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Loving your attitude.

I often feel like with a lot of building (big and small) there is insufficient evaluation of site factors. For example:

Is there a hill above the site? THAT needs to be evaluated (sometimes they do, sometimes they don't).

Is the site on a traditional floodplain? If so what actions have been taken to redirect the water flow? Does the system have the capacity to move the water away?

Is the site itself earthquake proof (e.g. subject to severe liquefaction)? Just because the property is built to code, doesn't mean the land it is built on is safe.

Is the site subject to wildfire risk? Can we mitigate that?

Humans make the same mistakes again and again. We build fast and we don't consider the land's natural problems. INstead we just build and hope it happens far enough in the future for it to be someone else's problem.

Water in particular we're TERRIBLE at managing. We build property on floodplains and are then "surprised" when it floods. We place homes on downward elevations and don't redirect the water around the property (e.g. using french drains).

I did a lot of things to reduce risk. None were expensive. I watch other houses go up in the neighborhood, and they do none of them.

My most expensive mistake was not having a geothermal heading system installed when the yard was all dug up anyway. I could have had it essentially for free, and save 30% on the heating bill.

What type of system were you evaluating? I'm not sure why this isn't a common feature in homes, as I've only seen it done on more industrial scales (e.g. mid-sized condos).

I just bought two of these: http://www.bosch-climate.us/products-bosch-thermotechnology/...

I have only installed one, and I can't comment on how effective it is at reducing cooling costs as it's a new home (though I lived there for a couple of weeks before I got the heat pump units). But I can comment on the "why not".

Generally it's very expensive to install because it requires several thousand feet of underground pipe to normalize the temperature of the water going through the system. Many homes don't really have enough land to support this horizontally. You can install the loop vertically (like a drilled well), which is again, pretty expensive up front. Few take the long view.

I happen to have plenty of land and a backhoe so I just dug a ditch.

Or one could just live in a place geologically suited for human habitation, such as the northeastern United States.

Yeah, but then you'd have to live in the northeast.

Tell me more about why the place you live is better than every other place in the world...

Well, Phoenix is about as geologically stable as it gets, but we get hell on earth hot in the summer months, vs. hell froze over cold.

Watching videos of the aftermath of the floods in Maryland the other day was telling - the main street had been entirely washed away, exposing the foundations of the buildings. The modern constructions essentially had none and were hanging in mid-air over voids. The older buildings were all sat upon massive and well dressed masonry.

In short, people account only for risks they have experienced firsthand. When you don't see flash floods or earthquakes for generations, you get lax. Sadly we tend to wait until after disasters to learn, and yet we still forget.

DO you have a link with visuals? sounds fascinating.

Lots of material out there to chose from, but here's a place to start:

https://www.nbcnews.com/news/us-news/amp/maryland-vows-rebui...

It happened in Ellicott City, Maryland.

Google Elliott City flooding. That's where it happened.

Tangentially related, I have a chum who used to work for the UK's Environment Agency.

As some may have noticed, the UK seems to be suffering flooding more than it used to. Part of his job was to speak at town halls and village church halls and the like during and after flooding. He'd take a backup man with him whose job was to sit in the car outside with the engine running.

So he'd turn up at a newly built settlement named "Little Flodington" or some other such. He'd look at the unforgiving rocky hills surrounding it, and at the river running through the middle of it. He'd check the history to find that for the last thousand years, the only recorded usage of the land was grazing animals and growing crops that can handle a lot of water. No buildings more elaborate than temporary shepherd huts. He'd open up the department's flood-risk maps from the last fifty years and find he was standing in the middle of a big blue section.

He'd then field questions along the lines of "Why didn't you stop my house being flooded?" and "How are you going to stop it happening again?" with answers that were not well-received. "You bought a new house on a flood-plain. We're not going to stop it happening again."

He's since moved on up to work for a local council's environment dept. A council with less flooding.

Growing up in London, I remember reading at a young and impressionable age the sage advice to never buy property built on streets called Marsh Lane, and similar, so it's not a new problem. Geography would be a lot more interesting as a school subject if they taught this kind of stuff - although I rather fear for the results when the kids got home to explain it all to their parents.

Looks like you would have actually done ok on Marsh Lane NW7 http://www.rightmove.co.uk/house-prices/NW7/Marsh-Lane.html

Same here in Germany, people build in "big blue sections" because the nature is nice and the land is cheap, then they get flooded.

