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Building Science

Patent Troll Wins First Case Over Use of Infrared Cameras

A Mississippi company with patents covering the thermal imaging of homes is targeting home inspectors and energy auditors

Image 1 of 4
“Patent troll” is a pejorative term used to describe a person or company that enforces its patents against one or more alleged infringers in a manner considered unduly aggressive or opportunistic, often with no intention to manufacture or market the patented invention. (Definition from Wikipedia)
Image Credit: kewl,
“Patent troll” is a pejorative term used to describe a person or company that enforces its patents against one or more alleged infringers in a manner considered unduly aggressive or opportunistic, often with no intention to manufacture or market the patented invention. (Definition from Wikipedia)
Image Credit: kewl, Fig. 2. HomeSafe's patented apparatus for mounting an infrared camera and a digital video recorder on a harness.
Image Credit: HomeSafe Inspection, Inc.
Fig. 3. Alternate version of HomeSafe's patented apparatus, this one holding only one camera since the technology combining the two functions described in their patent already existed.
Image Credit: HomeSafe Inspection, Inc.
Patent trolls are dragging down innovators.
Image Credit: Application Developers Alliance

A year or two ago, I remember getting trapped in my car one evening listening to Ira Glass’s show This American Life. It was an episode titled When Patents Attack, and I was riveted. The show described how a seemingly small change in the U.S. patent office’s protocol led to the growth of an industry that siphons money from tech companies through legal, but sketchy, license fees and lawsuits.

It seems that some in our industry were paying attention to Nathan Myhrvold’s shenanigans and are now going after home inspectors and energy auditors.

HomeSafe Inspection, Inc. files a lawsuit

HomeSafe Inspection, a Mississippi company that has several patents covering various uses of infrared cameras, filed a lawsuit against Assured Home Inspections of Tupelo, Mississippi, and its owner, Charles Russell. The company claimed that the defendant willfully and deliberately infringed on three of its patents (patent numbers 7,445,377 B2; 7,434,990 B2; and 7,369,955 B2).

The company has asked the court to:

  • Permanently shut down all of Mr. Russell’s business practices that it claims infringe on its patents;
  • Grant damages for the alleged patent infringements;
  • Grant enhanced damages for the infringement being willful;
  • Let the plaintiff collect interest and costs, pre-judgment and post-judgment;
  • Award the recovery of attorneys’ fees; and
  • Give the plaintiff “such other and further relief” that the court finds reasonable and fair.

You can download and read a copy of the lawsuit yourself. The lawsuit itself is only five pages long, followed by the full text of the three patents cited.

Last Wednesday brought an interesting new development to this case, a development that likely will only make things worse for home inspectors and energy auditors. Before we get into that, though, let’s take a look at the substance of HomeSafe’s patents.

The slippery slope of what qualifies for a patent

One of the things I learned in that episode of This American Life was that for a long time, the patent office resisted awarding patents to computer programs, in whole or part. Then they changed course in the 1990s. If someone figured out how to write a piece of code that did something like open a dialog box whenever you pop a CD into the drive, the patent office decided that piece of code deserved a patent.

I’m no expert on patent law or history, but it seems that patents used to go for inventions of real things, like light bulbs and carburetors. Patents could be awarded for processes, too, but those were industrial processes that led to real stuff you could touch, like Goodyear’s patent for vulcanizing rubber. They weren’t for obvious things like how to sell more apples from your cart.

What did HomeSafe claim to have invented in the three patents cited in the lawsuit? First, here are the titles along with the last three digits of their seven digit patent numbers, as HomeSafe abbreviated them in its lawsuit:

  • 377: Non-Destructive Residential Inspection Method and Apparatus
  • 990: Additional Methods to Detect Termite Infestation in a Structure
  • 955: Residential Indoor Environmental Quality Inspection Method

You can find the full text of all their patents online (just Google “patent number xxxxxxx” using the 3 patent numbers above), but let’s take a look at the details of the first one, 377. Here’s the abstract:

Abstract. This invention provides an apparatus for nondestructive residential inspection and various methods for using a thermal imaging apparatus coupled to inspect exterior residential components, interior residential components, a pitched roof and basement of a residential building and the electrical system of a residential building.

If you read through the entire patent, you’ll find that the apparatus referred to in the abstract is a harness for mounting an infrared camera along with a digital video camera (Fig. 2 below). They connect the two cameras with a cable to feed the IR signal to the digital video camera, but there’s nothing special about that connection. They don’t describe any proprietary technology or processes that make something possible that had never been done before.

