Not sure how popular this opinion is on here but I generally think we should be disincentivizing rental properties as long as we have a shortage in the housing market. Otherwise land and rental prices just rise because it makes more sense to rent than to sell. My naïve solution is something like "You pay 60% property tax on your primary residence and add 40% for each additional one". Then if you wanted to own and rent 8 houses you could but you'd be paying 300% property tax on the 8th house, which would change the incentives so it makes more sense to sell than to buy up properties and plan to rent them out