Unless they told you that they would charge you for the estimate or that they had to draw up plans and send them to the inspector, you would not have to pay there was no enforceable contract or agreement for you to pay for the plans, estimate, etc. because there was no "meeting of the minds," or agreement between you as to what was to be done and charged. An enforceable contract or agreement requires that the two parties be basically on the same page. When they're not, and one party unilaterally on its own without authorization incurs expenses or does work without the authorization or consent of the other party, the first party has to absorb its own costs. That's the law. Practically, you may need to be comfortable dealing with a lawsuit and appearing in court if you're going to refuse to pay, because it is almost impossible to stop someone from filing a lawsuit if they think you owe them money therefore, that business may choose to try and sue you for the money, even though, based on what you write, they do not appear to have grounds to force you to pay.