And don't forget to throw in some insurance, aka moral hazard.

Insurance ought to just price people out of areas that are too risky.

Why doesn't it?

Here, people build houses - according to media - and afterwards complain that they can't get insurance.

I live in the Outer Richmond district of San Francisco, which was built on sand dunes. Most houses in my neighborhood were built in the 1920s and 1930s, +/- a decade.

I was told by a contractor that it's extremely common for houses to have shifted considerably, sometimes by several feet. Mine certainly has, though not nearly that bad.

Most of the houses are built on concrete foundation walls that go about 3 feet into the sand. Despite being unreinforced and using water-permeable cement, they've seemed to hold up reasonably well. It's usually the whole house that shifts and racks. Yet looking from the street you wouldn't expect that because all the houses abut each other, with only a few inches or none of space in-between. (Perhaps this has mitigated the problem somewhat, though.)

Despite being built entirely on giant sand dunes, the Richmond district is only "moderately" prone to liquefaction. And there wasn't much notable damage during the 1989 earthquake, AFAIK. I think (though cannot confirm) that similar foundation techniques were used as far back as 1905 and earlier, in the Richmond, Sunset, and elsewhere, and judging by their survival and continued use of the foundation techniques I'm not particularly worried. (While widespread building in the western half of the city didn't begin in earnest until about 1910'ish, there are hundreds of buildings many decades older randomly distributed, especially closer to the beaches.)

The bigger problem is that almost all houses in the western half of the city were built with so-called soft stories as the first floor--basically a giant open space supported almost entirely by the external walls. Interestingly, AFAIK this design came before the widespread introduction of cars. These days nearly all houses use that space as a garage, but I believe they were built as unfinished first floors intended to be finished as desired--e.g. workshop, additional family rooms, in-law apartments, etc--while keeping the initial purchase price low.

The city is currently requiring many owners of soft story buildings in the Outer Richmond district to pay for seismic refitting.

Only those buildings with 5 or more units, which is only a tiny fraction of the structures. Ideally it should be every building, but it's ridiculously expensive to install moment frames, which is pretty much what every house needs given the typical layout of the houses. Each installation costs between $30k to $50k, and as well-off as you need to be to afford to purchase in San Francisco, that's still an expense few can justify even if they could afford it.

We had structural plywood sheathing installed in our garage, and the typical job is around $10k. The pre-existing sheathing was installed by [presumably] a fly-by-night contractor shortly after the 1989 earthquake. Fortunately I noticed that it wasn't installed correctly and used the wrong materials, and so it was basically useless. But given that the garage door, garage side entrance, and entryway make up greater than 80% of the front wall of our first story, that we have a big window and door on the back wall, there's not much room for sheathing (properly installed or not) to control movement along that axis. The house is now very unlikely to collapse into the street, but we're still lucky to be sandwiched between two other houses. Fortunately, our neighbor on the corner had his foundation rebuilt and a third structural wall installed. I should probably be remunerating him somehow.

...And allowing them to pass on 100% of the cost to their renters.

So, you think landlords should operate at a loss for the benefit of their tenants?

On the other hand, how fast does an empty unit depreciate in value?

So you think that capital investments (in this case property) should have zero risk, in other words guaranteed returns?

Obviously not. If the price is too high, people will not pay it.

I didn't say anything about zero risk. As the sibling comment indicates, if the cost is too high tenants will refuse to pay it by not renting the place. How long it takes the landlord to recoup the costs will depend on the local market for rentals.

Not at all. I do, however, feel there should be some incentive for him to shop around for a good price.

We call that "the profit motive"

Landlords may be the only group outside of government who is notorious for always going with the lowest bidder for jobs. A landlord who doesn't shop around for everything isn't going to be in the real estate business for very long.

The fact that they're not able to pass 100% of the cost of whatever capital improvements they feel like on to their renters is part of a massive wealth transfer from landlords to long-established tenants.

In other circumstances I'd accuse that of deterring investment and being a contributor to the terrible housing situation in the Bay Area in general, but honestly, the zoning / planning-permit situation is the first limiting factor.

Instead of "massive wealth transfer", I think you meant to write "slight dent in disgustingly fat profit margins", because - just based on aggregate metrics - most landlords are making a stone-cold killing in this market.

Indeed, let's all shed a tear for the SF landlord. I don't know how those poor folks can stay in business when property taxes are capped and median rent rises at ten times the rate of inflation!

