i've been thinking a lot about CLT floors of late.
i've always struggled a bit with how we do it here - thin floor plates w/ CLT panels, and it hit me in a discussion w. hundegger's wolfgang piatke - the US puts CLT in floors, the EU puts CLT in walls
and it's not just that we put CLT in floors - we also do it wrong.
in the US, nearly everyone is trying to do the thinnest floor plate they can w/ CLT. they do this by adding a layer of acoustic insulation and a concrete or gypcrete topping.
this sets up a couple of issues
1. the approach is not the best from an acoustic standpoint. yes, it can meet the bare minimum of the code, but performance isn't ideal.
we're beyond point of 4plexes in single family zones as a means towards affordable housing.
that juncture was in late 70s, when city looked at legalizing missing middle affordable housing in seattle's vast single family zoned landscape. homeowners got that killed. or 90s UV plan
per zillow, median single family home value in seattle today exceeds $950k, is expected to increase substantially over the next year.
this means the land costs *alone* for a 4plex will be almost $250k.
seattle's abhorrent land policies have only exacerbated the housing crisis
if we take a very aggressive soft + hard cost (minus land) of $350/sf for a 1,000 sf unit, then we're at $600k per unit.
this is unaffordable for those under 100% AMI without a very sizeable down payment. especially if the city refuses to adjust occupancy limits
vallastaden is a new green, mixed use urban development in the swedish city of linkoping, that was developed as an urban living expo - w/ diverse housing types and ownership models
if you asked me a year ago what the perfect urban building was, i would have said something like praeger richter's 5 story + DG baugruppe-ausbauhaus in neukoelln (berlin)
24 units
15,060 sf site
floor area is 38,740 sf (FAR of 2.6)
3m ceilings - nearly 10' - unheard of in much of seattle
each unit has a south-facing balcony or terrace
the front features a playground, and bike parking
shared garden at rear
our land use is largely predicated on the notion that residents stay in the same place for years - but the reality is that there is fairly constant turnover - even for homeowners. here's wallingford, in just the last 24 months.
on just these 13 single family zoned blocks, 36 households of have moved in 36 months
there are only about 180 homes on these blocks. that's 20% of the neighborhood that has changed, in just 3 years.
change is constant. but in these zones, only wealthier people can move in