Contact
One address, read by a person. There is no form, because a form would need a database and this site does not have one.
Corrections are answered first
If a figure here disagrees with a published value you trust, the address of the page is enough to start with. The method page names every station, every period and every approximation, and settles most disagreements on its own.
What cannot be answered
Whether a particular building should have a particular boiler or heat pump. These pages compute a simplified EN 12831 estimate from a city's climate; they know nothing about your walls, your windows or your ventilation. Sizing a real system is work for a heating engineer who has seen the building.