Clearly, you have not heard of "rent control". I know people paying $1200/month for a 2BR in the heart of the City. I even met a guy who was paying $350 for a 1BR in Nob Hill, not far from Grace Cathedral.

About 72% of SF's units are under rent control. So not all landlords are making "fat profit margins".

Individual landlords don't see (real) rent increases for apartments are all subject to rent control. They only get an incremental adjustment for inflation. If a landlord owns an apartment but it is occupied by a tenant under rent control, it doesn't matter if the property is "worth" 10x as much. His rent collected hasn't gone up, and he can't sell it for 10x as much because that tenant has very strong legal protections around his use of the property at its price. In that case, 90% of the property's annual returns is being enjoyed by the tenant for as long as he stays there. (He may be able to realize a gain after the tenant moves away or dies, but he's still lost out on the decades of rent which he would have been able to get at market rates.)

Considering that any landlord buying a property will certainly be on the hook for the downside in a property if the housing market crashed, and you'll see that this isn't the greatest. (BUT THE HOUSING MARKET ONLY GOES UP AND WILL NEVER CRASH hahahahahaha yeah right).

Anyway. In general one needn't shed a tear for landlords and capitalists of their ilk for failure to make a profit: the money is its own reward. But we do need to respect the money (because that is the reward), the precise behaviors we are incentivizing, and the impact of political risk which we are inflict upon the people we might want to spend money investing in the region. For instance: making things like this risky means that risk-tolerant entities are likely to be involved (which means the rich guys, speculators and businesses that San Francisco loves, not individual homeowners). And the price of the landlord assuming any political risk will find itself baked into the price of any new rental property.

But as I was saying: it's kinda moot from a median-apartment-price perspective if nothing new gets built anyway for other reasons.

I lived in SF's Inner Sunset for several years. When the old DeYoung museum was demolished and all the landscaping scraped away, the "soil" underneath was pure sand.

I noticed the same thing at my home a few blocks away -- the city had to dig a trench in the street and after they got down a few feet, there was no soil, just beautiful beach sand. A little disconcerting with SF's earthquake history.

Aha!

"In Paris, the famous phrase Sous les pavés, la plage! ("under the cobblestones, the beach") was used by the May 1968 protesters to mean that it was possible to escape from a regimented life."

http://www.ruerude.com/2010/05/sous-les-pavés-la-plage.html

How do you plan plumbing and electricity for houses moving several feet?

If it's the earth below houses also moving, then the problems in plumbing and electricity do not appear at the house; they appear at the cross section of the moving and non-moving earth masses, and are typically the responsibility of utility provider.

For plumbing, I don't know. That's a good question I should ask a contractor the next time it comes up. But given how old these houses are perhaps the problems are sporadic. A broken pipe here or there gets fixed and people move on. And some kinds of movement might not matter, like if the back of the houses shifts down the front end might not move nearly as much.

Also, AFAICT the plumbing comes up under the foundation walls, not through. Concrete slabs on the first floor aren't original (and you can still find the occasional house with a dirt floor at the first level), so maybe there are some degrees of freedom of movement that mitigate problems.

For electricity the Richmond and Sunset districts and I believe the vast majority of the city uses overheard wires. So there's plenty of slack.

Hi neighbor, I'm at 28th and Geary!

One of the geologists told me a simple way to judge the slide risk. Look at the tree trunks. If tree trunks are leaning, or are curved, that indicates the ground under them is shifting.

Or there is a lot of wind from a prevailing direction :)

The other thing to look at is fence posts if they are old.

I've seen fields of trees that have been clearly bent by the wind, they look different than ones from shifting ground. For one thing, there tend to be more branches on the downwind side.

Yes this is true.

One other thing to look at is fence lines. If you line up a old fence line by eye and look down the line you can see quite small ground shifts. If you do use this make sure you crosscheck with other fences close by to make sure that any deviations are not just due to incompetent fencing.

no, light will do that -- trees grow toward light

A friend of mine lives opposite some farmland. He told me the story of the owner of the farmland wanting to sell it for housing. He got a geologist in, who looked at the land and explained that this land was prime for a major landslide because of hollow pockets under the surface.

The farmer thanked the geologist, paid him, and then got another geologist in. This second geologist gave him the all clear that he was paid for, and went on his way.

I should point out that my friend lives on the DOWNHILL side of this land, so when it goes...

