Disposable Cities? What Christchurch taught us about Resilience

Quake strikes!  You’re safe, your building is standing.  No damage is visible, but soon you learn it has to be torn down… What?

Now think back to that minor crash in your 10-year-old car.  Only a small dent, but your insurance says it’s ‘totaled’ – repair costs exceed the car’s remaining value.  Your payout is the remaining value and you put it toward a new car (or not).

Something similar happened after the M6.3 earthquake in Christchurch, New Zealand five years ago today.  Buildings with as little as 10% damage were torn down instead of being repaired.  Downtown Christchurch was cordoned-off, parts of it for years, with no public access.  Nearly 70% of inside the blockade were demolished.  Recovery and rebuild will now take a generation.

Is this mentality of ‘disposable buildings’ acceptable for our cities?

Chch aerial

Here’s a specific example of the ‘total loss’ of Christchurch’s tallest building, the 26-story Grand Chancellor hotel.  Built with modern anti-seismic building codes, it experienced a noticeable tilt due to major damage in a segment of wall that supported several floors above the open-air drive lane.  An irregular structural layout put particular stress on that column, but all occupants stayed safe.

A formal engineering report points to causes and future-looking building code improvements.

I’m aware of a private engineering study that suggested the damage would be feasible to fix, with repair costs a fraction of the total building value at the time.   So why was it torn down?  It had become a marketing nightmare.  Customers would remember the photos for years.  They would be nervous about safety in aftershocks.  They would avoid the whiff of catastrophe at any cost.

This wasn’t an isolated example.  To the shock and dismay of the public, many Christchurch buildings with only minor damage are now demolished for similar reasons of public visibility.  The EERI post-earthquake report states it succinctly: “significant damage to critical elements was visible in a number of buildings.” (emphasis added)

Nor is the notion of disposable cities unique to Christchurch.  Throughout the US, even in a place like San Francisco where building standards are strictest, we could be in for a major after-shock at the number of buildings ‘totaled’ after the next big quake.

Granted, this isn’t quite the same ‘totaled’ as for car-insurance, but it begs the same question, and at a larger scale: Isn’t it wasteful?  In the long-run, maybe.  But modern-day developed-world construction requires a short-term mentality because of speculative financing.  What’s the right balance?

For many Christchurch buildings, the value of preserving reputation exceeded the cost difference between repair and rebuild.  Perception trumped scientific evidence: in this case, perception of safety.

Lesson: The gap between public expectation and reality means losses can spiral far beyond damage.  This is important not just for the construction industry but also policy and finance.  Closing the gap requires greater resilience – in our infrastructure, but also in our social and economic structures, as well as our individual decisions.

A call to ‘greater resilience’ doesn’t mean always ‘preparing for the worst.’  Building codes, for example, should continue their main goal to protect life-safety, and not necessarily expand to preserve property values.  But developers need ‘eyes wide open,’ first to know about, and then deliberately weigh the consequences of a disposable building, a disposable city.

At the civic level, we need to quantify and communicate future consequences of decisions otherwise pressured by a short-term outlook.  Standardized metrics of sustainability and resilience are an important first step.

As individuals, increasing resilience means giving ourselves options in how we respond.  For some of us, this might mean getting to know our neighbors so we can share resources if needed.  For others, it might mean greater savings or financial products that make it easier to pick up and start again.

Over to you:

Do you expect our cities to be ‘disposable’?  Is that OK?

What steps would build resilience at civic and individual levels?