Building Seismic Performance

Transcription

1 Building Seismic Performance Proposals to improve the New Zealand earthquake-prone building system Consultation document

2 Minister s Foreword The destructive earthquakes in Canterbury have highlighted the need to review and improve the system dealing with earthquake-prone buildings in New Zealand. It is estimated that New Zealand has between 15,000 and 25,000 such buildings, representing around 8-13 per cent of all non-residential and multi-unit, multi-storey residential buildings. This consultation document proposes significant changes to New Zealand s earthquakeprone building system. They are broadly in line with the recommendations of the Canterbury Earthquakes Royal Commission in Volume 4 of its final report, delivered to the Government on 10 October 2012 and publicly released on 7 December This consultation exercise will inform the Government s response to the full Royal Commission report. The Government expects to deliver this in early to mid We need your views to ensure our earthquake-prone building policy is a robust and workable balance for New Zealand though we must be realistic about what is practical and affordable. The Government is mindful of the potential cost that will be put on owners due to the requirement to strengthen earthquake-prone buildings, so we only want to impose additional costs where it is necessary to do so. We must ensure the earthquake-prone building system strikes an acceptable balance between protecting people from serious harm and managing the huge economic costs of strengthening or removing the most vulnerable buildings. Regardless of the outcome of this process, it s important that New Zealanders have good information about the buildings they live and work in so they can make informed decisions. This Ministry of Business, Innovation and Employment consultation document looks carefully at all aspects of the earthquake-prone building system, including the risks, costs and benefits associated with alternative strengthening options and timeframes. I encourage you to read through the proposed changes and have your say through the online response process. We want the proposals to be well debated, because it s important the final decisions are well understood and supported. The decisions we take following this consultation exercise could save lives if and when the next big earthquake strikes. Hon Maurice Williamson Minister for Building and Construction

3 Contents Introduction... 1 Purpose... 1 The MBIE Review... 1 The Canterbury Earthquakes Royal Commission... 2 Other issues... 2 How to have your say... 3 What happens next... 3 Contacts... 3 Summary... 5 Proposals... 5 Background... 5 Current system... 6 Section 1: Background... 7 Understanding earthquake risk... 7 The Canterbury Earthquakes... 9 Section 2: Current System How the current system works How big is the problem? Costs and benefits of strengthening Problems with the current system What would a better system look like? Section 3: Proposals Compulsory seismic capacity assessment of buildings Public register A mandatory national requirement Enforcing the mandatory national requirement Exemptions and time extensions Roles, advice, information and education Section 4: Other Issues Strengthening and other Building Act upgrade requirements Heritage buildings...33 Inclusion of all residential buildings Feedback Form Proposals and questions Other questions...50

4 Introduction Purpose The Ministry of Business, Innovation and Employment (MBIE) is seeking comments on proposals to improve the earthquake-prone building system. The proposals were prepared to enable a timely Government response to the recommendations of the Canterbury Earthquakes Royal Commission covering earthquake-prone building policy. The proposals set out a consistent national approach for dealing with earthquake-prone buildings. For a definition of earthquake-prone building, see How the current system works (page 11). In essence, the proposals require: all non-residential and multi-unit, multi-storey residential buildings to have a seismic capacity assessment within five years of the changes taking effect, with this information to be made publicly available on a register all earthquake-prone buildings be strengthened, or demolished, within 15 years of the changes taking effect, compared to an estimated 28 years (on average) under the current system The 15-year timeframe comprises up to five years to complete the seismic capacity assessment, followed by up to 10 years for strengthening or demolition. This consultation document aims to help potential submitters understand the proposals. It lists the proposals and a set of questions about them. It also includes background information on earthquake risk, and a description of the current system. MBIE wants to hear views from the wider community about the proposals. It also wants to hear from people directly involved with the earthquake-prone building system, to draw on their practical knowledge and experience in order to fully understand any implementation issues. The MBIE Review The proposals in this consultation document result from a review of the earthquakeprone building policy system carried out during 2012 by officials from the former Department of Building and Housing (now MBIE). The review covered the legislative basis for dealing with earthquake-prone buildings, set out in the Building Act 2004, as well as the administration of the system by central and local government. The review process included input from experts in applying earthquake-prone building policy, including local government, building owners, engineers, building construction, heritage buildings and insurers. More information on the review process, including the terms of reference, can be found here 1 Building Seismic Performance - Consultation document - December 2012