The reason for that lack of detail is that cameras that combined those functions already existed when they filed for their patent. That’s why they included another version of the apparatus (Fig. 3 below) that held only one camera.

So the apparatus is simply a harness to mount cameras on, something that any handy person could build in their garage. HomeSafe hasn’t proposed any modifications to the infrared and digital video cameras themselves, and even the method of connecting them isn’t new. They just built a harness to allow home inspectors to walk around and keep their cameras steady.

Well then, what about their “various methods for using a thermal imaging apparatus”? Is there anything new and exciting to their methods? I’ve read through their whole patent number 377, and I couldn’t find anything that didn’t seem to be common knowledge in the thermal imaging industry.

The method they’ve obtained a patent for includes:

  • Creating a temperature difference of more than 10 F° by turning on the heating or cooling system
  • Turning on all or most of the light switches
  • Turning on all or most of the exhaust appliances
  • Using an infrared camera to get temperature profiles of the outside, inside, underside of the pitched roof, and each electrical outlet
  • Assessing the thermal images for thermal anomalies
  • Reporting the results (which they write in an odd way: “reporting said problem to said designated entity wherein said steps up to the step of assessing each of said profiles occur within 4 hours”)

The bulk of the text in the patent reads like a poorly written instruction manual for thermal imaging.

HomeSafe Inspection’s initial threats

HomeSafe applied for its patents around 2004 and got them in 2008, as I understand the timeline. It seems, though that they began harassing home inspectors before the patents were awarded. A recent notice from the American Society of Home Inspectors (ASHI) appeared on The Inspector’s Journal Online (see comment #19 by Kurt for full text) and gives a bit of background:

Around 2005 or 2006 HomeSafe began sending letters to home inspectors and energy auditors who use infrared cameras in evaluating homes, threatening legal action for patent infringement. HomeSafe claims, “It is impossible to perform a complete and accurate inspection or even a partial inspection with an infrared camera without utilizing HomeSafe’s patented methods and infringing.”

Additionally they allege, “If you are using an infrared camera to detect anomalies in a home related to indoor air quality, energy loss, moisture intrusion and electrical hazards among others, you are violating HomeSafe’s patents.”

After the early activity, HomeSafe dropped out of sight for a while. My guess is that they ran into more resistance than they expected and stepped back to make sure they had a solid legal strategy. Evidently, they believe they’re ready now.

A tale of two home inspector organizations

What actually happened last Wednesday, August 28, to make things worse? First, the good news: Mr. Russell doesn’t have to go to court. The bad news, though, according to the discussion at The Inspector’s Journal Online, is that Nick Gromicko, founder of International Association of Certified Home Inspectors (InterNACHI), paid HomeSafe a settlement to drop the lawsuit.

The ASHI notice put it this way:

In the meantime, the owner of the defendant’s home inspection association stepped in, before the court date for the defendant response on August 28, and offered to pay HomeSafe a cash settlement to drop the suit. While it might have been intended as a generous gesture, this offer and acceptance of cash provides HomeSafe a quick win and additional funds to file more legal action. This ill-advised payment to HomeSafe will further embolden them to pursue their legal strategy. In the end, while certainly a godsend for the inspector involved, this can mean more threats and more suits by HomeSafe against home inspectors.

I know the standard advice is to settle in these cases because patent holders have the law on their side. A friend of mine who’s a lawyer said his former company settled with the person who claims to have the patent for inventing “Press 1 for customer service. Press 2 to access your account…” Microsoft, AT&T, Sprint, and ConEd also settled, according to my friend.

Still, home inspectors and energy auditors mostly aren’t making a whole lot of money, so HomeSafe is essentially trying to squeeze blood from a turnip. It seems to me that they’re more likely to kill the whole residential thermal imaging business than to make enough money even to pay off their lawyers.

Who will HomeSafe attack next?

Surely HomeSafe must have its sights set on bigger game. I’m wondering if Fluke, Flir, and Testo, three of the big infrared camera makers, are their real target. Perhaps they’re going after the home inspectors and energy auditors first as a shot across the bow so the big companies with deep pockets will pony up some cash just to keep the market from dying.

