Handheld scanning takes survey of heritage building to the next level


Handheld scanners have allowed a site team to deliver as-built representations of an art deco skyscraper in Belo Horizonte, Brazil, four times faster than traditional methods

Location: Belo Horizonte, Brazil.

Project team: Paragram Architecture &

Consulting, Criar Projetos E Consultoria.

Completion: 2019

Almost every complex building or renovation project is subject to strict time constraints. A major upgrade to a 130-metre art deco skyscraper in Brazil was no exception. Located in Belo Horizonte, the country’s sixth-largest city and the capital of the south-eastern Minas Gerais state, the Acaiaca Building dates back to 1943 – and was built with an air raid shelter.

The art deco-inspired design by architect Luiz Pinto Coelho features two huge carvings in honour of the tribe from which the building takes its name, based on legends of the tribe’s great strength and power. Over the years, the Acaiaca Building has been used as a nightclub, cinema and shops but today houses offices and a church.

Belo Horizonte-based Paragram Architecture & Consulting combines architecture, IT and project management with BIM processes. Ahead of a retrofit of the building’s electrical installations and fire prevention plan, the firm was commissioned to produce as-built architectural 3D drawings of the 32-floor structure.

Working alongside contractor Criar Projetos E Consultoria, Paragram opted to use GeoSLAM’s ZEB-REVO, a lightweight mobile mapping device that can be operated simply by walking around.

First steps

Paragram initially planned to measure the 8,357 sq m building using manual survey methods – a task that would have taken a team of three employees more than 40 hours to complete.

Despite the scale of the project, the survey team was ready to use laser tape and paper to document the as-built structure but switched the handheld scanning method. Powered by SLAM (Simultaneous Localisation and Mapping) technology, it can rapidly generate images to within a few centimetres of accuracy, even indoors where there is no GPS.

This approach could significantly reduce the projected 40 hours to less than 20 minutes to survey each floor, or around 10 hours in total.

Off the ground

handheld scanners, Belo Horizonte, BIM,When the project got underway, the handheld scanner was programmed to achieve the maximum consecutive levels in under 20 minutes, with minimal overlap between each shot.

The team used the hallway of the stairs and elevator for the starting point of each scan, which provided a clear reference to align the point clouds.

It took two operatives just 10 hours to complete a scan of the building’s interior, with one handheld scanning and the other taking a photographic record.


As well as delivering on speed, the project team was impressed by the accuracy and ease-of-use of the ZEB-REVO.

Jose Vargas, BIM technology consultant at Paragram Architecture & Consulting, said: “We were able to gather much more information than first anticipated, such as the registration of beams, roof trusses and other structures, as well as a detailed survey of exposed electrical installations and engine rooms in areas that would have been very difficult – not to mention time-consuming – to access.

“What really stood out was the quality of information captured, which was easily incorporated into a BIM representation using Revit software.

“The device was really easy to handle and it was remarkable how much detail we were able to capture in the point clouds. It enabled us to achieve a level of accuracy that would have been impossible using manual surveying techniques.”

Futureproofing the Acaiaca Building

The distinctive style of the Acaiaca Building, famous for its carved figures on the side, has made it a much-loved part of Belo Horizonte’s skyline.

All heritage buildings need to undergo modernisation work during their lifecycle to preserve them for generations to come and for the Acaiaca Building, this is an example of how an asset can evolve to meet the demands of current and future users when owners are prepared to make the necessary investments.



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