5 The Canterbury Earthquakes Royal Commission The proposals in this consultation document were prepared to contribute to a timely Government response to the recommendations of the Canterbury Earthquakes Royal Commission. Decisions taken on these proposals will form part of the Government s full response to the Royal Commission report. The Royal Commission s report Part-Two covering earthquake-prone buildings policy (Volume 4) was released publicly on 7 December The Royal Commission s recommendations are broadly in line with the MBIE review proposals, although its recommendations go further in some areas. This consultation document identifies the Royal Commission s key recommendations and notes where they are in line with these proposals and where they are not. MBIE welcomes feedback on these proposals and on the Royal Commission s recommendations. Key Royal Commission recommendations that differ from the MBIE review: Residential buildings individual local authorities to be able to require strengthening of hazardous elements in residential buildings (most residential buildings are not currently covered by the earthquake-prone building system). Unreinforced masonry buildings faster timeframes for assessment (within two years) and strengthening (within seven years). Higher strengthening levels (to 50% of new building requirements) for certain parts of unreinforced masonry buildings (chimneys, parapets, ornaments and external walls). Local authority powers giving local authorities the option of requiring strengthening to be done faster and/or to higher levels than those set by central government, after consulting with communities. The Royal Commission report on earthquake-prone buildings policy also addresses issues that are outside the scope of the earthquake-prone buildings system. These issues are being considered by MBIE under separate work programmes. Other issues Views are sought on whether the current Building Act fire escape and disability upgrade requirements are, in practice, a barrier to building owners deciding to carry out earthquake strengthening work. Views are also sought on how important heritage buildings can be preserved, while also being made safer. Building Seismic Performance - Consultation document - December

6 How to have your say Please make your submission online if possible, to this address: Written submissions will also be accepted, using the feedback form appended to this document. Questions to prompt consideration are also included in the document following an outline of each proposal. Submissions on some or all of the questions are welcome. The consultation process runs until Friday 8 March To assist responses, regional public information meetings will be held during February. They will include a short presentation on the earthquake-prone building system and the proposals, followed by questions. The regional public information meetings will be publicised online and through newspaper advertising. A current meetings schedule can be found at: Note that this schedule will be updated regularly. Meetings will also be arranged with stakeholder groups directly involved with implementing the earthquake-prone building system. All submissions are subject to the Official Information Act. What happens next After the consultation period finishes, MBIE will analyse feedback and submissions and report to the Government for it to make decisions. If adopted, the proposals will require legislative change this will provide further opportunity for public input through the normal select committee process. MBIE will work closely with local authorities and others to ensure smooth implementation of any changes. MBIE will also carry out public information and awareness-raising to support such changes. Contacts For further information refer to or epbreview@dbh.govt.nz. 3 Building Seismic Performance - Consultation document - December 2012

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8 Summary Proposals 1. Local authorities would be required to make a seismic capacity assessment of all non-residential and multi-unit, multi-storey residential buildings in their districts within five years of the legislation taking effect, using a standard methodology developed by central government, and to provide the resulting seismic capacity rating to building owners. An owner could have their building s seismic capacity rating changed by commissioning their own engineering assessment. 2. Assessments would be prioritised faster for certain buildings (eg, buildings on transport routes identified as critical in an emergency). 3. Building information would be entered onto a publicly accessible register maintained by MBIE. 4. The current national earthquake-prone building threshold (one-third of the requirement for new buildings, often referred to as 33 per cent NBS) would not be changed. However, it is proposed to establish a mandatory national requirement for all buildings to be strengthened to above the current threshold, or demolished, within a defined time period. 5. All buildings would be strengthened to be no longer earthquake-prone, or be demolished, within 15 years of the legislation taking effect (up to five years for local authorities to complete seismic capacity ratings, followed by 10 years for owners to strengthen or demolish buildings). 6. Strengthening would be carried out faster for certain buildings (eg, buildings on transport routes identified as critical in an emergency). 7. Owners of buildings assessed as earthquake-prone would have to submit a plan for strengthening or demolition within 12 months. 8. Certain buildings could be exempted or be given longer time to strengthen, eg, low-use rural churches or farm buildings with little passing traffic. 9. Central government would have a much greater role in guiding and supporting local authorities and building owners, as well as in public education and information. Background The risk of major life-threatening earthquakes remains very low in New Zealand. The risk of dying in an earthquake is around one in a million annually, averaged across the whole population, compared with a one in 10,000 risk of dying in road accidents. There is no such thing as an earthquake-proof building any building may fail if the earthquake is big enough. Therefore, the system must strike a balance between protecting lives and the economic costs of strengthening or demolishing the most vulnerable buildings. 5 Building Seismic Performance - Consultation document - December 2012

