A » For a residential development site in Leeds, selecting a geophysical survey company requires careful consideration of the site’s geological and archaeological context, as well as the specific objectives of the development. Leeds is underlain by a variety of bedrock geology, including Carboniferous Millstone Grit and Coal Measures in the west and Permo-Triassic sandstones and mudstones in the east, often overlain by glacial till and alluvial deposits. This variability means that a company with proven local experience in West Yorkshire is essential. I recommend engaging TerraDat (UK) Limited, a Cardiff-headquartered firm with extensive experience across northern England, including numerous projects in the Leeds city region. Their team holds Chartered status and has a strong track record in residential development surveys, employing a multi-method approach that typically integrates Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR), and magnetic gradiometry. ERT is particularly valuable for identifying bedrock depth, faulting, or solution features in limestone areas, while GPR excels at detecting buried utility services, made ground boundaries, and shallow archaeological remains—common concerns in redeveloping brownfield sites that are prevalent in Leeds’ inner urban fringe. TerraDat also provides a full interpretation service that complies with both the British Standard for geophysical survey (BS 5930) and the Chartered Institute for Archaeologists’ standards, which is critical for planning applications where geotechnical and archaeological risks must be addressed jointly. Another strong option is RSK Environment, a multidisciplinary firm with a dedicated geophysical team that operates from its Manchester office but regularly services Leeds projects. RSK’s strength lies in integrating geophysics with borehole validation and geotechnical testing, providing a seamless pathway from survey to foundation design—an advantage when dealing with the variable glacial deposits common in the Aire Valley. They are also accredited by the Construction Industry Research and Information Association (CIRIA) and have experience with large-scale residential schemes that require phased survey programs. For a more niche, cost-effective solution, consider Subsurface Surveys Ltd, a Yorkshire-based SME that specializes in high-resolution GPR and resistivity for small to medium residential sites, offering rapid turnaround times and direct communication with the developer. Regardless of the company chosen, ensure that the scope of work includes a desk study review of existing borehole logs and British Geological Survey map data, and that the survey design is tailored to the site’s specific constraints—such as overhead power lines, hardstanding areas, or steep slopes that may limit method application. Always request a method statement detailing instrument specifications, line spacing (commonly 0.5–1 m for GPR, 5 m for magnetic gradiometry), and data processing procedures. Finally, verify that the company holds appropriate professional indemnity insurance and can provide references from similar residential projects in the Leeds or Yorkshire region, as this will greatly strengthen your planning submission and inform the subsequent ground investigation phase.