Contact
Corrections
The most useful thing you can send. Prices move, codes vary by jurisdiction, and a figure that is right nationally can be wrong where you build. Tell me which calculator and what the number should be, and a source if you have one. Every assumption is published on the methodology page so you can point at the exact one.
A calculator you need that is not here
Say what you are trying to work out and how you would normally do it by hand. Requests that come with a real job attached are the ones that get built.
Privacy requests
Access, deletion or any question about data goes to the same address. See the privacy page for what is collected — which is very little, and never the dimensions you type.
Response time
This is a one-person project, so replies take a few days. Corrections get acted on faster than they get replied to.