9 Current system The Building Act 2004 (The Act) defines an earthquake-prone building as being likely to collapse in a moderate earthquake. A moderate earthquake is one-third as strong as that used in the design of a new building on the same site. The Act gives local authorities the power to identify and require strengthening or demolition of earthquake-prone buildings. Local authorities must develop their own policies for dealing with earthquake-prone buildings. The earthquake-prone building system covers all non-residential buildings, and multi-unit, multi-storey apartment buildings that are two or more stories high and have three or more household units. Other domestic buildings are excluded. There are between 15,000-25,000 earthquake-prone buildings in New Zealand. This is a ballpark estimate because very few local authorities can provide good data. Under the current system, many earthquake-prone buildings are not being identified or dealt with in a timely and cost-effective way. The issues include too much variance in local authority practice, public confusion about risk, a lack of good data on buildings, and lack of central guidance to local authorities. Ideally, in an improved system, no building would fall below an acceptable level of risk. There would be better information on the seismic capacity of buildings, reasonable times for owners to strengthen or remove buildings, limited exemptions to the strengthening requirement, and important heritage buildings would be preserved. Building Seismic Performance - Consultation document - December

10 Section 1: Background Understanding earthquake risk New Zealand is a seismically active country. We live with the risk of earthquakes and must prepare for them. Fortunately, major life-threatening earthquakes are very rare. Outside of Canterbury, earthquake risk has not changed in New Zealand since the Canterbury events. But when they occur, major earthquakes are devastating for communities, as the Canterbury experience has shown. With the lessons of Canterbury relatively recent, now is a good time to consider what changes may be needed to the system controlling the seismic performance of New Zealand s stock of around 193,000 non-residential and multi-unit, multi-storey residential buildings. Currently, buildings are only subject to earthquake-prone building requirements if they are likely to collapse in a moderate earthquake. A moderate earthquake is defined as generating shaking at a building site that is one-third as strong as what a new building at the same site would be designed to withstand. A building s seismic performance is affected by many factors, including its construction for example, older, unreinforced masonry buildings are much less likely to withstand earthquakes than modern buildings. People in or near these buildings face higher risk of death or injury in an earthquake. A typical new building, for example a hotel, office building or apartment building, is designed to resist a one-in-500 year earthquake. The actual strength of a one-in-500 year earthquake varies around the country such an event in Wellington would be significantly larger than in Auckland. Because of this, new buildings in higher seismic risk areas like Wellington are stronger than in other, lower-risk parts of the country. New Zealand Society for Earthquake Engineering (NZSEE) guidelines suggest that earthquake-prone buildings are at least 10 times greater risk to occupants than a new building. The risk of dying from earthquakes is relatively low compared to other risks we face in our daily lives. Figure 1 (page 8) shows that, averaged across the whole population, the annualised individual fatality risk from earthquakes is around one in a million. This is much lower than, for example, the risk of dying in road accidents (around one in 10,000). 7 Building Seismic Performance - Consultation document - December 2012

11 Figure 1: Fatality risks from earthquakes and other hazards Note: The risk estimates above use experience-based data averaged across the whole population over long time periods. Altogether, 483 people are recorded as having died in earthquakes in New Zealand since All but 42 died in the two catastrophic earthquakes in Napier in 1931 (256) and Christchurch in 2011 (185). By contrast, around 37,000 people have died in road accidents, with 1,125 fatalities in just the three-year period from 2008 to While they are rare, earthquakes differ from other risks because of the high death toll and impact that individual earthquakes can wreak on communities. Even though more people die in road accidents than earthquakes, most fatal road accidents involve fewer than four deaths per event. New Zealand s worst single road toll was 15 people killed in a bus accident in Northland in Existing buildings can be strengthened to withstand moderate to large earthquakes, but the financial costs are often large relative to the benefits, which are small on an annualised basis, and may not be realised for many years (if at all). Building Seismic Performance - Consultation document - December

