ChristChurch Cathedral and heritage important for city’s future

The demolition of the ChristChurch Cathedral’s spire is expected to begin on Monday.

On Saturday, I’ll be attending a rally, organised by Restore the Christchurch Cathedral and led by the Wizard, outside the Anglican Church’s Christchurch synod meeting. We are gathering from 8.15 am for a silent vigil and then for a rally from 10.30am outside St Christopher’s Church on Avonhead Road. The Wizard is leading another rally on Sunday outside the Canterbury Museum at noon.

The Restore the Christchurch Cathedral group have also launched an online petition calling for the restoration of the Cathedral.

ChristChurch Cathedral has long been more than a church. It is a city icon and major landmark.  It has sheltered many people of many faiths and been a place of dialogue, of music, art and creativity as well as reflection and prayer. The wider public needs to be involved in decisions about its future. We haven’t been because of CERA’s draconian powers and the way in which it can override and undermine decisions normally made by councils.

Denying the public a voice is profoundly disempowering, both for heritage and recovery.

ChristChurch Cathedral is a Category 1 historic place designed by two architects celebrated for their Gothic revival buildings, George Gilbert Scott from the UK and New Zealander, Benjamin Mountfort. It is built largely of Canterbury stone, including large basalt blocks, a reminder that volcanoes as well as earthquakes have shaped our landscapes. It is a crucial part of the city’s built heritage. With the Arts Centre, the Canterbury Provincial Chambers and the Canterbury Museum it forms a precinct of Victorian Gothic Revival buildings.

ChristChurch Cathdral and Cathedral Square before the earthquakes

In any other part of New Zealand, the demolition of a Category 1 historic building would almost certainly involve a publicly notified resource consent application under the RMA with the  public able to make submissions and if necessary, appeal the Council’s decision to the Environment Court.

The emergency period post quakes is long gone. Yet CERA’s powers continue to throttle democracy and deny community and public involvement in virtually all significant decisions about our place and our city of Christchurch.   Who makes the crucial decisions, and how and why is increasingly opaque. Since Minister Brownlee’s “old dungers” comment,  the public have been shut out and CERA has facilitated the destruction of Christchurch’s heritage character and identity.

International architects, engineers, stonemasons and organisations are offering their expertise, advice and funding support to help restore ChristChurch Cathedral. Engineers say that the Cathedral can be made safe and restored at a cost that is a lot less than the $100 million figure previously quoted by the Bishop.

Making safe and rebuilding the Cathedral would contribute to the city’s recovery. It would use the best skills of architects, artisans, stonemasons, engineers, fund raisers and many others from New Zealand and abroad.  It would show what we can achieve, rather than want we can’t.  It would be a project which would signify recovery far more than any cardboard edifice.

Allowing demolition crews and their diggers to make another blank and empty space in the city’s heart – Cathedral Square – would add to the ugly emptiness of the sites of the former Warner’s and Press buildings. It would impede recovery by causing more loss, and further destruction of memory and our sense of place.

Restoration will take time. Yet what’s the rush?  The  construction of Barcelona’s world renowned Sagrada Familia started in 1882. It was not consecrated until 2010 and is not expected to be completed until 2026, a century after the death of its architect Antoni Gaudi. Yet it is a World Heritage site used, visited and celebrated by thousands each year.

CERA needs to hit the pause button now on the demolition of ChristChurch Cathedral and other heritage buildings. We have lost so much already. There must be public discussion about options to retain the Cathedral and other buildings.

We can rebuild a progressive, beautiful and sustainable city. Knowing and celebrating our past helps creates a strong foundation for the future.

An online petition asking CERA to stop the destruction of Christchurch heritage buildings has also been set up. It calls for engineers, heritage architecture specialists, heritage groups and the citizens of Christchurch to have more time and a say in the fate of remaining buildings in danger of demolition.  You can add your voice to ours.

21 Comments Posted

  1. Well, at the risk of offending all; well done on defending the doctrine, I can see your beliefs shining through, bravo [slow clap].

    Most engineers today are more interested in pressing a button and getting a result they can blame on someone else if it comes to the crunch, while calling it innovative, scientific, and artistic – when in reality it’s more like belief, doctrine, and greed. Blasé attitude leading to situations like CTV is no surprise.

    So I’ll tell y’all what I really think 🙂

    Actually you guys do make valid points, which I was aware of. But fact is unreinforced concrete and unreinforced stone masonry are very similar. Both are composites in their own right, both made of the same stuff, both rely on compressive strength, and have approximately equal performance (comparing new with new and old with old).

