Earlier quoted context omitted.
It really wouldn't. Not any time soon. A developer being able to build a 4-unit place on top of a single family home would increase the value of that land cause now they can sell it to four times as many people. So it's gonna be that much harder for a "regular" person to buy anything in the short term.
not sure what exactly is 'short term' here, but simple example re. supply and demand and prices: 1) there is a 100 single family homes somewhere. 2) there are 300 people looking who need to live in that somewhere 3) on top of 100 single family homes now we have 400 units built .. Can it be that price of the units for sale may get reduced for competitiveness?
Let's say you live in a neighborhood of mostly single family homes. A new law is passed changing the zoning to allow higher density, and other barriers to building up are reduced or eliminated.
A few people near you sell their homes; they're bulldozed and are replaced with multi-family units. Sure, over the short term, your home value might drop because of greater supply helping to meet demand.
However, over the long term, or even medium term, two things may happen:
1. Your home value goes up because single family homes are less available, and are more desirable.
2. Your home value goes up because developers want to buy your home in order to build a multi-family dwelling there.
Meanwhile, more people are able to live nearby, more affordably, likely cutting down their work commute and increasing their quality of life. I guess the incumbent owners really are that selfish that they fight tooth and nail to prevent others from increasing their quality of life.