I think that both btresist and I are using “demand” in the Econ 101 sense of the word - to describe the demand curve of all potential consumers of the good in question. IOW, for any given price, there’s a certain amount of the good (in this case, housing) that the universe of potential consumers will demand.
An increase in supply will lower prices and increase the quantity demanded - which would represent a shift along the demand curve. The demand curve can be static, but the quantity demanded is not. The California coast is lovely, but it has been thus for a very long time - that’s not really the type of exogenous change that would move the demand curve. Increasing (or decreasing) the supply of units will move you along that same demand curve.