and Structures: Existing structures within the site boundary are shown on the plans including relevant details such as name, number, and description. Roof overhangs will be depicted using a broken line and, door positions with opening directions will be indicated. This creates awareness of spatial constraints and integration of the existing structures into the construction plans

4. Internal levels of buildings

Your topographic survey will also include internal levels. This is crucial data for architects, engineers, and construction teams when designing and coordinating construction activities within existing structures.

5. Eaves and ridge heights

Understanding the heights of adjacent properties is vital to assess the impact of the new construction on the surrounding environment. This knowledge informs design coordination, compliance with local regulations and ensures the new design sits harmoniously withing the surrounding structures.

6. Utility structure

The topographic survey also identifies inspection covers, manholes, drains, gullies, earth rods, and stopcocks. Including these elements helps architects plan around existing infrastructure, enabling them to coordinate the development of designs with utility providers and avoid conflicts during construction.

7. Boundaries

To understand the site’s layout, the survey will include information about kerbs, walls, fences, railings, and gates and is essential for, drainage planning, and accessibility considerations. This information also assists construction and property managers to layout sites, plan considerations and identify legal boundaries.

8. Excavation scars

Any visible excavation scars on the site are included in the topographic survey. These scars provide valuable information for construction and project managers regarding previous site activities, buried utilities, or potential hazards during construction.

9. Vegetation, hedges and trees

If specified the topographic survey will map vegetation, including trees with a diameter above 100mm. This helps architects make informed decisions regarding the preservation or removal of vegetation, landscape design, tree preservation, and ecological/environmental impact assessments.

10. Headwalls and water features

For drainage systems, the survey includes headwalls, indicating the pipe diameter and invert level. If there are definable edges of water on the site, the topographic survey will accurately represent these features and include water levels where relevant to ensure the accessible areas are noted. This information assists environmental consultants and property managers in designing drainage systems, floodplain analysis, preventing flooding/waterlogging issues and environmental impact assessments.

11. Furniture, road markings, car parking spaces and crossings

If required the survey can include site furniture such as bollards, telegraph poles, lampposts, signage, barriers, road markings such as give way signs, lane dividers, mini roundabouts, layout and marking of car parking spaces, including designated spaces for disabled individuals and parents/toddlers, and type of pedestrian crossings. This information facilitates civil engineers and urban planners with site planning, traffic management, safety considerations, parking design, accessibility planning, and traffic flow management.

12. Changes in surface materials

Any changes in surface materials, such as pavement or flooring transitions, the presence and details of steps, stairs, and ramps (including rise/going information and direction) is mapped on the topographic survey. This information assists designs for accessibility planning, coordination with architectural designs, and construction safety considerations.

13. Site survey orientation

The site survey drawing is oriented to the OS National Grid and Newlyn Datum, ensuring consistency in spatial reference and alignment with other mapping systems. This facilitates data integration and supports subsequent surveys and monitoring, promoting effective communication and collaboration among project stakeholders.

Optimising Plans and Designs with a Topographic Survey

By including the essential elements discussed above in a topographic survey, construction professionals can effectively analyse and plan site development, understand existing conditions, and mitigate potential challenges. Architects can create accurate and well-informed designs, considering the existing context and meeting the needs of their clients and the surrounding environment.

Property managers use topographic surveys in their asset information models (AIM) and digital information management systems (DIMS) to plan landscapes and drainage systems, for construction and renovation projects to align with the as-built existing designs and for estate management to understand property boundaries. With accurate and detailed information at hand, project teams can optimise their designs, streamline architectural and construction processes, and deliver high-quality results.

CADS Topographic Survey Team: Qualified and Experienced

CADS topographic survey team is qualified in BSc Geomatics and Surveying Engineering and BSc in Building Surveying, hold CITB CSCS and DBS cards and is experienced in major multiple site survey programs (buildings and land) for national UK retailers, banks and building societies. They have experience in large scale topographic land surveying on sites across the UK including the extensive measured building and topographic survey of Salisbury Maltings.

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