I've made several contacts in the Netherlands with operators who have/are putting in their own open-access fiber networks and I contacted them with the question about network topology over the weekend.
I explained that I was originally interested in having a simple "active star" topology with the fiber aggregation point in the middle of the residence and an individual conduit to each home going out from the center like the arms of an octopus. Vincent raised some concern that this could mean I'd need much bigger trenches right next to the aggregation point because I'd have to put a large number of conduit together.
I wrote to the FTTH experts in the Netherlands and asked for ideas, explaining my concerns and looking for their suggestions. They responded quickly and said that running individual conduit to each house from the center was probably the best way to proceed - given our particular geographic and cost factors. The maximum number of conduit I'd be putting in any trench would likely be 8 (with the exception of the two apartment buildings). There I could probably run a larger conduit which would support a thicker cable of fibers.
I'll get back to Vincent and ask for his advice from here.