Drones for construction

Drones for construction

Aerial drone data can deliver valuable insights during every phase, from preconstruction bids to site handoff.  With up to 30% of the cost of construction wasted in the field due to coordination errors, wasted material, and rework, your drone can be the solution to a Production Manager’s problems-if you know what to offer.  Here’s my take.

Progress Photos

One of the easiest items to capture and deliver, progress photos allow greater visibility into a quickly-developing construction site at a relatively low cost.  The key is to deliver photos from the same angles and altitudes each time so that clients can easily recognize specific progress each time.  While this may seem easy to accomplish, using programmed flight routes and angles can be dangerous with constantly-changing site altitudes and crane heights and positions.  In addition to the photos, I’ve found that clients appreciate a document that compares one week to the next utilizing photos from specific angles and altitudes.  Be sure to include shots of any new progress, perceived problem areas and especially anything the client mentions that may have been a challenge. (You’ll pick this up in your pre-mission visit to the trailer before your flights.) 

 

Video

There’s nothing like a simple edited video to excite the client.  Chances are, you’ll be hired by the construction company and they’ll show your stuff to the owner.  Owners may not make it to the site often, and a video keeps them engaged with their “baby” as building progresses. It’s your job to make things look good-especially in the early stages when there’s not much going on.  Remember-Cinematography “Rules” Still Apply!  Keep your shutter speed 2x the frame rate for smooth video.  Find some foreground to move past to add visual interest to the shots.  Use shots that “reveal” other information from the side and from the top.  “Rise-Up” and “Ped-Down” shots of buildings allow viewers to capture different angles of the site without getting bored.  And, most importantly, automate your orbits.  While most construction clients are very forgiving when it comes to shot stability, you’re a professional and they’ll appreciate stable, well-composed and exposed shots. 

Orthomosaics

“Orthos” are made by collecting hundreds of photos in a pre-planned pattern and altitude then using software to “stitch” them together into one high-resolution image.  It’s like an up-to-date Google map that’s super high resolution.  These offer a high-level look at the entire site without having to leave the office or trailer.  Benefits include: Import capability  into industry software like BIM, GIS and CAD for more advanced oversight and planning; Foundation documentation: Pre-pour documentation of what’s inside slabs, the quality of rebar install and post-tensioning cables;  Façade/structure inspections with no scaffolding, and Crane inspections with no lock-out/tag-out;  Landscaping insight on water reach, drainage, final grading and landscape features; and documenting “As Built” condition before handoff.

Volume Report

Volume Report

Volume Calculations

One of the most useful measurements for the amount of work involved, Volume Calculations give your client a simple way to measure how much dirt or material is in a given pile-keeping inventory and off-haul costs accurate.  Earthpile Volumes and Stockpile Counts can be calculated with no ground control or benchmarks simply by using parallax, or the offset between photos of the same image in your Orthomosaic.  Most stitching software is able to calculate volumes automatically-make sure yours is among those that does.

Overlay Example

Overlay Example

Overlays

This is when an architect’s or developer’s plan is superimposed onto an orthomosaic of the site.  For this you’re dependent on your client to provide the plans, but once they know if the value, you’ll have no problem getting them. Overlays are helpful in a number of ways including: Helping to reduce rework for utility pathways and documenting in-ground utilities; Visually showing position of site plans for utility, runoff and equipment clearances on the actual site as it develops and comparing real-time site conditions against the plans.  This can help the client catch conflicts early and correct them before they become big problems later.

Contours

Contours are the elevations throughout the site expressed as “lines” that connect same elevations giving a visual representation of site elevations at different locations.  If you’re a hiker and have used contour maps, these are the same, except specific to the site you’ve flown.  Contour measurements allow for more active and competitive pre-bids and accurate site balancing for final grading.  To calculate contours, you must lay ground control points and fly a precision mission, so this is more of an add-on feature than a basic offering item since time and effort is increased dramatically when flying precision flights.  More on precision flights and ground control in a later blog post.

Drones for construction

Drones for construction

Remember-it’s your job to communicate what you can do for them and how it’s going to help.  Don’t assume Project Managers and Supers know the benefits of drone flights over their site.  Many think of them as a nuisance, and unless you can show otherwise, you won’t be invited in.  If, however, you can show them how to save time, money and make them look good to their boss, you will have gone a long way towards securing work with them now and in the future.