Christchurch Update…the demolition list

By Brigid Gallagher 04/04/2011 10

On Friday April 1, a list was released that announced the fate of 68 heritage buildings, amongst others.   Designated for demolition, partial demolition or to make safe, the names of recognisable buildings are visible. 

Of the 68,

43 are to be demolished

9 are to be made safe

16 are to be partially demolished

But what does this mean?

After a couple of weeks of what appeared to be careful reporting by the media, using the word deconstruction, we seem to be back to the use of demolition.

Deconstruction engenders the idea of careful and deliberate taking apart of buildings. 

Whilst this may be a 2-fold exercise, firstly dealing with the unstable collapse material, and later the still in situ upright material; in keeping with international best practise common to archaeological works there would be conservation plans and appropriate recording, sampling and labelling.  In other words, good scientific strategies would be in place with systematic methodologies and the generation of results for interpretation and dissemination. 

 I hope after the moratorium, and period of breathing, demolition at its most basic meaning has not begun.

 I hope that, within reasonable limits, we are not losing our history.  And worse, we are losing it because the funds are not there. 

What price should we put on our heritage legacy?

10 Responses to “Christchurch Update…the demolition list”

  • Unfortunately, sometimes we must accept the inevitable, and consign some buildings to the history books. The price of heritage must be weighed against the price of safety and of progress. Napier is a case in point; after 1931, it gained many, new art-deco buildings, which it is now known for. Christchurch can become a modern, efficient, architectural, safe city.

    • I absolutely agree with some of what you say ShadowMind. Sometimes in disasters such as this we do have to consign buildings and heritage to the history books. What I hoped to advocate was that if we are going to loose them, then honour them by recording them properly. Lets not have heritage pushed down because of bureaucracy, uncertainty, chaos or funding because best practise guidelines and international precedents are not observed. There are experts in built heritage and archaeology in NZ who would gladly go to Christchurch as a ‘rescue’ team to record and monitor ‘deconstruction’ of the buildings. If the engineers and the architects say they have to go, then fine…but lets not loose the information the buildings have to offer about our past.

      Regarding your comment about heritage to be weighed against the price of safety and progress. The collapse of heritage buildings is a fraction of the problem compared with the more modern buildings. The reality is that buildings that have met the buildings regulations and deemed ‘safe’ have collapsed. Who is to say that that is not going to happen in the future. Following the big San Francisco earthquake building regulations were actually lowered so that the city could afford to rebuild. That is not safety or progress.

      Keeping discussion open regarding progress and what style it should take, allows for accountability and transparency. It insures us for the future. It should remove leaky building syndrome from the equation! No body is absolutely correct, not every body is going to be pleased with the outcome, but to infer that retaining heritage is not progress seems very short sighted and biased.

      Christchurch trades on its heritage. It is at the forefront of any advert or image. To ‘demolish’ could be seen as remiss. Look at Berlin, a wonderfully modern city, they have used some of their bombed heritage buildings to great effect; to keep the secure elements, and then build in a very modern style on top. Equally Warsaw has the most beautiful town square. But it is not original even though it looks it. Demolished by bombing in WWII it has been rebuilt in the same way, and people flock there because of its beauty. There will be more.

      I am not advocating ‘save the heritage’ fullstop. I am just asking people to think about the loss to this nation because of a lack of foresight and courage…and not to destroy something they will regret in years to come. If it is to go, lets make sure we can create a legacy in the future of its existence; whether it be through laser scanning and 3-D reconstruction or physical reconstruction at another location.

      As for Napier. Luckily for it, many of New Zealand’s young innovative architects at the time were sent in, at the crest of a new style; art deco. The result was fantastic. But, and I am sorry to sound cynical here, they also built in a time when craftsman ship was still high, quality materials used, and structures built to last…a last vestige of the Victorian period. What is the life expectancy of todays buildings? Where is the variety in modern urban New Zealand?

      So yes, I agree, Christchurch can be modern, efficient and architectural, but without the loss of it heritage integrity. Safe? I am not sure of.

      Apologies for not replying sooner, your comment was not displayed on the main blog site.

  • Sad as it is to see these historical buildings demolished, I hope that there will be salvage archaeology to see what underlies them?

    • Hi Coli, I absolutely agree with you. In line with requirements in the development and planning process prior to any rebuild this is likely to occur. If there is a situation where there will be no future development on a particular site, if funds, grants or the will, are available it would be really beneficial to the archaeological record of New Zealand to excavate and examine the sub surface remains. Particularly if there is a question regarding the future stability of that site. At the investigative level I would also be really interested to see what the shaking and rolling of the earth has done to any archaeological remains from the earliest occupation periods of Christchurch, and the effect of the liquification on remains. Is liquification literally squeezing the archaeological data on to the streets??? Even a series of small test pitting would reveal alot I am sure.

  • Hi Brigid.

    Hope to stay in touch with you about archaeogeophysics, but I wanted to comment about your comment that The collapse of heritage buildings is a fraction of the problem compared with the more modern buildings. The reality is that buildings that have met the buildings regulations and deemed ‘safe’ have collapsed.

