Dom Latham Ltd was commissioned by Torsion Group Limited to undertake a multi-disciplinary survey project at Hipperholme Grammar School in Halifax. The site had been acquired for re-development and one of the overriding factors in being successfully chosen to undertake the work was our ability to provide all the required survey services in house.
The project specification was as follows: Full underground services stats records search and report. Topographical survey. Underground utility mapping survey conforming to BSI PAS128 specification. Full internal measured building survey.
All statutory undertakers were contacted requesting detailed information to be provided for any service present within the survey area. Returns for affected and unaffected services were compiled in the stats report and issued to the client well in advance of the rest of the survey deliverables.
GNSS observations were taken to establish the site survey control relative to Ordnance Survey National Grid & Datum. A high order survey control traverse was established around the site and observed using multiple dual face readings using a Topcon DS103 3” total station. The traverse misclosure was in excess of 1 in 100 000.
Topographical detail was then observed using our in house field coding system and the survey was processed using SCC before final export to AutoCAD. Final adjusted survey control computed in the SCC project:
Editing the topographical survey model in SCC:
The topographical survey was delivered to the client prior to the next phase of the work to keep the working deliverables flowing.
A full underground utility mapping survey to PAS128 specification was then undertaken using all available techniques and utilising the stats records report as a starting point. Each detectable service was surveyed by independent methods (EML & GPR) to yield the highest confidence in the survey results. Findings were then surveyed by total station and overlaid onto the topographical survey drawing to provide the final results.
Part of the final topographical and underground services CAD model:
A section of the drawing titlebox explaining the different PAS128 quality levels:
Further drawing titlebox details:
Once again survey deliverables were issued so that information could be continually issued to the clients’ design team.
The final phase of the project involved a full internal measured building survey over all floors. The Grammar School building dated from the early 1900’s and consisted of basement, ground and first floors. The external building footprint was carefully surveyed as part of the topographical survey, and the survey control was extended into the building so that each floor could be surveyed by fully connected techniques (plan and height position is related to the external survey control and the building surveyed internally by instrumental methods only). Similar to the topo survey the MBS data was captured and recorded to our data loggers using our in house building survey coding system.
Internal measured building survey results – ground floor:
Internal measured building survey results – first floor:
The final deliverables were made with everything to the clients’ satisfaction. This project clearly demonstrates the advantages of being able to undertake all of the survey elements ‘in house’, as each stage is complemented by the previous work; minimising any errors and removing the communication difficulties which can occur when separate contractors are employed for each individual task. Moreover the survey deliverables are streamlined which is highly beneficial to the client.
All work is carried out to the RICS professional guidance, global, Measured surveys of land, buildings and utilities 3rd Edition; undertaken to RICS terms and conditions of contract for land surveying services, 3rd Edition (2009).