Upscale communities in the region have seen a lot of new construction and major remodeling projects. 3,500+ SF new houses are not uncommon. Mercer Island, though, is one city that’s trying to limit the trend of giant mansions so that the community can retain the private, treed environment that it’s known for.
https://www.seattletimes.com/business/real-estate/mercer-island-land-of-the-luxury-home-cracks-down-on-building-mansions/
