Here in Bellingham, in-filling the city is being advocated to reduce sprawl in Whatcom County. At the same time, many anti growth advocates fear that we will get both in-filling and sprawl.
I am an advocate for density, but I realize these anti growth naysayers might have a point. In-filling and sprawl can happen simultaneously.
To curb sprawl, there would need to be strict land use laws in the county. Watershed preservation, farmland preservation and so forth.
That could reduce new housing construction in the county. Then Bellingham would need to do in-filling in order to maintain some affordability of housing in this area. Otherwise there could be a shortage of housing if population keeps growing.
Also the county could do a version of in-filling itself. By encouraging clustered housing. Pockets of density rather than sparsely scattered 1 and 5 acre lots filling up the entire area.
The towns in the county can in-fill as well.
County and city planners talk about this, but the hardest part of this task is getting average people to cooperate.
People are slowly changing and the lifestyles that go with in-filling are getting more popular. Things like "car free" living are gaining appeal.