Any ideas/links would be welcome
This is not a hard rule but I believe that each field should be fairly well grouped together. Just enough to keep them quiet as a group, but not close enough to make each group feel segregated. So for example, designers often like to bounce ideas off each other while they work throughout the day. QA/Support often times need to verbally regurgitate things to new employees and/or over tech support calls, managers like to verbally remind people of things.
Remove your engineers from the trajectory line of small-talk, get them away from the door, away from the coffee refueling station, etc...
Not that anybody in the office should have to deal with distractions but it's particularly dangerous when you subject your engineers to those circumstances. One thing I also liked is that in our office we seemed to have a small barricade blocking our senior engineers from the small-talk questions that the designers would often have. For example when our designers and UI/UX people would have questions about how expensive of a task it would be to resize assets/how to handle img aspect ratios, our senior devs were at the very back of the office as a last resort. This gave our junior devs/front-end guys a chance to answer any small questions before senior engineers were distracted. (which also made them feel extremely proud and gave them some respect in the office)
Just my opinion. It really depends on how many employees and what kind of atmosphere you already have/want to create. Sometimes in building a community, it's more about finding that one individual with the right personality and letting them shine. The right person can bring together your whole office if you give them the opportunity.
good luck!
edit
I also think it's extremely important to have your engineers facing AWAY from the middle of the office. Personally I think one of the most distracting things while I'm coding is seeing things move around in my peripheral vision.