Hello Klaus,
Thanks for your question concerning the change of the header height in the Resolve theme. If you are going to add content to the template or change the core structure, then you will need to make changes to the thf]
To add HTML or PHP content to the theme header you would need to edit the header template. The BoldGrid documentation covers the topic of editing the header template in depth. It contains all the information on making the changes within the theme.
If you have any further questions, please let us know.
Kindest regards,
Arnel C.