Buying, Building, and Expanding Property

A Bastion is a location that belongs to a player character: a home, a stronghold, and a place of power that the character develops over the course of a campaign. A Bastion offers a character temporary refuge from the dangerous world of adventuring, and it provides opportunities for a character to craft magic items, conduct research, harvest poisons, build ships, and carry out a range of other activities.
Regardless of whether a player wants to develop a Bastion, every player character can acquire, build, and expand a home or base. This can be in conjunction with the Bastion rules or in addition to their Bastion. Using the terms from the Bastion Rules, this real estate would be considered "Basic Facilities".

Buying Real Estate

The GM has a basic cost for real estate in a community or city district, such as "in this district a simple home costs 800 gp, and a grand home costs 4,500 gp" The player chooses what he's willing to spend and, let's say, buys the simple home for 800 gp. That might be enough detail for some players.
If a player wants to add more detail to the home, they player can look at the costs for the individual rooms and build his home up to 800 gp. Let's say a kitchen for 200, common room for 300 gp, and a bedroom for 300 gp. Some locations or neighborhoods may allow a discount or premium - everything is 20% cheaper in the Slum Quarter, while the Garden Quarter adds an additional 10%. The GM ALWAYS appreciates a good map, or even a sketch of the place. Use the Rooms table for approximate sizes of the individual rooms.
Some of the "Rooms" on the table below are outside spaces. These house rules assume that the land is part of the purchase of the building, and doesn't focus on acquiring "land rights" for the sake on simplicity.

Using the Rooms Table to Buy, Build or Expand

The Rooms Table below gives players and the GM the cost and size of individual room "components" of a building. A player looking to build or expand a structure would use the table below and pick the components they want, then add up the total cost of the building. As above, some communities and districts will cost less or more.
In most cases, the player will draw up a map of the building and then use the Room table to match the map and add up the cost of the building. In these cases, if the player wants a room significantly larger than the listed number of spaces (5' squares), they may need to purchase multiple rooms of that type.
The other way to use the Rooms table is if the GM or the player has a pre-drawn map, let's say of an old observatory the players adventures took them through. The GM or player would use the pre-existing map and room table to determine the cost of the building.
To expand a structure, the player decides on what rooms they want to add to the building, and pays for those rooms. Adding them to the map they have created (if any) of the building. This GM likes maps and strongly prefers them, but the maps aren't absolutely necessary.

Adventuring, the Great Unknown

All of the information above, including costs and values, are subject to change based on the players' adventures. The observatory may be worth thousands of gold, but it was inhabited by a necromancer, and now the town wants it off their hands and is willing to sell the deed for 500 gp.
The players completed an adventure and saved the town, and they are gifted the old abandoned manor just outside town. The players gain a patron who wants to keep them close buy, so sets them up in an outbuilding on their estate, or purchases a building for the party to use.

What About Bastions?

The Bastion rules are pretty slim as to how a player, or party, first acquires their bastion. It is probably assumed to come from an adventure the party undertook, or as some sort of gift. Similar to the ideas in the last section. The players could purchase a building together or each purchase separate buildings.
Bastions are supposed to start with two "Basic Facilities", one "cramped" with a maximum of 4 5' squares and one "roomy" up to 16 5' squares. The Rooms Table greatly expands what those "Basic Facilities" are and how many squares each one occupies. There are Bastion rules for adding or expanding those basic facilities, those rules would be replaced with these house rules, and the players would use the Rooms table to add space or "basic" rooms to a Bastion.
On reaching 5th level, or being 5th level if the building was acquired after that, a player can add two "Special Facilities" to their building and it becomes their Bastion. If multiple players share a Bastion, each adds two special facilities. If there is already a pre-drawn map, the players decide whether to co-opt existing spaces or to expand (and maybe redraw) the map. They player(s) then add more special facilities as they gain in level using the Bastion Rules.
If a player owns multiple buildings, they should choose one to be their bastion, and the other buildings are just normal buildings. A place to hang your hat, but not your sanctum. At this time, I'm not sure if we should split Bastion "Special Facilities" over multiple properties, my gut says no.

Rooms Table

• Room (Size - 5' squares, Cost)

• Ballroom (40-60, 760 gp)

• Bath (3-6, 130 gp)

• Bedroom (4-8, 300 gp)

• Classroom (5-20, 250 gp)

• Common Room (10-30, 300 gp)

• Courtyard (20-40, 180 gp)

• Dining Room (6-10, 400 gp)

• Dock (10-30, 320 gp)

• Guard Post (6-10, 320 gp)

• Kitchen (4-8, 200 gp)

• Laundry (2-6, 120 gp)

• Lavatory (1-4, 120 gp)

• Nursery (8-16, 250 gp)

• Office (4-8, 400 gp)

• Sauna (2-5, 120 gp)

• Shack (4-8, 100 gp)

• Sitting Room (6-10, 480 gp)

• Storage (4-8, 120 gp)