Exit133 is about Tacoma
Imagine Tacoma – Vertically Challenged 101
With the City Council’s decision this week to contract a property transfer and contamination clean-up of the Sauro Site at S. 14th and Pacific (with the goal to retain the Russell Company in Downtown Tacoma) and further to the recent discussions about the desire for taller buildings in the downtown (see Erik Emery Hanberg), Imagine Tacoma provides a brief analysis of the challenges of ‘going up’ within the core:
Why is there an underground tour in Seattle and not in Tacoma? Because Downtown Seattle is mainly built on silty soils and Tacoma is built on hard pan soils the consistency of rock (and thus why we bounced during the Nisqually Earthquake while Seattle swayed). For most of downtown, the resistance of going down becomes extremely difficult (and thus expensive) after 15 feet – and I’m talking dynamite difficult. Although parking regulations may be reduced downtown for new construction, the reality is that any project of considerable size will require significant parking and servicing of the building structure below grade – and thus having to deal with the hard stuff.
Tacoma has a flow of perched water coming down the hillsides. Any excavation needs to provide a system of dewatering – and the deeper you go, the dewatering becomes more of an issue.
Tacoma is built on a hill. Really. I know the City brings bicycle commute experts in from Copenhagen who tell us how to bike more, but downtown Tacoma is on an East slope and South slope (with approximately 350 feet of grade elevation from the Thea Foss to MLK). Thus, any tall structure needs to be at least 250 feet tall just to get above the hillside to the West. Why? Because otherwise you limit your view to just the North (Commencement Bay) and to the Southeast (Mount Rainier) – and this is pretty much the same view as can be found by currently standing on Yakima Avenue. The Hotel Murano is an example of this issue – all of the windows face either North or to the Southeast. So building a high-rise building only gets you a 90-120 degree view?
Tacoma has incredibly NARROW blocks (many along Pacific Avenue are less than 100 feet wide) AND incredibly WIDE alleys (40 feet when really 20 feet or less would do). This makes any incorporation of the automobile difficult within a site (and why there is a preponderance of above grade parking structures within the core).
A high rise building in Seattle, or Portland, will cost pretty much the same in Tacoma (except for land costs) BUT you cannot get the same investment rate of return in Tacoma (unless the project includes public money – which most development in Tacoma over the past 20 years has required). And since land is so much less expensive in T-town, it is base economics to go ‘out’ rather than ‘up.’
But there is a ‘sweet spot’ for getting high – that area East of Pacific and North of South 15th (including the Sauro Site). This is an area of the core that is conducive for getting down (and thus going up) as excavating is easier (lots of areas on fill instead of hard pan), the water table is lower, the blocks are wider and the access to and from the Interstate is less bLINKered. Any vertical development stills has the hill and the base economics to deal with (no small matters), but at least the physical components are manageable.
Do you want to help the folks at Exit133 pay our bills and keep up with of all things Tacoma? Do you want to see even more coverage? Exit133 has always been free to read and comment, and it will stay that way. However, over the years, readers have contributed to the bank account to help us keep up our coverage of goings-on around town. Contribute and this message disappears!Support Exit133