Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Opinions on new piping scheme
So after a lot of back and forth, I've sketched out a diagram of the piping for a proposed hot water heat system for my (older) home. Pic below. Three zones based on common heat loss rates, taking into consideration some of the physical limitations of the house. These would be new rads, with TRVs but also isolation valves to do a bit of balancing. These are all direct return; the only zone that could be (somewhat) easily piped home run would be zone one. Just the main floor rads are shown; zone 1 is above a heated basement, zone 2 above an unheated garage, zone 3 is partly above both. Just looking for some initial feedback. Thanks.