    The options for engineering it (reinforcing, sizing, materials choice) to fit the job are not an innate property of concrete (vs masonry). Concrete is glued together stone after all. Masonry isn’t considered a composite material “as engineers understand it” because it’s not “modern”, therefore they don’t understand it (and as such it has fallen a long way behind in typical use).

    In my example, the concrete can only be held to the rebar by tensile and shear forces. Only the small portion directly above the rebar can be considered to be held there by compressive forces, unless there’s an external compressive loading through the bottom, which then falls back to a “simply held there by its own weight” argument. There is no “composite” magic. What’s the big difference between this and a beam up manually from stones, mortar and steel (apart from being “exposed aggregate”)?

    You can’t ignore the fact that both stone masonry and concrete structures are tons of rocks waving about in the air, glued together by the same stuff. To the point where some people are extremely nervous about concrete, and prefer wood construction (I’m the one who brought up the comparison with concrete in my first post). Yes reinforced concrete will compare favourably against unreinforced masonry, but so will a brand new building compared to one made 1000 years ago. Perhaps the “resilience” of these old stone masonry buildings is their (metaphorical) downfall in this comparison, because they will stand long after their mortar has given up the ghost (as do 2000 year old unreinforced concrete structures I must admit).

    Tall concrete structures flex because they are extremely spindly in comparison to a short building with structural walls, and are reinforced to take the relatively enormous tensile stresses required of this mode of construction. Other than that, reinforced stone structures flex and crack and fail in roughly the same way as concrete, and both experienced pretty horrendous collapses during the quakes (but for very different reasons).

    The preservationists are talking about something which is actually more advanced than reinforced concrete. Not just by introducing other materials like glass, carbon, and epoxy or whatever, but also in extremely well thought out detailing of the “reinforcing”. It should be no surprise that it can perform on par. The Cathedral already has reinforcing steel within its stone structure (when it was built), yes they were aware of the earthquake-prone history of this region. $7M spent on strengthening in 2007 IIRC. Note how it hasn’t fallen down, just the unreinforced tower and west wall – the one with the battering ram prop up against it and also tied into the roof (which all tore free, very obvious if you look at it). In fact it’s in pretty good nick considering what happened to it.

    Personally I can’t see the point of a “Disney” approach because it’s not honest, and a bit farcical when the original building is still standing. However this is a subjective and emotive decision and will depend on what people want and what they want to spend.

    Also the Anglican church doesn’t own the building (it has no equitable title to it, being held in trust), and there are donors lining up globally to pay for its restoration, but that’s a whole different story. I’d like to think the building can be stabilised and restoration left until people in dire need of housing are sorted (me being in that situation until a few weeks ago), but the church has no interest in social spending, they just want a new building.

  2. “My example above seems valid to me (if a little alarmist). The concrete outside of the rebar isn’t held there by magic, composite or not.”

    Without taking you through a whole composites engineering course.

    It is held there by the concrete which it is glued to, which is in turn, glued to the rebar. It can be engineered, by varying the amount, cross section and shape of each component, to have different stiffness, resilience, toughness and strength according to the requirements of the job.

    Masonry you are stuck with the qualities of the stone used.

    Masonry, on the other hand is simply held there by its own weight.
    It is not a composite material as engineers understand it.
    The buildings stay up because of the compressive strength of the pile of stones. The reliance on compressive strength can easily be seen with the flying buttresses in medieval cathedrals.
    Morter, in traditional masonry construction contributes little to the strength. Its function is basically to fill gaps in the fit of the stones so they stay sitting on each other, and for weatherproofing. Most well constructed masonry buildings would stand up equally well, without the mortar.

    I am the first to admire the engineering skills of the stonemasons, but it is not a good construction where there are large short term variable loads, such as earthquakes, from random directions.

  3. I agree about not trying to imitate the past.

    Napier. Which is now a tourist attraction, and rather an attractive city in its own right, is like that because they rebuilt it in the best of contemporary style.

    A couple gave up, on building a rather neat and original piece of contemporary architecture on the old library site in Lyttelton, because the council insisted it had to fit with the old Lyttelton style.
    A Lyttelton style that has resulted over the last few decades in rather boring cookie cutter modern houses, bastardised with colonial gables to meet, the requirements.

    A style which has all fallen down, anyway. Only the bottom half of one of the old stone buildings are left.

    I like the new container town styling apparent in places like Cashel mall.

    This is an opportunity for some new, unique and original architecture.

