Add the following rule called “House Market” to the ruleset:

There is a publicly tracked list of Houses, each with a publicly tracked Seller, which defaults to None and may be the name of any one Realtor. If the Seller of a House becomes idle, then all houses they were Selling have their Seller set to None. Each House has a publicly tracked name which may be used to refer to that house, which may either be in the format of “N Dade Street” or in the format of “M Arveg Lane”, and defaults to one of those two formats, where N and M are arbitrary numbers between 1 and 100 not already used for that respective variable.

Each of the terms in the following list is an Attribute that each House also has.  Every Attribute is publicly tracked for each House. Attributes may be any number ranging from 1 to 10, and default to 5.
*Condition
*Size
*Appeal

Each House also has a publicly tracked list of Traps, which defaults to empty.

Let X be the number of Realtors plus two. If at any point there are less than X Houses listed, then any player may add another House to the list of Houses, with a name using one of the name formats described above of that player’s choice and rolling a DICE10 for each Attribute of the new House and setting that Attribute as the result.