I’m also wondering what the camera makers’ strategies are on this issue. They can’t ignore it any longer. Flir is the only one I’m aware of that has addressed the issue publicly. In a letter addressed to “Dear Valued Customer” dated 16 January 2009, they wrote that a person would have to carry out each part of the claims in a patent to be liable for infringement. They advised that, “Failure to practice even one feature allows a person to avoid infringement.” They closed the letter, however, with a paragraph warning that, “This letter should not be construed as legal advice.”

And then there are all the training organizations. Surely this has their attention. They’re teaching processes that are now covered by HomeSafe’s patents. For several of them, teaching how to use infrared cameras is all they do, so this puts them in a bad way.

It’s time for patent reform

Because of weakness in our patent laws and an underfunded patent office, a few people are siphoning a lot of money off the hard work of others. There’s some rumbling occurring in the tech industry about patent reform. The FTC is planning to investigate patent trolls. Also, Carbonite won a battle against a patent troll. People are getting fed up. John Poole of Birmingham Point posted the image of the patent troll and the innovator from the Application Developers Alliance on Facebook yesterday.

As a writer and educator, I’m all for protecting intellectual property. If someone creates something new, they should be able to claim their creation and profit from it. But the idea that someone can snap up a patent on something that people have been doing for decades is disturbing.

Apparently the formula for this easy money is easy to execute: Find a process that a lot of people are already making money from and patent it. In the forums discussing the HomeSafe issue, a few people have thrown out their ideas for patents:

  • “The method and/or approach of inspecting and/or looking at a house using your eyes.” ~ Bill Smith, in the RESNET BPI group on LinkedIn
  • “A method for consuming foodstuffs to sustain human life.” ~ David Meiland, in the RESNET BPI group on LinkedIn
  • “I’m about to file a patent on eating with a knife and fork and I’m very close to filing one on walking on the pavement.” ~ Flash, in the message board at the Infrared Training Center website

Clearly, those ideas are preposterous. No one could ever get away with patenting them. Could they?



Here I go again, putting myself out there, criticizing another company that could come after me just for speaking out. Was I libelous for mentioning patent trolls and HomeSafe in the same article? Have I “willfully and deliberately” harmed their licensing business by speaking out against their patent? Did I misinterpret something in their patent?

We’ll see what happens. It all worked out fine a couple of years ago when a much larger company came after me, though, so I think I’ll be OK.

Also, I have to tip my hat to David Butler, who brought this issue to my attention this past Labor Day weekend when he posted a discussion about it on LinkedIn. He gave a good summary of what has happened and included links to several of the places I quoted from and linked to above. Thanks, David!

And one final word: Please share this article far and wide. HomeSafe Inspection’s actions represent a threat not only to the home inspection and energy audit industry but also to any industry where someone could take a common technical process, write up a patent application in a way that the reviewers get snowed, and then send their lawyers out to start collecting the money.

For example, what if someone patented a process for commissioning HVAC systems? Or a particular remodeling technique like finishing an attic? Or a piece of computer code integral to energy modeling? I don’t think we’ve seen the end of this.

Allison Bailes of Decatur, Georgia, is a speaker, writer, energy consultant, RESNET-certified trainer, and the author of the Energy Vanguard Blog. You can follow him on Twitter at @EnergyVanguard.


  1. user-984364 | | #1

    And whatever you do ...
    ...don't scan a printed IR report and email it to a client. Then you'd owe someone else even more money.

  2. GBA Editor
    Allison A. Bailes III, PhD | | #2

    More nonsense
    Eric, I just read the article you linked to, and it seems very similar to the approach that HomeSafe is taking. Maybe their target isn't the big companies after all. Maybe they think they can get a bigger total by going after the end users.

  3. lindenboy | | #3

    Yeah, I listened to that episode of TAL as well. Amazing that this is being sanctioned by the very organization set up to protect legitimate intellectual property. I don't see how any of this stands up in the court of logic and reason, but hey, someone won a law suit with McDonald's for being burned by hot coffee. Stranger things have happened. I couldn't live with myself if this is how I had to make a living.

  4. user-1083454 | | #4

    Help me understand

    Good summary of the situation. The last bullet under "The method they've obtained a patent for includes:"

    Reporting the results (which they write in an odd way: “reporting said problem to said designated entity wherein said steps up to the step of assessing each of said profiles occur within 4 hours”)

    I'm reading this as "reporting said problem" = reporting what the IR found -
    "to said designated entity" = to the client
    "wherein said steps up to the step of assessing each of said profiles occur within 4 hours” = wherein the themographer assesses / evaluates each thermograph within 4 hours.
    Could that mean that if the thermographer waits to give any opinion or report their findings until 4 hours and 1 minute, he is OK???
    I'm sure it's not that simple, but what if?