    In years to come we may see people coming from all over the world to look at container town, a very appropriate theme for Lyttelton, OR, we can have fake imitations of the old masonry buildings.

  4. Antony is overlooking one very important property of reinforced concrete. And that is the ability to flex. Tall reinforced concrete structures can move with wind, earthquakes and shifting loads.

    Stone masonry buildings cannot move for they would shake apart.

    Personally think the old CHCH cathedral was butt ugly and uninspiring.

    Knock the bugger down and put up something inspiring.

    Something that the owners can afford to put up.

    After all the Anglican Church has to front with the cash. Cash it may find better spent on social services than a monolithic monstrosity the rebuild cathedral would be if rebuilding to the old design.

  5. Thanks Kerry, exactly.

    Antony, The Preservationists aren’t talking about reinforced concrete, they are talking about gluing stones together somehow… the difference is enormous.

    I have no qualms about more modern reinforced concrete designs, but reinforced concrete is NOT masonry… it is not what the preservationists demand, and as shown by the collapse of the CTV building it is not anything like foolproof. A reinforced concrete building will NOT make any “preservationist” happy. That’s why I advocate the “Disney” approach. One can preserve the appearance and maintain historical continuity without the risk.

    What the preservationists demand is not in my opinion, reasonable in this instance. I am happy to preserve the past but I don’t accept massive added risks and expense to do so. Building in stone masonry, in a major earthquake zone, is lunacy. The people who built the Cathedral in the first place didn’t I think, realize the earthquake risk. Now that we do, repeating their mistake is… not wise.

  6. Kerry.

    Masonry is a composite.

    The combined strength and resilience of concrete and steel isn’t greater than that of the same volume of steel alone!

    Masonry benefits from the resilience afforded by the mortar (the ability to crack and heal, ductility, energy dissipation) that neither stone nor mortar posses on their own. In that manner it’s a lot more like glass reinforced plastic than concrete (bulk glass is brittle, bulk plastic has low strength and high creep, whereas steel is useful as a structural material in its own right).

    In a general sense of course I agree with what you say, but my original comment was about thinking out of the box, and challenging the double standard that people seem to apply when comparing stone masonry (especially) with concrete. People get bent out of shape about masonry by thinking of the components individually (as in “but stones can come loose!”), yet the same people will treat concrete as a bulk “composite” as if that affords it some magical qualities which make it much better. It may actually be in some cases, but that doesn’t change the mechanics of what’s going on. The stones don’t really know if they were poured or placed there by hand, nor do they know how any nearby tensile support got there. (This was my point about the Cathedral.)

    My example above seems valid to me (if a little alarmist). The concrete outside of the rebar isn’t held there by magic, composite or not.

    What we are taught is not always reasonable.

  7. Antony.

    Reinforced concrete is a composite.

    As a composite, the combined strength and resilience of concrete and steel is much greater than each of the two parts singly.

    As an engineering material, reinforced concrete has much more in common with glass fibre reinforced plastic than it does with stone masonry.

  8. bjchip, I don’t know if it’s poor form to drag up a thread like this (I can’t see why), but I saw this a while ago and have to comment.

    The flaw in your argument against stones and bricks being unsuitable for any building in Christchurch, is that concrete weighs the same. They built 25 story buildings out of that stuff. It has roughly the same compressive strength as stone, so needs about the same amount. In fact the tensile strength of concrete is usually less than stone (consider where concrete breaks – is it through or around the aggregate stones?). Reinforcing is a ‘detail’. Sure, it’s much cheaper to pour concrete around reinforcing, but this is a technical issue, not a matter of physics. At the end of the day, all pieces of concrete that are outside of the rebar are effectively “just hanging there”, like stone, but a little weaker.

    I wonder whether that strikes fear into the hearts of non-engineers as much as seeing a stone building?

  9. I agree with you fully Eugenie, it is time to call for a PAUSE on demolition and at the end of the day, do we want this iconic building which means so much to us ending up in Kate Valley Landfill (which doesn’t sound very green to me).

    Furthermore, we live in a democracy and I am so pleased that the Councillors have listened to the community.

    I hope to see you all at the rally on the 26th, may the Cathedral stand strong for my future children and their children.

  10. I’m sorry but there has been far too much money been spent on especially the cathedral and the entire centre city in general, there is still a huge housing shortage in Christchurch that should e getting the main focus but it’s not! Which would you prefer, having people on the streets with a cathedral or not having a cathedral and having people safe and warm in houses? Especially this time of year when people can die due to the cold. The cathedral nor the central city should be priority right now. Fix housing first then work on the central city. That’s exactly what the overseas experts are saying as well but does Gerry “pie-man” Brownlee seem to listen or care? No of course not. The way the whole so called recovery has been run is an absolute sham.

