Okay - so shall I advance to the end of Spring/Summer 1230, leaving Autumn 1228 blank for now? Are you planning to run the tribunal and 1230 story simultaneously or in parallel? (I'd probably prefer in parallel if you're expecting the tribunal story to be relatively inconsequential, so we can get time moving, but it depends on how quick you expect it to be and whether there is likely to be anything in it which would be likely to affect future development in it).

I completely forgot about that one. I can work the details in the next few days, but yes, you're right that it'll be difficult to do before Autumn 1228. OTOH, if both Gregorius and Viola are at tribunal, Viola can get them both back quickly with Arcadian Travel.
I suspect by the time he's got to and participated in the tribunal, it'll be well past 10 days?

Which new buildings? I'm not questioning, just admitting my poor memory.
Unfortunately some of the old posts detailing their construction appear to have gone missing - there's a link to them, but it doesn't go anywhere useful. However, there was a blacksmith's workshop, carpenter's workshop and infirmary built as of Spring 1228. Gregorius described them to Stephan as follows:
"Those buildings over there" - he points to a pair of buildings situation in the northern part of the square, but doesn't walk over to them - "are a couple of craftsmens workshops. That one" - he points to another set a little distance on its own - "is the infirmary."
I think the plan was to next create a barracks and a mason's workshop - I think those can both be done by the end of 1228, so I might alter the "selling the stone" plan to not start until after they're built, as a barracks in particular would be useful (the existing buildings are rather cramped), and the mason's workshop will help us get to proper export levels. Of those, the mason's workshop will be down at the quarry, and the barracks in the main clearing with some space outside it for a training yard.
Edit: I think this is what I was looking for: Covenant Development - #254 by Salutor

Autocrat (Mason)
Spring 1226: Autocrat begins quarrying operations. Initial work doesn't produce any useful stone (getting to quality rock).
Summer 1226: Quarrying production under way.
Autumn 1226: Directs team to construct forge for blacksmith.
Winter 1227: Quarrying production under way.
Spring 1227: Quarrying production under way.
Summer 1227: Quarrying production under way.
Autumn 1227: Directs team to construct carpenter's workshop.Carpenter
Spring 1226: Carpenter directs initial tree felling. Wood mostly used up by Gregorius.
Summer 1226: Carpenter directs tree-felling operations.
Autumn 1226: Carpenter assists in building forge for blacksmith.
Winter 1227: Carpenter directs tree-felling operations.
Spring 1227: Carpenter directs tree-felling operations.
Summer 1227: Carpenter directs tree-felling operations.
Autumn 1227: First lot of seasoned timber ready. Assists in building carpenter's workshop.At the end of the period, we have 3 lots of timber and stone ready to build things with - the project is just about to take off.
Plans for future buildings:
- A infirmary for Petrus. The storeroom he was using can then be changed into a guest lab, and the patients can get out of the cave with the negative living conditions modifier.
- A proper workshop for the mason, probably down near the quarry.
- A barracks
- A stables? Damianos is pushing for one, although there isn't much actual need yet.
- A sanctum for Gregorius.
- Assorted other sancta for visiting magi.
- A dedicated library.
Which says 3 lots of building materials after the carpenter's and blacksmith's workshops are done, so that being the infirmary plus a future barracks and mason's workshop seems consistent.