TL/DR: Using maps generated from Skyview, the construction team was able to catch costly and time consuming mistakes. Using these maps, even on a small scale project, the owner saved months of redesign and coordination and easily 10x the cost of the imagery service.
Case Study: Parking Lot Construction
We're at about the midway point now for the construction of a new parking lot in the North part of Austin with Blue Construction. We've incorporated Skyview UAV maps and imagery into our project management toolbox. Here are some observations on how we were able to leverage the information collected to benefit of the project.
- Preconstruction site evaluation.
Before we submitted the RFP to general contractors to bid on the project, Skyview generated a 2d map of the job site. This gave us all context of the site; where contractors could park, where they had to set up erosion control and silt fences, preliminary analysis of phasing and road closures, and laydown yards.
Most importantly, we were able to avoid a costly change order. It was discovered between when the permit was signed and when we started construction Austin Energy had installed a power pole. It appeared to be directly in the middle of the driveway. The construction team was trying to estimate by eyeballing where it would hit based on the set of plans, but we wouldn't be able to know for sure unless we did a survey. A surveyor would take weeks to organize and cost hundreds, maybe thousands of dollars; at that point we didn't have a contract vehicle to even consider charging that expense against.
The potential impact of this oversight was substantial- weeks of redesign with the engineer to relocate the driveway, resubmit to the City for a site plan correction, a costly change order with the contractor, and weeks of delays. Alternatively, we would have had to coordinate with the City of Austin to relocate their power pole, which again could take weeks and months to do.
Thankfully, we had generated a map with Skyview. We were able to overlay the imagery with a site plan, identify where the driveway was going to go, and were able to quickly identify we had approximately 22" of separation between the curb and power pole. Austin Energy agreed to allow us to build if we installed bollards. The impact to the project was minimal, it saved us thousands of dollars and easily weeks and months to the project schedule.
- Formwork, pre-pour inspection.
The utilities were not too extensive on this project, but there was a lot of discussion regarding the reinforcement of the concrete pads. Rebar placement, how the curbs were to be poured, and expansion joints.
Mapping the pad, before and after the pour, we were able to confirm with the construction team everything was located in the right spot, the reinforcement plan was sound, and the expansion joints were adequately spaced.
After the pour, we were able to verify using the elevation maps the pad was draining in the right direction and verified at the time of the pour there were no low spots for pooling.
- Phased construction planning.
The 2nd phase of the project was to redo the driveway into the parking lot. Articulating this to owners was verbal, which opens up a lot to interpretation on where employees could and could not walk and park. The ability to communicate with the team and demonstrate graphically where the construction was to take place simplified the process.
- Area, volume estimations.
The information collected was shared with the subcontractors. We discussed additional services to resurface the back parking lot while we were mobilized. We were able to make distance/area/volume calculations quickly and accurately to do take offs for additional pours and phasing, otherwise requiring more crude and inaccurate collection methods.
Despite being a small project, we were able to find efficiencies in our process to make the project run more smoothly, communicate information to the whole team, and directly save time and money to the owner.