Building a large edifice on sand? Put that starkly, I could swear that I heard a story about it once. No idea where, though. ;)

I recall a Sunday School song to that effect, with hand gestures. "Theeeeeeeeee foolish man built his house upon the sand, the foolish man built his house upon the sand..."

I really hope the SF rules for building giant buildings are similar to recent Japan ones.

What I've heard is that after the Kobe earthquake, Japanese earthquake rules have been made so good that anything built after '95 has never fallen over, even in 2011-sized earthquakes (at least until the tsunami came).

California seismic building codes are pretty solid. The state does its own earthquake research and has definitely lead the US in terms of building codes. In the US, CA's seismic exam for structural engineers is considered the most rigorous in the country. Generally, the seismic codes are roughly at Japanese levels.

However, CA's buildings are mostly older.

But this was built in 2008

Has there been a comparable earthquake yet?

Here's a list of large earthquakes in Japan: https://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan

There have been several large M7+ earthquakes in populated areas since the Hanshin (Kobe) earthquake. Tohoku was obviously the biggest. Several of the Tohoku aftershocks were over M7. This spring there was a M7 earthquake in Kumamoto, which I think is the largest earthquake in a very populated area since 2011.

Japan get several very large earthquakes every year, but they are usually in less populated areas. It's quite common to get M6+ earthquakes in populated areas, though. As the GP notes, damage is usually amazingly limited. I experienced one and was very surprised that nothing was damaged in my house.

http://www.jma.go.jp/en/quake/ is super interesting to look at because you get a real sense of just how often Japan is hit with earthquakes (several a day!).

https://www.geonet.org.nz/quakes/felt is the same for New Zealand... there's a moderate or strong quake every couple of weeks, and little ones all the time

I, for one, would rather be building on sand rather than clay. Clay is an absolutely terrible substrate for construction. Not to mention it does not drain. Hills don't become saturated with water... the water tends to flow to ze bottom of ze hill, where it will saturate things. I'd be curious to know what exactly you are draining into... drywells and clay are not friends.

- High-end residential builder here

It drains into the storm drains, and the pipes carry that off to wherever they go :-) which is the waterways. I know that because the code people had me build a grass swale to filter the runoff from the driveway before it entered the drain.

Some other homes on the hill had to be built on pilings because they were in an area which was loose dirt that had eroded away from higher up.

I'm not sure if 'clay' is the right word, I don't know much about geology, but the geologist definitely said compacted "glacial till" which he said was ideal.

Haven't had any settling problems so far despite an earthquake and lots of rain.

I passed on another lot where the geologist said the whole hill was going to slide away at some point. The seller didn't want to hear that.

Clay can be a total pain in the ass to work with, it's more stubborn than concrete to remove, but you'd be hard pressed to find a material more solid to build on than rock. What's your beef with clay?

The kind of glacial packed clay mentioned in this article is the sort of stuff even a power shovel has trouble with. It looks like light coloured slate, dry, brittle, and dense.

I'm not sure what your preference for sand is other than it's easy to work with. That stuff can shift, it bloats when wet and heaves with frost, settles like crazy under pressure. Sure, it's easy to remove, but it's so variable I have no idea how you'd get anything to stay level on top of it.

Not sure but my understanding is high clay soils expand and contract seasonally due to moisture changes.

In a location with a variable water table this could be trouble, but I'm not sure it's going to be much better in the same situation with sand.

I wonder what kind of foundation these homes are built on. Do they include a full basement?

> Sure, it's easy to remove, but it's so variable I have no idea how you'd get anything to stay level on top of it.

Living somewhere built on what is apparently some of the most variable types of clay and that experiences temperature swings of ~150F throughout the year: we don't.

Any basement more than 30 years old is cracked and heaved. Houses require constant adjustment of the teleposts to avoid large cracks forming in the house built on top of the foundation.

>I can't conceive of building a 58 story building on sand in an earthquake zone There are ~ 8 stories of concrete underground that is is built on. It would be another ~12 stories worth to get down to bedrock. Someone screwed up here but there are plenty of buildings that don't go all the way down to bedrock and are just fine. Maybe if they would have went with a lighter steel frame construction instead of concrete or if the building wasn't so tall the foundation would be fine.

I couldn't resist looking up the monty python bit :) https://www.youtube.com/watch?v=aNaXdLWt17A

fwiw: the whole dialog between the father and the guards that follows is awesome -- reminds be of requirements discussions.