Anthony Vile explores earthquake proneness through the not completely settled dust of the Canterbury Earthquakes and Earthquake Royal Commission enquiry.
Three words have been rolling off the tongues of various building officials, building owners, engineers, insurance agents and developers of late … “Earthquake prone building.”
These three words have usurped the previously feared monster of “leaky building” to take the throne of most thorny built-environment issue. That is, if you consider housing supply to be an economic issue, retail to be a marketing issue and sustainability to be just too ‘last century’ to even warrant discussion.
If you take a holistic view it is easy to see the connections and see that the building industry and the built environment is going through some growing pains; hopefully on its way to becoming a lot more mature, productive and sustainable as a result. Read the Productivity Commission report on the sector and it’s even more apparent. The capacity for the sector to deliver innovation across the board is in question. Leaky buildings, skill shortages, poor planning for growth, developers struggling to solicit capital post-GFC, materials monopolies, architects struggling to retain relevance – it all adds up to a pretty grim picture.
Of course the promise of a rebuild in Christchurch and latent demand in Auckland jump starting another boom cycle keeps things positive, as do a few aspirational public projects spotted through the dust and debris post earthquake and GFC. Whyndam quarter in AKL, the urban planning and ongoing temporary and pop-up events in Christchurch, AKL art gallery extension, for example. It is only when threats are directed at personal safety, capital investments and forced spending that ears start flapping and mouths gibbering.
EQPB is nothing new to those working in the industry. It has been around at least since 2004 when the Building Act handed the mantle to territorial authorities to have a policy on dangerous, unsanitary and earthquake-prone buildings in place within 18 months.
In reality the issue has been around for a lot longer. Architects and engineers have been well aware of the threats posed by un-reinforced masonry buildings and liquefaction for a long time. The 1989 Loma Preita Earthquake in San Francisco is a case in point. Incidentally, the large stock of multi-storey NZ timber-framed townhouses in that city survived the event unscathed. It is a shame it has taken an event like Christchurch to turn up the heat on both urban design and earthquake safety in this country.
Post-Christchurch, with large-scale destruction of a good percentage of older commercial building stock in the CBD, the majority un-reinforced masonry, the earthquake-prone building issue has bubbled to the surface like liquefaction itself. Along with increased insurance costs, renewed demand for newer, safer building stock, and process hiccups, confusion has reigned.
The Earthquake Royal Commission post-Christchurch has been charged with independent investigation of the Christchurch event including implications to national policy regarding EQPB and the Building Act 2004. Mapping a strategy for creating safe buildings and urban environments based on knowledge gained via Christchurch so that territorial authorities, the public and building owners have confidence moving forward is no easy task. The strategy addresses some key points:
- What is the baseline for structural safety measured as a percentage of the current building code?
- Who is going to pay for potential upgrade work?
- What is the timeframe for any upgrade work to be carried out?
This is obviously of greater significance to those areas straddling shifty plate tectonics with significant collections of older commercial structures – Wellington, Hawke’s Bay, Wairarapa, Canterbury – and of less interest to those in the Northern regions where seismicity is not so much an issue as ‘affordable-city’.
To a certain degree Christchurch has reinforced what we already knew. Un-reinforced masonry, parapets and ornamentation not tied back to a main structure, ‘pounding’ from neighbouring buildings shaking at disparate speeds due to disparate mass and construction technology, building on fill or old river riverbeds – all make for significant danger. Part of the complexity of the issue is that private ownership creates potentially public danger.
The Earthquake Prone Building issue in singular terms is about safety and saving lives. It is attempting to address – based on best practice and best outcomes – how a building built prior to 1976 using the knowledge and technology of the time measures up against the current building standards. If it is deficient what are the options for alleviating risk – retrofit or demolition?
A building is considered earthquake prone if assessed to be less than 34% of the existing build code. The assessment is based on building age, type of construction, regional seismology and localised geotechnics and performance of structure under a moderate event. It does not apply to residential buildings.
Post-Christchurch, owners already stung by increased insurance and building costs, caught in the midst of a slow economy, and threatened with the possibility of structural upgrade work to an unconfirmed target percentage of today’s building code, have reacted cautiously.
In this climate, with little clarity in a market suddenly looking for certainty and safety, investors are rightly nervous. Some organisations, risk and cost adverse, have had no choice but to seek safer (read: newer) digs. When employees’ lives and the continuation of business through an event are at risk, then it makes complete sense. Unions tend to agree.
What does this mean to Hawke’s Bay?
We live in a highly active earthquake zone with urban settlement on large areas of land with a high liquefaction risk, both in Hastings and Napier. Heritage is both an economic generator and part of the city identity, more so in Napier than Hastings. Both councils have earthquake prone policy in place.
Hastings since 2006 has been progressing a “policy which actively seeks to identify buildings that are potentially earthquake-prone and allocate them a suitable priority, in order to take appropriate action to ensure they are made safe in reasonable time frames.” Words cloaked with good intention but perhaps no clear outcome. Going above the call of duty there is even an inventory of those currently ‘stickered’ online via HDC’s website, as well as those potentially stickered. The means of ascertaining earthquake proneness has been via a council-contracted desktop review of known information. Any owner can contest the outcome at their own cost.
The Hastings policy is under review as part of a five-year review cycle, timely given the Earthquake Royal Commission feedback and the district plan review.
Napier has been actively engaging with the issue also, revamping its policy this past May. It is clear about what,
when and who. The onus is on the building owner:
“…every owner of a building of 2 or more stories or single storey buildings with an eave height greater than 4 metres and are classified as a Place of Assembly as defined by the City of Napier District Plan constructed prior to 1976, with the exception of private single detached dwellings, is required to submit a written assessment of the earthquake proneness of their building to the Napier City Council.