  5. GBA Editor
    Allison A. Bailes III, PhD | | #5

    Response to Herb Scott
    That's what I wondered as soon as I saw that line, but I'm sure the lawyers wouldn't give anyone that easy a way out.

  6. user-984364 | | #6

    Smaller targets
    If you read the earlier Ars Technica article (linked to from the one I posted; it's at - it's a pretty good story) you see that yes, they are going after the small folks intentionally. They don't have the firepower to go after the Flukes and the FLIRs of the world - they actually have legal staff and might even overturn the patent. Go after the small guys instead, and collect $5000 here, $8000 there - it adds up!

  7. stuccofirst | | #7

    I don't think you can patent
    I don't think you can patent something so obvious as a method to use a tool invented by someone else.

  8. GBA Editor
    Martin Holladay | | #8

    Response to Shane Claflin
    You wrote, "I don't think you can patent something so obvious as a method to use a tool invented by someone else." Of course. That was Allison's point.

    These are the two problems: (a) The patent office shouldn't have issued these patents. (b) Litigation has gotten so expensive that, in effect, extortion has been legalized. Even when a small business knows that the troll doesn't have a legal leg to stand on, the business owner concludes that settling is cheaper than fighting in court. It really isn't any different from, "Give us $1,000 or Guido here will break your legs."

  9. GBA Editor
    Allison A. Bailes III, PhD | | #9

    Response to shane claflin
    Shane, the United States Patent and Trademark Office obviously disagrees with you, which is what makes this so dangerous.

  10. GBA Editor
    Allison A. Bailes III, PhD | | #10

    Guido's old tricks

    I wish I had thought of that! You've stated the main takeaways from this mess much better than I did. There is an important difference between what HomeSafe is doing and your scenario with Guido: This type of extortion is legal.

    [Edited to correct the name of the patent holder, which I had written backwards.]

  11. shtrum | | #11

    state weatherization programs
    It'll be interesting to see if HomeSafe plans to also go after the DOE and all the state weatherization programs. Each state program provides mandated training for IR cameras supposedly covered by these 'patents.' if HS went against these legal departments, they'd be toast. It looks like their plan instead is to go after smaller private outfits in litigation-happy states like Mississippi, and hope for quick payoffs.

  12. bjloden | | #12

    Don't Think You can Get a Patent...
    It has been a while since I've visited GBA, I think it was back in 2011 when I was leading ASHI's task force on this patent infringement issue. At that time we worked to build a coalition with the camera manufacturers, training companies and other organizations involved in residential IR. We also consulted with a number of patent attorneys around the country on the issue to determine the legitimacy of the claims and what courses of action were available. After a series of discussions it was decided to take a "wait and see" stance since the threats appeared to stop.
    Now that they have upped the ante with the filing of this action against Mr. Russell. We have now reactivated our task force and are working to develop the coalition necessary to deal with the issue. It will be important to develop a strong industry wide coalition that includes the entire industry including inspectors, energy auditors, water remediation specialist, and anyone else who might have occasion to turn on an IR camera inside a residence. We hope you will join us.

    If you think it is difficult to get a patent, go to Google and type in this patent number: US 6080436 A
    This is a patent for "A Bread Refreshing Method." You might be familiar with this process. It is commonly called "making toast."

  13. stuccofirst | | #13

    counter sue for harassment
    counter sue for harassment for such frivolous behavior. precedent needs to be set of which these sorts of things are not patentable. they are too obvious.

  14. GBA Editor
    Allison A. Bailes III, PhD | | #14

    ASHI spearheads the resistance
    Scott Warga from the American Society of Home Inspectors posted an update and an appeal in the comments for this article in the Energy Vanguard Blog.

    I am on the ASHI task force that is looking at this issue. I can assure you we are talking to the manufactures as well as the schools, we are also going to be contacting several others including RESNET and BPI. We are putting together a coalition to determine the best way to resolve this issue. We are also working with our lobbyist.

    This could cost a great sum of money and I'm sure the manufactures will be donating large sums, we will also allow individuals to make donations. If we could get every person that uses IR to donate $1-200 then we would have a pretty good war chest.