  11. Speaking as a born-and-bred Cantabrian I say, knock it down. We have more important things to spend money on than heritage. Heritage is a nice-to-have at best, but jobs and homes, both of which are severely lacking in Christchurch right now, are need-to-have.

    If rebuilding the Cathedral costs even as much as building a single home, I’d say it’s not worth it.

  12. What is it you wish to preserve. Is it the ambiance and soul that the Cathedral was, and really needs to be, or is it some meaninglessly exact stone-for-stone replacement of something that failed in the last earthquake?

    One thing is needed by Christchurch and that heart-of-the-city argument rings true. The other is not required, and should not be attempted.

  13. I think Meg, that the overseas engineers were talking out their collective rectums. I too am an engineer. Someone got the answer they wanted without asking the questions they needed to ask.

    You do not subject stone buildings to random 2G fields. Not if you wish to keep stones from falling. You keep stones from falling by NOT putting stones high enough to fall in the first place… which means NOT building anything that high with actual stone. Could one THEORETICALLY build that with enough drilling and reinforcing steel? Anchor every stone with enough rebar to hang the whole Cathedral upside down and shake it? Then maintain it to ensure that the attachments remain solid for the lifetime of the structure. Yeah… it is POSSIBLE but not at the prices quoted. Not at any price that this country can afford.

    I’d LOVE to have some word with those selected engineers about just exactly what they could design and build in that preservation effort, and get those explanations published because it would make it a lot harder for preservationists to advocate measures that WILL kill people.

  14. Thank you Eugenie for speaking at our rally. Our built heritage can in many ways be as important spiritually as our natural heritage. We have here a beautiful building constructed with craftsmanship and love, made with real respect for the trees felled and hillsides quarried for its construction. Many of us engineers know that it can readily and safely be repaired and strengthened to well in excess of our building codes (look up Miyamoto and Cardno). The demolition is proving crude and wasteful. No effort is being made to salvage the stone, which is irreplaceable since the Port Hills quarries are closed, and they look likely to chainsaw up the rimu and totara roof into firewood and splinters. The demolition of this building represents the loss of a much loved place and a powerful symbol of this city. For a person returning after many years away this building says ‘this is home’. The demolition is also a horrific waste of craftsmanship, materials and embodied energy.
    We have no idea what the church will build, but their buildings constructed after the 1950s do not bode well. I cannot condone the needless destruction of something I know to be glorious in the vain hope that we might (but probably won’t) get something better. Some of us are looking forwards to a ‘modern’ city, but not all of us find gleaming metal and glass especially meaningful. We certainly cannot afford to build our architecture in response to the latest fashions, as the natural resources involved in replacing unfashionable buildings are now far too precious. I fear that much of our rebuilt city (and perhaps a new cathedral) will repeat this mistake.

  15. In response to BJ: Do you think that the overseas engineers who recommended that the cathedral be saved were not taking into account the earthquake-prone nature of Chch as part of their analysis?

  16. To many of us who live here, that Cathedral represents a time we’d like to get past. To many of us, it being pulled down is the beginning of a new Christchurch.

  17. First: There is no indication whatsoever of what the Anglican Church would like to replace the Cathedral with. I would like to know that before I even THINK about protesting. A blank space is unlikely to be what the church is actually planning.

    Second: Christchurch is a city where it should be illegal to carry a brick up a ladder. There is NO way to build safely with stone or masonry in that location. People who build “to code” and think they are safe are deluding themselves. Low mass, flexible and strong is the rule. It ought not be challenged on account of a desire to make things as they were.

    Third: The Cathedral IS demolished already. It is of no use to anyone in its current form. It has to be taken down to the point where what remains cannot fall down. As a matter of physics and logic, you cannot fall off the floor. No matter how drunk the ground beneath you gets.

    Overall I am not impressed with preservation efforts that WILL put lives at risk. Yet this much is correct… the city needs its heart replaced… and soon. There is a solution to this. A “Disney”. Those who have been there know that the stones in Disneyland are seldom what they seem. The structure under them is steel. They don’t fall down in Earthquakes. Building a useful building inside the shell of a replica of the Cathedral would give the city back the heart it needs WITHOUT putting people’s lives at risk. Using the old real stone for the bottom 2 meters would make it difficult to recognize the difference.

    There is no way however, that the stones of ANY of that building can be more than 2 meters off the ground.


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