About This ProjectDublin City Council wanted to develop a scheme for the Parnell Square Cultural Quarter redevelopment which would involve the whole city block. It currently consists of many old listed and non listed buildings squeezed in and around each other, with newer buildings that interact with this. Simply understanding the space and scale of the site was a challenge, as well as recording every feature for conservation and heritage. BIM was seen as key to understanding this site and delivering a more efficient, complete design. We provided laser scanning of the site, traditional CAD information, high quality photography and BIM models of the complete site and surrounds, with all information linked in to the same single BIM model
We enabled the high quality 360 degree photography taken at every laser scanner location to be incorporated into the model at the same locations. A single click can bring up the bubble views of the imagery enabling panning and zooming of the relevant space to view high quality imagery of the space. This enables quicker gathering of information from a single source in one model space.
No software is actually needed to view any of this as both the model and 360 photography are uploaded online to be shared and viewed on a web browser only. All model properties are viewable and sections can be cut and customised here, while clicking on the photo links directs to the photography stored online also. For easier collaboration and to overcome software issues, Murphy Surveys have developed an Online Web Portal for sharing BIM, CAD, point clouds, imagery and animations with mark up features.
The whole site proved challenging to get access at appropriate times. Many areas were off limits or were extremely difficult to get access to, while other areas were hard to physically survey, such as rooftops, due to poor access, dangerous conditions on the rooftops and poor stability for laser scanner tripod set up. Unprotected edge and parapets made it difficult to survey certain roof faces while moving between properties on rooftops became hazardous. So many of the adjacent buildings had different access requirements, and this resulted in many trips back to site, and delays in gathering relevant survey data for such areas.
The nature of BIM is consistent objects and cost efficiency, so a heritage site whereby every second floor is sagging far beyond the desired model tolerances, in excess of 120mm in many cases, demands a customised approach. This approach meant that rather than simply noting the deviation in parameters, we were aware that many other subcontractors would use our data, so such floors were modelled efficiently but to the main deviation areas, while other minor deviations were noted in comments alongside.
Often such surface accuracy would be only possible using other 3D modelling software and imported into a BIM environment, however this results in less functionality. It allowed us to maintain the connections and visibility of native BIM objects with associated notes and comments available for data extraction, scheduling and filtered views while CAD based sub contractors are still able to use our data in an improved manner than if we followed standard BIM modelling practices.
Other challenges involved the staggering natures of the project site. Varying levels and adjacent constructions were to be modelled and set up in plans and sections in one building file originally. However, this was revised once the nature of the site was better understood and captured in the laser scans. Individual building pairs were created that were logically connected together and could be turned on or off in a site file. Care was taken to not divide the site into too many components as to become confusing when linked into other projects or for documentation purposes.
Advantages of BIM
- The ability to incorporate heritage notes and document links to the relevant parts of the model
- Custom parameters and schedules can be created within the model allowing notes and documents to be tracked, filtered, automatically generated and quickly accessible. It allows both graphical and metadata (identity, material, physical, etc) to be shown in the same file
- Quantifies objects quickly for repair and maintenance, tracking, sequencing of demolished and/or development areas and objects
- Carry out visualisation and marketing within the model, which can be exported for further marketing refinements and visualisations to other software
- By utilising BIM we can maintain the links for attaching the ‘point in time’ laser scans to the models
- This image shows a colour scan linked to the model, visible in this 3D section and any other views for comparisons to be made with the model
- Future scans can be linked in anytime to compare different laser scans at many points in times which show up instantly in any section or views already existing in the model so no further drawing is needed
Laser Scanning, BIM, Photographic Survey, Topographic Survey
IFC and Revit Models, High quality Laser scan files, photographs and condition reports, animations, renderings.