I see. In Australia, your house to your office, it's the same amount determined by square footage. That's why investors build tall buildings to minimize land tax. The only difference is location, more opulent or more urban areas need to pay higher land tax. Kenya however, compared to Australia doesn't have a lot of land so land tax should be higher like Korea.
The type of housing matters. It would be unwise to give low-incomes families a house- more appropriate to build a public apartment block and make it affordable so everyone can pay a portion of that land tax. These are highly specialized, sciency economics calculations determined by lots of statistical factors- wage, location, employment rates, potential income etc.
I think there needs to be a balance of private and public. For instance a private park is usually better maintained than a public park. Because the govt still needs to find funds to maintain public sites. Sometimes half private, half public is a balanced alternative to plug those deficits. Like half public hospital for everyone, half private for those with medical insurance.
Just seizing land can cause a litany of lawsuits, the govt can't get away with that without paying sufficient compensation, not to mention costs to hire lawyers dragging up to 20 years for a settlement.
I think the best way is to implement land tax and let the owners decide. If they can afford to pay land tax like $10 billion dollars in 5 years then so be it. Highly unlikely though. The govt should focus on prime land locations where it urgently needs attention. Like building a public hospital in Busia because it has the highest HIV rate. Building an elephant conservation center on a portion of Delamare's land because elephants are at risk etc. etc.
Resettle low-income families or those unemployed in community based public housing/public employment projects. I've seen these in Lake Magadi for private housing projects, they have soda factories and workers housed in apartment blocks. More of that action happening at the national level. Offer public housing to those working on public projects. Designate a block of apartments for those working on conservation projects, construction projects, trade projects, keep Kenya clean projects etc. these things first and foremost need land.