The assessment must be undertaken and certified by a Chartered Professional Engineer (Structural). This assessment is to be completed within 12 months of this policy becoming operative.
The cost of the assessment of the earthquake proneness of the building will be met in full by the building owner.
If an assessment report is not submitted within this 12 month period the building will be deemed to be earthquake prone.”
Needless to say, engineers in the Bay have been very busy and building owners concerned. Architects have been relatively quiet on the issue locally, but the National Institute (NZIA) has a clear policy on heritage and has been actively contributing to discussion.
Realising the threat to the Art Deco Capital, the Art Deco Trust has positively and proactively organised and engaged with experts and the public.
Earthquake Commission steps in
Thankfully, the Earthquake Royal Commission has finally delivered its findings in a report – Volume 4 of the Canterbury Earthquake Royal Commission Report – with a total of 36 recommendations. Concurrently, the Department of Buildings through the Ministry of Business Innovation and Employment has released its own change proposals for consultation. Its document is titled Building Seismic Performance Proposals to improve the New Zealand earthquake-prone building system.
Some certainty is beginning to appear, bearing in mind that in an election year no government is going to drop a bomb of excessive cost-generating policy on their constituents. The government has taken on board many of the Commission’s recommendations, but has chosen longer timeframes and lower minimum standards for strengthening.
Local government and the free market have been shoulder tapped as the drivers for change. However, the free market and built heritage have had a terrible record over the years. Think 1980s Auckland.
Heritage buildings tell a local story but also a New Zealand story. As a region and nation we have to decide how important built heritage is bottom-line – we need some rationalization of what is valuable from a heritage point of view, from a national perspective, and some system of financial aid must be devised.
There are some clear and present threats to heritage in all this. For example, there seems to be some transfer of power from the NZ Historic Places Trust (NZHPT) to local authorities. Without the necessity to consult with the NZHPT on protected buildings, councils and developers would have carte blanch.
Although some high-level estimates have been put against the cost of upgrade, with 25,000 buildings and $1.68 billion bandied about, there is no actual accounting for the economic value heritage might create in a community, nor the stimulation to the economy brought about by the upgrade work. Whatever the final revisions to the Building Act, it is inevitable that some built heritage will be lost. When bean counters become the sole progenitor of urban development we need be worried, especially so if property value is cynically calculated as value of land less cost
Alternative financial approaches are not hard to find.
In San Francisco, the Mills Act is the single most important economic incentive in California for historic preservation. Property taxes are reduced – sometimes by 50% or more – in exchange for a ten-year commitment by the owner to make specific improvements to their building. There are many more examples from around the world for funding structures that support the retention of heritage. It is best to think of it as a positive opportunity to not only create more attractive, but also safer and more resilient and useful urban spaces, buildings, cultural stories and cities.
Thinking this broadly, we need to understand that heritage can be a value-adding proposition that can sit alongside new development – Napier City, case in point. That an adaptive reuse of an existing building can incorporate structural upgrades as well as environmental upgrades. That reuse of existing structure in the long-term is a far more sustainable, resource-conserving, low carbon path. Rightful consideration also needs to be given to the cultural story that the built heritage tells.
I imagine the report will elicit same old free market vs. protection naysayers debate. Property Council chief executive Connal Townsend has described proposed new standards as “hugely radical”. Whatever the final outcomes, there are important opportunities to consider:
- To redefine the cultural and economic value of heritage buildings nationally. Will a photograph suffice or do we need the real thing?
- To explore innovative ways of structural retrofit, both in terms of physical works, funding strategies and financial incentives.
- To piggyback energy upgrades and other ‘green’ initiatives on structural upgrade works.
- To take the opportunity to reconsider the traditional CBD function in a 21st century environment.
- To put people in employment and in training to have the required skills to complete the work and grow the economy.
- To plan for future urban growth and open space in a holistic proactive manner.
- To investigate design opportunities as well as engineering outcomes, and to advance research and innovation in the sector.
Wellington City Council, realising the potential, both positive and negative, of the issue, has investigated the prospect of financing through low-interest loans that are tagged to a property rather than a owner.
There is potential for local government to bear the cost of upgrade of public facilities of certain age, but in a time of fiscal conservatism this will require, as noted, some creative funding strategies. That said, in the case of public buildings there obviously needs to be rigor around safety; if money needs to be spent to save lives then it should be.
The same can be said for urban street spaces – public space put at risk by the actions of private owners whose buildings face them. In Christchurch un-reinforced masonry facades falling into the streets were the killer. The feasibility of groups of buildings carrying out upgrade work – as a way to share the load economically as well as physically – has been investigated. Where you draw the line regarding prioritization of upgrade work, and how big a stick councils get, will be two interesting outcomes of the commission report.
Earlier this year Victoria University students, sponsored by Wellington City Council, worked on a project to investigate the opportunities for an integrated approach to dealing with the earthquake prone building issue. They chose Cuba Street mall as the focus of their study working as a group to develop synergies between engineering and architectural solutions as well as between neighbours. They developed concepts reliant on whole block solutions rather than independent building solutions.
As well as showcasing the potential of collaboration and fresh talent, the project highlighted a valuable idea; the city is a collective entity. The individual elements contribute to a whole greater than its individual parts and petty politics. It’s an idea that has inspired cultures for thousands of years and forms the basis for a civil and democratic society. NIMBYism becomes ‘Working together for the greater good-ism’.
Anthony Vile, a regular contributor to Architecture NZ, is a designer and urbanist. His work ranges from residential architecture, public art and urban design to urban planning and cultural analysis. Completed formal architecture and urban design education in New York. Has taught design at Univ of Auckland School of Architecture and Planning and Unitec.