Aerial Imagery + Software for Roofing Quotes

By Ray Smith, Founder / Managing Director, AppliCad

Okay guys, let’s get something straight out of the box. In general, satellite images do not have the resolution high enough to boot accurate material. Hmm, that’s a big statement since everyone wants to use “satellite images” for estimates. The problem is, you can’t improve the resolution of an image, much like you can’t remove a tree that overhangs and covers half of the roof, making it impossible to extract a usable dimension. This limitation is a function of resolution or image quality, and satellite images are generally not as high resolution as aerial photographs from specialized research aircraft. Relying on satellite images cannot solve these problems; instead, you should use the information provided and make the best of it. Sometimes you have to drive away and measure one on the spot.

Most services that use imagery for estimations typically use aerial images taken by airplanes at relatively low altitudes (compared to satellites). This produces more accurate images that can be used to get started and from which to prepare a customer proposal. However, depending on your roofing material, you will always have the clause “Subject to confirmation by on-site inspection” printed in bold on the quotation. You must keep in mind that an estimate is not a material start – just ask a large-scale surveyor who takes pride in his craft.

Not all roof coverings can benefit from the use of aerial photographs. The most obvious, of course, is new construction, so as most of your job is new build, you work according to architectural plans (usually a PDF document that you receive via email or downloaded from a file-sharing site). In this case, you need a program that can use the PDF as a guide to recreate the roof geometry so that a detailed material recording can be extracted. 3D CAD based software is the best solution because it has the built-in tools necessary to ensure accuracy and repeatability using images, PDFs or field measurements.

If you are using smaller sized roofing products such as shingles, tile or slate, taking off from an aerial view usually works well. This is generally made possible by the fact that unused material can be returned to your supplier for credit towards the next job. Keep in mind that if your quote contains a lot of material that is then not used, you run the risk of overpaying prices and missing jobs because you are too expensive. Instead, it’s better to use tools that can help you create a quote for the job that’s reliable and just right every time. Good software helps with this.

Sample report of roofing estimate based on aerial photos

If a lot of your work is metal roofing or you plan to install a metal roofing then the only place for quotes generated from aerial photos (satellite or aircraft) is to get your foot in the door . Your quote is always “Subject to confirmation by on-site inspection”. In my experience, there are no aerial photographs that are accurate enough to make an accurate metal roof cutting list.

Having said this, quote software is still an extremely valuable tool, especially if you want to receive a ton of quotes – the more quotes that are submitted, the more likely you are to bring in new work. However, this is not productive if you have to spend hours on end visiting locations to measure each task. You should try to collect as many quotes as possible, “Subject to confirmation by on-site inspection.” When the job is confirmed and the deposit is paid, visit the site to confirm the exact requirements.

With the right software tools, I know it is possible to delete 10 to 15 residential quotes per day using aerial photos.

There is one caveat to these comments for guys with metal roofing: it depends how you work. Some contractors order their metal roof panels from a manufacturer who manufactures them off-site. In this case, the cut list should be perfect and with the right software it can be achieved. Other roofers have portable roll formers and fabricate the panels on site, simplifying the quotation process. As long as you order enough spool, you don’t have to be that accurate on takeoff – just order the right amount of spool. Again, good software tools will help with this and make sure you don’t have excessive waste.

Metal roofers need not only accurate information to win the job, but also accurate information so that you have the right materials at the job site (not only the panels, but also the clips, screws, sealants, underlayment, etc.). This makes the job easier to install, results in minimal waste and helps you make a nice profit. Software can help roofers achieve all of these goals by creating the most accurate panel layout on a 3D model of the roof, optimizing the reuse of scrap (if applicable) and specifying every single nut, bolt and screw, all from within the 3D model. It will even account for the gutter overhang. This is an important aspect that will benefit you from using such software – a detailed quote isn’t just panels, it’s everything else that comes with a job: fasteners, clips, ledges, hips, troughs, gutters, drip edges, downspouts, sealant, insulation, underlayment, penetrations, boots, flashes, maybe even solar panels… This specialized software does a complete job based on how each item of inventory is delivered and used. If you need 112 special clips, you will get 112 special clips.

Meanwhile someone will shout: “What about drones?” Well, they are just another source of aerial photos from an ‘airplane’. However, beware: drones have their own issues if you want to use them to aid in citing. The first and most obvious is the fact that you now have to do another site visit and with the installation etc. you can only do a few jobs a day. The real problem with drone imagery is more insidious – something you sneak up on if you’re not paying attention – parallax error. To fit the entire property into the shot and not fly so high that the FAA comes to visit, the cameras on most drones have a very wide-angle lens. This lens can transform a square roof into a “cushion” shape. If you do not get enough height to take the photo of your roof, the edges will not be square and this will compromise the dimensions that will recreate the roof model that you will use to extract your bill of materials and quotation.

To be clear, if you quote jobs by raising your thumb and quoting “X” dollars per square, labor and material, then nothing I’m saying here matters. If you are looking for fair, accurate, reliable and repeatable quotes that improve your business reputation, you need the best software tools and understand the shortcomings of any process you use to generate the quote.

Integration with portable roll forming machines

AppliCad’s Roof Wizard program not only generates a panel cut list for all panels, trim and accessories so that your quote is perfect, it also has an export option so you can pass the panel cut list directly to your roll former controller (although you must have the correct controller) , speeding up the process and removing transcription errors. In fact, we’ve been doing this in Australia and New Zealand for over 20 years, so it’s not a new idea. It is a well tested and proven process that improves accuracy and reliability for you and your customers.

If you have any questions, drop me a line: [email protected] RT

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