Live in a suburban neighborhood and my neighbor's small shop burnt to the ground Monday and the initial investigation by FD cites wiring and a family member from their household admitted to me that it was DIY wiring.  Burnt 1/4 of my back yard, halfway destroyed our small 4x6 shed and 1/4-1/2 its contents(the rest likely damaged due to smoke/heat/water), and the heat from the shop fire melted most of the siding off the back/side of my house and broke a window.  Still waiting on our roofer to come out to determine if any heat damaged my 2 year old roof.  The day after the fire I put up tarps due to weather forecast showing storms throughout the week, so I could protect my home from water damage.

Their insurance adjuster finally shows up today, claims he's just there for measurements and not the adjuster I'll be working with, and took down my info.  He explained to me that Missouri is not a "pay to replace" or "pay to match" state and kept mentioning "liability".  Some points he explained;

• They will only pay depreciated/repair costs.  This means they might give me 5k to replace the siding/insulation/etc on my house, even if the cheapest estimate I get from a contractor is 15k.  He all but guaranteed this was going to happen.
• They will only pay the depreciated value of my shed based on condition/age, not the actual cost to replace it...so for example, they'll give me 500 bucks, but it's going to cost me 2000 to actually buy that same size shed to replace the one that got destroyed.
• They will only pay to fix the siding on the back and side of the house, because they are not obligated by state law to replace it all so it all matches.  This means I'll have mismatched new siding on two sides of the house, the others will still have my 23 year old siding.
• If I want coverage to replace all my siding, replace the shed, etc then I need to file a claim with my insurance company who may or may not be able to collect that additional money from the neighbor's insurance.
• When asked about this taking so long, and all the potential water damage my home is or may suffer from the incoming storms, he said "I really can't say much else because we still haven't conluded that we or your neighbor are liable and that there is a claim here."

Is all that actually true?  Am I really at risk of having to file my own claim with my insurance, pay out of pocket on my deductible, and potentially have my premiums increased because of damage caused by a neighbor's fire?  Am I actually on the hook to try finding a contactor, one that isn't booked months in advance already which is virtually impossible right now, and pay out of pocket to have them install better temporary protection on my exterior walls to stop water damage while I wait for all this shit to finalize?

This may not be the way it is here but I think I'd be looking for your neighbors insurance to cover it. If they say no,tell them fine,I'll be suing your client for damages. Your neighbor should be liable.
 Just my 2 cents

They'll cover it because it's clear the fire came from the neighbor's property, but covering only to a very minimal extent since homeowner's liability insurance works a bit differently than say, auto insurance.  Plus MO apparently doesn't have some laws that other states have that protect/benefit me in situations like this.  So whether or not they cover the damage/repairs, I'm still going to need my insurance compmany to step in.  This shit makes about as much sense as our tax system, and I'm sure thats intentional.

My insurance agent had me file a claim with them.  Adjuster already assigned to case, should be here tomorrow or Monday depending on the backlog.  My agent also set up appts to get a water/fire damage remediation company out here today to seal the exterior walls to prevent water damage from rain, and then come back first thing tomorrow morning to do a full inspection/walkthrough to identify all fire/smoke/water/heat damage and present an estimate to fix/replace everything.

Then, through something called segmentation(?), apparently my insurance company is going to send the bills for all this to the neighbor's insurance company.  At this point I imagine that other company could deny or fight it and turn it in to some big mess.  Not really sure what to expect at this point, and still not sure what I'm going to be paying out of pocket yet.  Keep forgetting to ask questions because I'm juggling these phone calls and trying to work at the same time, getting caught up after having no power for half a day and no internet for 2+ days...I work from my home office which is hard with no internet.

Hopefully your insurance company will give them hell.

Take your own pictures and buy a digital voice recorder at the store.

Record any conversation that other insurance company or your neighbor has with you. ASSUME they are doing the same.

Dont let the other company or neighbor bait you into saying and agreeing to anything.

I have photos during and after the fire, all the damage to my property/house, and after-photos of when I tarped the exterior walls of the house to prevent water damage from the storms this week.  Also kept the receipt for the tarps, staple gun, and even the two boxes of staples.

Phone has a voice recorder option that I have used before, and this is a one-party recording state, so I'll keep that in mind.

I know better on accepting or agreeing to any terms from them.  Every step of this is being presented to my agent for review, and now I have my own claim with my own insurance so I now have my own adjuster involved, and I have a company on the way to seal those exposed exterior walls plus do a full inspection/survey of the damage/loss.  My ins agent is the ultimate badass.  He's been the family insurance agent for 10+ years, fellow car guy, and is a big reason why I've stayed with State Farm for so long.

I'm deeply involved in auto insurance but not homeowners so I really don't know about the specifics.

Though your last bullet point of
"I really can't say much else because we still haven't conluded that we or your neighbor are liable and that there is a claim here."

That is standard talking points all insurance companies say while they investigate the claim. If all is as you say it is there's nothing to worry about on that line.

I figured it was just standard protocol, so I didn't think too much of it.  Was more concerned about the whole "we're giving you a small fraction of what it's actually going to cost to repair the damage our client caused to your home," but my agent is assuring me that other insurance company is either paying up front, paying through that segmentation(?), or both.  However that shakes out I'm damn sure being made whole on this.

Yeah that sounds like a shitty ordeal all the way around. I'm surprised this is the first I've heard of something like that happening.

I went through a claim last August for the roof and some siding due to hail and wind damage. I have State Farm. Everything went smoothly for me.

What you were told about depreciated value is only partially true. The initial check WILL be for the depreciated value, no if's and's or but's about it. BUT you will get another check to cover the difference between the depreciated value and the replacement cost (minus your deductible) after and only after all repair/replacement work has been completed. Or at least that is how it worked for me with State Farm.

I had another claim 6 years ago when the neighbors purposely burnt their house down and there was heat/smoke damage to my house. Their insurance paid for everything to be fixed/cleaned.

Others are 100% correct that your insurance company should go after the other guy. His insurance should pay for any and all damages to your property.

The word you are looking for is subrogation.

Neighbor's insurance told me they're not paying me anything unless it's proven that the fire was caused by neighbor's negligence.

8 days and counting waiting for FD to finish the report.  A hired fire investigator(neighbor's insurance) and both insurance companies are waiting on that.

Claim is proceeding with my insurance, and they already cut me an initial check this morning.  I'm also going to be out just over $2100 on my deductible for this.  If they can't get the neighbor's insurance to pay through that subrogation process, then I'm out that money and my premium will go up.

Still waiting on two different estimates to have the whole back of the house and one side redone with new  backing panels and vinyl siding.  My insurance confirmed this morning they're not doing the whole house(not bound to by state law to match siding), so I'll have half new siding and half 23 year old faded siding.  Two different inspectors confirmed the soffit, fascia, gutters, and my 2 year old roof are fine and no smoke/heat damage inside the house.  Tonight we have to empty our shed and inventory everything, then anything damaged needs to be documented and submitted to insurance company so they can write a check for that.

Still trying to wrap my head around the fact it's possible, and likely, that I am paying a single penny for this shit, like it's my fault my house was in the path of their fire.