You get the cost of providing the service back, he still has a house. Allowing the dwelling to burn to the ground just results in a destruction of wealth for zero gain.
That policy means that you can't afford to have a fire crew. The marginal cost associated with putting out fires is a small fraction of the cost of having a fire department.
> And if he doesn't pay, you sue him.
And you lose because contracts under duress are unenforceable.
And you lose because contracts under duress are unenforceable.
It's not so simple. Duress is where someone forces another into a bad position, eg by setting the house on fire first. A contract made under necessity (where the house is already on fire) will probably stand, unless it's for some wildly disproportional amount.
But in any case, a contract is not always required. In cases where one party knowingly accepts the beneficial services of another, they can be billed for it as if a contract existed.
Duress only implies impaired judgment of the contract signer as due to immediate fear; it doesn’t imply the other party created the situation. Any lawyer would easily argue that the fire department charged an irrationally high cost for fire fighting that the home owner wouldn’t have agreed to had they had time to fully weight the cost and benefits of fire fighting services. In the worst case, one only need say they planned to demolish the house in the near future and therefore paying to have the fire extinguished was irrational.
A contract for non-insurance, pay-for-use fire fighting would only be enforceable if signed before the fact.