The real problem is that you can't legislate envy and greed. The emotional attachment a family has to their house as home, is what creates the good will value of the estate being maintained as a house in a community of households. However, the misrepresentation that a condo unit has the same equitable value, on par, as a home is so widespread that people, first time buyers for instance, don't realize they don't have the same proportional "real estate" value at all.
Living in a hive of units require's more social stability than does living in freehold property's like houses, they may both be housing units but they are worlds apart in social and economic value. This was all reflected in mill rate assessment now long gone.
Bring back BENO designations on "Land Titles" and you will soon have a wealth of data points on the influences which drive commercialization of primary dwelling units. You can collect proper taxes from private rentals by setting the standards to reflect commercial ones.