How many sessions are needed to elevate the status of a nascent house to a minor house? This also means the number of sessions required to create a first enemy house.
How long is a piece of string?
Mechanically
If you are going by the House Management rules in Houses of the Landsraad then the minimum would be 9 sessions to go from a secondary domain (10 points) to a Primary domain (25 points).
The construct Domain Facility venture requires 5 resources to increase your domain by 1 point and the Claim Domain venture takes 12.
You can just about scrape out 10 or so resources from a secondary domain (more if you abuse the Treasurer loophole) so that you can get your +15 domain points and then the extra 12 resources to build it up.
Narratively
From a GM and probably player, perspective that sounds terribly dull.
I am a very narrative heavy GM. I would much rather have them set objectives in game that they can work towards. Either arranging hostile takeovers to rapidly build their domain (and thus generate the enemy) or lobbying larger Houses to sponsor them and get them that way.
Doing it that way I would target 4-5 sessions to build your House from Nascent to Minor. At that point they are stepping into a bigger universe, no longer so limited to one planet. They have the resources to travel and dragged into bigger affairs and will have built up their enemies along the way.
The big jump is Minor to Major. Nascent to Minor is much simpler in comparison.
OK, thanks for the answer.
I will add some objectives in game to target 5-6 sessions.