The most important thing to remember, is that the whole of Westland belongs to Lord Rignal, unless he sells it or gives it away. You can't just settle on a piece of land and claim it as your own, you need permission before you can do that.
Renting: Anyone, no matter what their status, can rent property, from whoever controls it. If you rent a business space - Rents and taxes cost 50% of the income generated (using the Alternate Professions Rules).
Leasing: Any recognised Resident Journeyman or Sergeant (or people of a higher social status) may lease property, this gives a limited title to the land and any building on it. The lease is permanent and heritable - however, there is a purchase price, and a regular, annual, fee/rent associated with the leased property. It might be some undeveloped land, a business or a residential property. However, there are clauses in the lease that allows Lord Rignal to cancel the lease. Most deal with things like abandonment, failing to pay rent, criminal activities, treason and such-like. However, there is also a no-fault clause that allows Lord Rignal to reclaim land, in return for compensation and/or resettlement. While that is uncomfortable for the lessee, the compensation is generally considered as fair, if not slightly generous. New leases must be approved by the administration, and if a lease is to be sold the purchaser must be approved by administration.
Leasing a property cost between 50 and 150% of the 'build' price, depending on the condition and location. The better the location, the more expensive the lease. Properties in poor repair, will cost less than properties in 'reasonable' repair. Rents and taxes cost 25% of the income generated (using the Alternate Professions Rules)
Leasing undeveloped land is a can of worms - Land Packages are always fairly small, rarely more than one hundred 5ft squares and the location is key. Costs can be as little as 50gp, or up to thousands of gold. Then you have development costs. Rents and fees, depend on what you build / develop there - but it is likely to be 50% of the totals income generated. Leasing, purely to build a home, tends to generate rents and taxes of 10% of the build cost each year.
Owned: Citizens, and people of higher social status, can buy land and or property outright. Prices are high, and must be approved by Lord Rignal. In most cases, he takes the advice of his administration (Governor, Chief Steward etc). This Permission generally relates to small parcel of land consisting of a single business premises, a home or a patch of wilderness (via the Venture/Development scheme). A successful Individual, Development Company (or individual members) may apply for further land grants - however, each land grant MUST be successful before the next one is granted. There are clauses that allow the ownership to be cancelled in the case of abandonment, serious criminal activities or treason.
Buying a property is expensive, often costing 3 to 10 times the leasing cost - depending on location, desirability, financial benefits etc. However, the actual price depends on a number of things - whether the Governor/Lord approves of your proposal, whether they see a benefit from it - either financial or adding to state development, even whether they like you. In some powerful cases, normally under the Development Plans, land is sold for 1cp - but still subject to standard ownership rules. What ever you build on your property, generates the full income calculated using the Alternate Professions Rules.
Development Settlements, are places where where an individual or an organisation owns most of the property in the settlement. In this case, the Owner is often granted the right to appoint the Mayor, charge local taxes, and given wider responsibilities. Proving successful in establishing, developing and managing a truly sustainable settlement may lead to the award of a Knight Dominus - and a land grant, that gives permanent rights over the land /estates in the settlement. The 'owner' still gets to appooint the 'Mayor', although the state will appoint a deputy-Governor (often leader of a small military force) to assist in management, defence and tax collecting - and check that things are done properly.
Granted: Lord Rignal has the right to grant land, in perpetuity, should he choose to. This is generally associated with the award of Knight/Dominus status - but land could be granted to anyone. There is a reclaim clause for Treason, but that is the only possible reason to recall the grant. In most cases, the land grant is quite small, but comes with businesses that can be rented out, to give the knight an income.