We know one of the very costly aspects of a renovation and retrofit project is the occurrence of errors due to insufficient knowledge of existing conditions of a building and its infrastructure. When we were asked by Dalmark Development Group, LLC to provide a 3D Revit building information model (BIM) of the existing conditions of the Attucks building, we knew BIM scanning could provide the information they needed.
The Attucks building, constructed in 1905, was designed by Kansas City architect Charles A. Smith, is listed on the national and state historical registers, and is significant for its role in the education history of the African-American community in Kansas City. With such a historic building, there are bound to be unforeseen existing conditions that could add up very quickly. With the use of BIM generated from scanning, our goal was to distinguish those problems at the beginning of the project thus saving our customer time and money.
Here are a few key benefits to a project owner from a BIM project:
- Provides analysis of building systems, alternative materials, equipment, and technologies which leads to more informed decision-making.
- Identifies constructability conflicts.
- Reduces overall project delivery times for design and construction.
- Facilitates the analysis of sustainable design alternatives and cost comparisons.
Our Strategy and Technology
Existing site conditions presented some unique challenges. We faced the challenges head-on with our no-problem approach by combining innovative use of technology and some workflow integration. This strategy improved project safety and saved approximately two weeks of field time.
While our main focus was safety of personnel doing the indoor measurements, we overcame structural and air quality issues including: visible deterioration in the wood floorings, ceiling collapses, and air quality conditions (asbestos particulate matter) by combining Leica P-40 and ZEB-REVO scanning systems.
A detailed control system of coordinates were established to provide accurate control for the 3D scanning process. For the building exterior, we selected the Leica P-40 scanner do to its high accuracy and point acquisition rate. This process involved approximately 25 setups all acquired in one day of scanning, and included several “key” interior scans for follow-on registration.
Building Interior Technology
For the building interior we chose the new GeoSLAM ZEB-REVO hand-held mobile mapping scanner using 3D SLAM technology, but what does this mean?
Simultaneous Localisation and Mapping (SLAM) technology was born in the robotics industry and is used by autonomous vehicles to concurrently map and navigate through an unknown environment. To do this SLAM algorithm utilise information from sensors (often LiDAR or imagery) to compute a best estimate of the devices location and a map of the environment around it.
Why is it Important? SLAM algorithms provide a way for a sensor to measure a building or environment, while simultaneously locating itself. All of this work is performed on-the-fly with no previous location information required. Because of this, SLAM algorithms are ideal for applications where GPS or survey control are unavailable or unreliable. When compared to traditional survey methods for measuring indoors, such as tape and disto, or static laser scanners, mobile indoor mapping is proven to be up to 10 times faster.
Tying it all together
The building was modeled using a combination of data collected from a Leica P40 and ZEB-REVO scanners. Cyclone 9.1.4 provided the ability to effectively register both data sets to a common coordinate system and export to Autodesk ReCap as a. pts file format. We divided data into 10 GB files for efficient use in ReCap and Revit 2014, where a level 200 BIM model was created. The model documented basic architectural and structural components of the building’s interior and exterior.
With our part of the project wrapped up, the Jazz District Redevelopment Corporation (JDRC) is studying the structural integrity and space utilization of the building for consideration as a community performing arts center and for office space. If constructed, the proposed performing arts and office space will contribute to the 18th and Vine Historic District in Kansas City, which earned the name, “Jazz District” during the period from 1920 to 1940 when it became the center of jazz music.