    I want to note that, until the recent Japanese earthquake, the 22 February event recorded the greatest ground acceleration ever recorded in any urban area. Not in NZ, not in the Pacific region, but in the world. We reached 2.2 g at some recording stations. Even if we had built to withstand the previous maximum g values, those were exceeded. I suggest that instead of asking Why did the PGC and CTV buildings collapse? we should be asking Why did the other buildings _not_ collapse?.

    • Yep, good turn around David. And with that change in perspective, given the damage to many heritage buildings, I not am not sure that they would be valid point from which to investigate why other buildings did not collapse. But I like your thinking.

      Regarding the 2.2 g force, do the recording stations also record the type of movement in the ground, and has anybody looked at what changes have occured to the physical morphology and composition of the upper most levels of the earth crust?

      As for geophysics, it would be interesting to compare the results of say a GPR survey of the subsurface archaeological remains on a property in the CC area pre earthquake, and repeat in now. If such data did exist, I imagine it would be best measured outside the heavily developed CBD area, but could reveal interesting info re lift, subsidence and fragmentation. This would then have a direct relevance to the planning process and archaeological monitoring of earth works.

  • Brigid,

    Several loose thoughts. (Bear in mind I know little about buildings, historical or otherwise, beyond vague general knowledge!)

    – You’d looking at features of the buildings, rather than just their age help? It seems clear some features simply can’t cope well. Tall brick chimneys are a very obvious case, but another I noted (anecdotally) while visiting was brick cladding in the inverted ‘V’ under the roof; I’m guessing many of the these have little tying them to the framework and simply fall out with sufficient shaking. One contrast I’m curious about is the Museum compared to the Arts Centre just across the road. The museum apparently is OK, whereas the Arts Centre has a lot of damage. Superficially these look to be built in a similar style and similar time.

    – What exactly do you mean by “the type of movement in the ground” that you wished were recorded?

    – Once comment I’ve seen (I can remember the source, or how sound it was) was that liquefaction issues (and hence issues with the foundations of many buildings) correlated with former stream beds. (By ‘former’ I’m pointing to that these have long dried up and aren’t visible as such, etc.)

    ‘David in Chch’

    – If the Wikipedia is correct, the 2008 Iwate-Miyagi Nairiku earthquake earthquake has an higher vector sum PGA of 4.36g than the recent Honshu earthquake. I added a comment about it on my article comparing the PGAs of the September and February earthquakes. (I should add a note in article itself… another job to do…)

    • Hi Grant,
      Bear in mind this is a simplistic reply…
      I am sure you get the point that the building issues are large and complex, but by looking at building features, construction techniques, foundation methods, materials use etc, which all change through time whether that be driven by fashion, latest materials innovation, available technologies, they all contribute to a buildings potential to survive or collapse, in a disaster or through natural degradation. They can also help in the assessment of a buildings stability, and guide future management and rebuild policies.
      Each material used in construction has an inherent decay potential, and the rate in which this occurs is dependant on the material itself or its species, such as wood. But this is then really complicated by (for example):
      – environmental variables (especially in heritage buildings) such as the effect of changes in relative humidity. moisture, light, temperature changes.
      – physical issues such as stress, strain and load,
      – alloy properties (particularly pertinent to modern buildings). Is the alloy physically strong, brittle, are their in inherent weaknesses in the alloy.
      Equally underlying geology and sediments contribute to potential to collapse. And it could be that the underlying geology of the Arts Centre and the museum are different and therefore the buildings have responded to the quake differently. Or the foundations are different, or at least piled to a different depth. It could be any number of factors unfortunately.

      What I have seen archaeologically, through the last 9000 years is that the inherent strength of materials often end up being responcible for its collapse. The combinations in which materials are found can further accelerate the collapse. Such as you say, bricks, tiles, stone are collapsed because of a weaker substrate such as mortar, plaster, or other adhesive. The other big cause of collapse is related to increasing stress, strain or load of structural materials, such as timber framing. As the cellulose content of wood disappears, the lignin skeleton remains, and one day because of stress, strain or load, ‘bang’ the wood goes. This occurs quicker when there are not enough supporting posts, and especially susceptible to damage through earthquake movement.

      Movement type – I wondered about the effect of short waves, long waves, up and down movement, shaking movement not fixed on a set axis. Does that make sense? Can something be said in the future about the effect of earthquakes of a certain type on sub surface arch remains? It may be that there have been just too many quakes in this current situation to enable this question.

      Regarding liquification and buried stream beds…sounds interesting, I will have to look into that further.

      All in all…in the understanding of why some buildings remain standing, some collapse…and ultimately what criteria or properties should be prioritised in any future rebuild…it is very compliex, and to be done to the best standards, specialists in many fields need to consult, including ensuring the heritage community and archaeologists are able to record and coalate as much info about the heritage buildings as part of this process. It is not a quick thing to achieve…and the inhabitants of Christchurch should actually be pleased about that. For their sake, the future policies and direction should be informed by the right data…not a quicky approach which leads to later, and hopefully unavoidable, problems.

      I have written this off the cuff this eve, and hope fits in with some of your loose thoughts Grant. Happy Easter!

  • More later (it’s late…) but in the meantime: the PGA measurements have two horizontal axes and a vertical axis; you can represent what they record several ways. I never did get time to dig into the data myself as I had hoped to* but there are summary graphs that separate the vertical and horizontal maximum PGAs in the Q&A that was put out (PDF file).

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