    After the battle is over and the smoke has cleared, any money left would be donated to charity so no one thinks any of the parties are making a profit off of this.

    ASHI tried to address this in 2011 but it stalled as the plaintiff had not filed a suit so the manufactures decided to wait. That has now changed so we are working on it again.

    Stay tuned, we will try to keep you informed.

    Scott Warga
    ASHI Vice President 2013

    1. Deleted | | #23


  15. heidner | | #15

    Prior Art - for the application goes back to the 1970's
    Look for the Princeton teams work at I believe the Twin Rivers project. They have infrared cameras setup to do house inspections looking for leaks and related problems. Track down those copies - if they get a letter from the trolls - have your lawyer let ASHI know and respond to the troll with prior art work letter.

    page 22 shows setup and example of leaky wall/ceiling... vintage 1974

    I am pretty sure if you go to the IR camera manufacturers from the early 1990's and look at their patents and application examples - that in addition to medical use... they will have examples in their publish commercial brochures of using their apparatus for building inspections.

    The patents listed made a feeble to go back prior to the early 2000's from what I saw - their patent search was very incomplete. -- it lacks a thorough investigation. The reference existing industry standards for residential testing with the camera's - but I didn't see any papers that would have been published during that era by the industries showing how to use the equipment for testing... their patent is about a process for testing -- and lots of prior art in the form of published papers already existed.

    The good news is that "patent" holders can probably sue their patent lawyers/researchers for malpractice in not doing their due diligence :-)

  16. gusfhb | | #16

    the patent fails for
    the patent fails for obviousness

    end of story

    It may also fail for prior art, if anyone used an infrared camera in this way prior to their filing.

  17. GBA Editor
    Allison A. Bailes III, PhD | | #17

    Obviousness and prior art
    Yes, the evidence seems to indicate that the patent *could* be overturned. The burden is on those who want it overturned to come up with the money and lawyers and mount a legal challenge that actually does get the patents rescinded. Right now, HomeSafe has all the advantages because they own the patents.

  18. gusfhb | | #18

    If there is prior art, there appears to be hope. Any magazine articles prior to 2004?

  19. Philipp Gross | | #19

    I heard this on This American
    I heard this on This American Life too and it made me extremely upset back then and yet again today. Somebody should file a lawsuit against whoever is responsible for allowing these patents. I would totally donate to that cause.

  20. Billy | | #20

    The This American Life story was one-sided and shameful. I usually enjoy that program. There is a lot of misinformation about patents and the patent system, and suddenly any blogger is an "expert" on the subject.

    The truth is there are some patents that should not have been issued, but this does not mean the patent system is broken and that it is OK for large companies to stomp on the little guy who has obtained a patent for their innovation.

    I don't know anything about the case you mention but perhaps that patent should not have been granted. In that case the patent owner will spend a lot of money and get nothing, and they may have to pay fees for the defendant. Let the system work, but don't let the massive companies crush the patent system based on a few bad examples, because then our American companies will have no tools to fight the large companies or foreign companies who steal their ideas.


  21. GBA Editor
    Allison A. Bailes III, PhD | | #21

    Response to William Geary
    Billy, patent trolls stomp on plenty of big companies, too. Go back and read what my lawyer friend said about the owner of the patent for "Press 1 for customer service..." Plenty of people in big companies and small say that the patent system is broken. Ira Glass didn't invent this problem.

  22. heidner | | #22

    Prior art
    I'm sure volumes of prior art can be found - within the US. I am most disappointed that InterNACHI settled instead of starting the rallying of forces.

    Years ago I had written some software for long time employer that involved handling dates in the YMD format. Around 2000 I saw a patent that had been approved for something we had been using for nearly ten years and sold commercially - and I wasn't the only person to do so... I had thought about working through the process to force the prior art and invalidate the patent. Another company contacted the patent office first and it was overturned.

    Even though HomeSafe may have the patent - they have to sue to enforce it... and if there is significant prior art out there... their patent would be overturned. InterNACHI other associations and existing manufacturers could have stepped up to help defend Russell; ending the silly trolling when it started.

    On the other hand, I do have this really unique idea for a slender metal object designed to be rapidly fired into natural building materials, anchoring them together and allowing more complicated structures with multiple corners, specially designed rain protection, superior daylight entry features; while ensuring the users of said device the absolute safest and most comfortable environment to sleep and dine in. I think I will call the device -- the nail....

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