Hey David, re: your comment about radio waves. Some researchers have demonstrated that acoustic waves can suppress fires (via rapid displacement of oxygen), but to my knowledge these have all been small-scale “laboratory fires”. DoD and FAA have shown interest in further developing technology to quickly suppress incipient stage aircraft/spacecraft fires, but some have proposed using it on vegetation fires
(see here for an article discussing one implementation). I am skeptical for many reasons, but it’s interesting nonetheless.
There are a lot of complexities in wildland fire that do not exist in small scale compartment fires, mainly that the scale of the problem is orders of magnitude greater and oxygen supply is unlimited. As Birken_Vogt mentioned, as the fire grows beyond a very small size, most extinguishment technologies become impractical.
Regarding your specific structure protection idea, I agree with the numerous technical challenges that many have mentioned here. However, I think many appreciate your motivation. If you can figure out how to make simple, affordable, reliable structure protection and convince homeowners to adopt it (along with following Firewise principles), a lot of structure losses could be prevented. This is a hard problem, even when you have a successful product (for example, residential fire sprinkler requirements for new construction homes have saved many lives, but widespread adoption throughout the US is still a distant goal)