[mhays]

Seattle really lends itself well to twin-tower projects.

For one, we have a tight height limit. Everybody builds to the limit, so you don't get different heights in one project.

Two, we have two main block types in greater Downtown -- 2+alleyx120x240 and 2+alleyx120x360. The smaller type sometimes gets two small highrises but the larger type makes it much easier. At 120' deep (or with 110' due to a wider street) you can fit two double-loaded rows of parking. With some blocks 360' long, it's easy to do two towers with a wide separation.

You can do a parking ratio like 0.5 or 0.8 with apartments (or more for condos) so you don't have to dig that deeply to provide parking for say 600 or 800 units. Some parking can go above grade (with other uses on the perimeter) but most is below-grade. Condos tend to prefer full blocks or fewer units due to parking. This one is about 0.9 which might fit either type.

Small units do well. Seattle thrives on techies earning $70-120k instead of actual rich people, so load up on 600 sf units that rent for $2,000 or a little more.