Challenge

1 Lothbury lies in the heart of the City of London’s financial district and plays home to Bank of China’s UK Headquarters. Our client BWA, a Chartered Surveyors firm that specialises in independent consultancy for financial and management aspects related to land, buildings, and facilities services, required the creation of as-built floor plans and an area reference report. The surveys needed to accurately determine the building’s gross internal area (GIA) and net internal area (NIA) for property valuation and facility management purposes.

The structure, a 12-story office building in the City, has undergone significant architectural redevelopment in recent years, featuring a completely new construction behind the original Portland stone facade, which was carefully dismantled and reassembled.

02 bank of china measured building survey

Approach

Access to various areas of the building were limited depending on usage and weekday vs weekend, so a flexible approach to timings and adapting measurement techniques was offered.

The site inspection commenced with an external survey of the building’s facades using 3D laser scanning. Black and white scans set to medium resolution were selected, allowing us to capture approximately 2 million points per second, with a 1mm density.

Opting to connect an iPad via Bluetooth to the scanner also gave access to a broader array of settings allowing the team to assess the quality and completeness of the data capture, ensuring no part of the survey was left unrecorded.

Surveys were carried out across the 12 floors on a floor-by-floor basis for efficiency, commencing with the basement and working our way to the roof terrace.

Outcome

Over 1,000 individual scans had been completed by the conclusion of the survey, resulting in a total of 2 billion 3D points.

The uploaded data was processed using Leica Cyclone, a leading registering software. The software helps to accurately review, analyse, align, consolidate, and register the data captured by each scanning location into a single point cloud, looking for either geo-referenced scan data or areas with overlapping details.

The survey did not require referencing the Ordnance Survey National Grid, so a local arbitrary datum was assigned to the survey and our in-house quality control team ensured standards met band E of the “Survey accuracy band table” from RICS “Measured Surveys of Land, Buildings and Utilities, 3rd edition”.

We identified any walls, columns, and other structural elements, followed by void areas over stairs and atriums, as well as core areas that encompassed facilities like restrooms, elevators, mechanical rooms, and others. Calculations were performed resulting in Gross Internal Area (GIA) and Net Internal Area (NIA).

Through a comprehensive client care and quality assurance framework, the highest level of accuracy and precision allowed us to successfully deliver the survey of 1 Lothbury on schedule and within budget providing accurate and reliable data on the building’s area.

This information is crucial for various stakeholders, including property owners, investors, and facility managers in making informed decisions regarding the building’s utilisation, valuation, and future development.