SAN FRANCISCO | 5M Development | 470, 400, 200 & 174 FT | 40 FLOORS - Page 7

homebucket · #**121** Posted **Dec 3, 2020, 9:53 PM**

Cladding looks pretty high quality to me! I like that deep green. Reminds me of 560 Mission (JPMorgan Chase).

Pedestrian · #**122** Posted **Dec 4, 2020, 2:38 AM**

Quote:

Originally Posted by homebucket

Cladding looks pretty high quality to me! I like that deep green. Reminds me of 560 Mission (JPMorgan Chase).

Is the deep green the cladding or just a plastic dust barrier?

Jerry of San Fran · #**123** Posted **Dec 10, 2020, 11:25 PM**

PI delivery 12/10/2020

PI Delivered

Echostatic · #**124** Posted **Dec 10, 2020, 11:33 PM**

Love seeing steel construction still thriving in other cities. Austin hasn't built a steel tower in 40 years, all concrete.

Pedestrian · #**125** Posted **Dec 11, 2020, 2:15 AM**

Quote:

Originally Posted by Echostatic

Love seeing steel construction still thriving in other cities. Austin hasn't built a steel tower in 40 years, all concrete.

In San Francisco the tendency seems to be to build residential towers out of concrete and office towers out of steel. Concrete is more rigid and I once read that the thinking is that the swaying in tremors unnerve's people in their residences too much but they'll tolerate it at the office.

Some steel buildings built recently have various methods of seismic damping from base isolation to diagonal shock absorbers at upper levels. The city's 911 control center is on the former, for example and a recent large hospital uses the latter. A couple of residential towers also have large water tanks on their roofs with interior baffles that are intended to damp swaying either in high winds or tremors (the building seen in the above photo just behind the crane is one of them).

iamfishhead · #**126** Posted **Dec 11, 2020, 3:27 AM**

Quote:

Originally Posted by Pedestrian

Some steel buildings built recently have various methods of seismic damping from base isolation to diagonal shock absorbers at upper levels. The city's 911 control center is on the former, for example and a recent large hospital uses the latter. A couple of residential towers also have large water tanks on their roofs with interior baffles that are intended to damp swaying either in high winds or tremors (the building seen in the above photo just behind the crane is one of them).

Yeah, my first thought when I learned about tuned mass dampers was, "Wow, that's very clever and very cool".

craigs · #**127** Posted **Dec 11, 2020, 4:30 AM**

I worked on the 42nd floor of Spear St. Tower and the 40th floor of Four Embarcadero--both steel frame towers. Tremors are smoothed out in steel frame construction at those heights, but the sway is so extreme that it made me nauseous, and that doesn't even happen to me at sea.

BobbyMucho · #**128** Posted **Dec 11, 2020, 4:51 AM**

Quote:

Originally Posted by Pedestrian

In San Francisco the tendency seems to be to build residential towers out of concrete and office towers out of steel. Concrete is more rigid and I once read that the thinking is that the swaying in tremors unnerve's people in their residences too much but they'll tolerate it at the office.

Is the reasoning not more of a cost thing—with steel being more economical, faster, etc.

I’m curious if there’s any good math or specific rationale for residential towers compared to commercial vs just a by-project basis.

Pedestrian · #**129** Posted **Dec 11, 2020, 4:57 AM**

Quote:

Originally Posted by BobbyMucho

Is the reasoning not more of a cost thing—with steel being more economical, faster, etc.

I’m curious if there’s any good math or specific rationale for residential towers compared to commercial vs just a by-project basis.

I’m just repeating what I remember reading a long time ago. But it does seem to me that if one form had a serious cost advantage, there would be more of a preponderance of that in all types of construction.

Jerry of San Fran · #**130** Posted **Dec 11, 2020, 8:16 AM**

Steel/Concrete Buildings - as far as I can tell the Fox Plaza which I have lived in for 49 years is a steel framed building with a lot of concrete. Here is a picture taken when there was a seismic upgrade a few years ago. The work was done inside of apartment closets which caused some tenants to have to move out for weeks at a time. Lucky I did not have work done in my apartment.

One winter many years ago the building was moving so much during a storm my book cases were creaking. Earthquakes? Been through a few good shakes!

From what I have read the Fox Plaza does not have pilings that rest on bedrock.

Earthquake Retrofit_chip concrete to expose W18X beam

fimiak · #**131** Posted **Dec 11, 2020, 8:31 PM**

I would like to chime in that offices recently have wanted to maximize the open office concept, which steel favors in conjunction with glass and unfinished ceilings. Residential spaces on the other hand can be easily modeled around concrete pillars.

Jerry of San Fran · #**132** Posted **Dec 29, 2020, 12:53 AM**

12/28/2020 - My first look at the skin on the lower floors which from what I see in the artist pictures will be different from the upper floors. The empty area upper right will be a terrace.

5M - 2020_12_25

tall/awkward · #**133** Posted **Dec 29, 2020, 1:04 AM**

Is this one topped out?
I walked by today; it looks very impressive right now.

Pedestrian · #**134** Posted **Dec 29, 2020, 4:49 AM**

Quote:

Originally Posted by tall/awkward

Is this one topped out?
I walked by today; it looks very impressive right now.

Pretty darned close if not actually . . . judging by how it relates to the Intercontinental Hotel across the street now and in the renderings. In those it appeared to be just a few stories taller which it now seems to be.

Jerry of San Fran · #**135** Posted **Dec 29, 2020, 8:50 AM**

I have noticed that the top 3 stories are a different metal color. Are these floors the mechanical floors? I though this building was to be 40 stories but my count does not come to 40 stories. A telephoto view from my apartment in the Fox Plaza.

5M December 2020

tall/awkward · #**136** Posted **Dec 29, 2020, 9:27 AM**

If I'm not mistaken, this is the office portion of the 5M project, and I think you're correct that the different colored portion is a mechanical floor on top of 25 floors of office space.

The 40-floor residential tower is yet to come, and will be right next to it.

viewguysf · #**137** Posted **Dec 29, 2020, 6:34 PM**

Quote:

Originally Posted by Jerry of San Fran

I have noticed that the top 3 stories are a different metal color. Are these floors the mechanical floors?

I think the lighter weight steel is for screening to hide the mechanical penthouse and finish off the top of the tower. We saw the same thing on 555 Mission, NEMA (not well done), and many other buildings, especially Salesforce Tower. You can see structural steel for a mechanical penthouse behind the lightweight steel.

Jerry of San Fran · #**138** Posted **Dec 30, 2020, 7:10 PM**

Thanks tall/awkward and viewguysf for the input. I have been uncertain of exactly what I was seeing from my vantage point due to distance.

Jerry of San Fran · #**139** Posted **Dec 30, 2020, 7:13 PM**

I notice this morning that I can see partially what is apparently the north end of the development. See below the yellow crane. The south end of the development is seen on the right as steel frame.

5M - 2nd Building

tall/awkward · #**140** Posted **Dec 30, 2020, 9:09 PM**

That yellow crane is working on the shorter, 200-foot residential building. It's going up fast!

The 470' building would be closer to the office building...assuming it still happens...