12 Furthermore, safety can never be guaranteed. There is no such thing as an earthquakeproof building any building may fail if the earthquake is big enough. Therefore, designing an earthquake-prone building system involves balancing life and safety considerations, on the one hand, with the economic cost of dealing with risky buildings on the other. The optimal balance might be described as an acceptable level of risk. Strengthening above this level has additional benefits, including reduced damage to buildings and faster recovery of communities. A fuller discussion of the risks associated with earthquakes, and the implications for policy-making, can be found in the report A Risk Framework for Earthquake-Prone Building Policy ( by UK risk management expert Tony Taig. His report was commissioned for the MBIE review. The Canterbury Earthquakes The Canterbury earthquakes were unusual in their size, large number and ongoing frequency. Since the first large earthquake on 4 September 2010, Canterbury has endured more than 10,000 earthquakes and aftershocks. The forces from the 22 February 2011 earthquake were much bigger than those new buildings are designed to withstand the Institute of Geological and Nuclear Sciences (GNS) has equated them to a one in 2,500 year seismic event. 1 Given the extreme severity of the 22 February earthquake, the city s buildings generally performed well in terms of protecting life. The number of deaths and injuries was large, although lower than might have been expected from such a massive event. Most buildings in Christchurch were sufficiently resilient for their occupants to get out of them alive. Of the 185 people that died as a result of the 22 February earthquake: 133 died as a result of the collapse of two large buildings, Canterbury Television and Pyne Gould Corporation 35 died as the result of facades or walls of unreinforced masonry buildings collapsing onto footpaths and roads four were killed inside an unreinforced masonry building three were killed by other structures falling onto them (a chimney breast, a freestanding wall and a concrete spandrel from a car park building) 10 died for reasons not related to building failure, including rock fall The Canterbury Earthquakes Royal Commission heard considerable detailed evidence about specific building collapses and has made recommendations based on lessons from those failures. This consultation document notes only those Royal Commission recommendations that are relevant to earthquake-prone building policy. The Government will make a full response next year to all the Royal Commission s recommendations. 1 See Spectra and Pgas for the Assessment and Reconstruction of Christchurch, GNS paper to 2012 New Zealand Society for Earthquake Engineering Conference, 9 Building Seismic Performance - Consultation document - December 2012

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14 Section 2: Current System How the current system works Past governments have made decisions to reduce the chances of buildings collapsing and killing or injuring people in earthquakes. The Building Act 2004 (the Act) defines what an earthquake-prone building is and gives local authorities duties and powers to require strengthening or removal of them. Central government provides some advice and guidance to local authorities on developing their own earthquake-prone building policies, but it lacks power to require local authorities to identify these buildings or take action against their owners. An earthquake-prone building is one that is likely to collapse in a moderate earthquake. A moderate earthquake is defined as generating shaking at the building site that is one-third as strong as what a new building at the same site would be designed to withstand. In practice, this definition has become condensed over time to the shorthand of one-third or less of New Building Standard, or NBS. The Royal Commission recommends moving away from the expression New Building Standard. Further explanation of this can be found in Volume 4, section 6.2.4, page 186 of the Royal Commission s final report. MBIE officials will consider this recommendation as part of a separate work programme. The Act gives local authorities powers to require owners to strengthen or demolish earthquake-prone buildings. This includes the power to enter buildings to determine whether they are earthquake-prone, and to require owners to reduce or remove any dangers. Owners who fail to comply commit a criminal offence punishable with a fine of up to $200,000. Local authorities also have powers to strengthen or demolish buildings themselves if an owner refuses to do so. The Act requires local authorities to develop policies on how they will identify and deal with earthquake-prone buildings in their areas, in consultation with their communities. These policies must be reviewed every five years, and any amended policy must be provided to MBIE. The earthquake-prone building provisions cover all non-residential buildings, including those for commercial, industrial or public use. They also include other structures, such as bridges, statues and memorials. Most residential buildings are excluded, except buildings that are two or more storeys high and have three or more household units. 11 Building Seismic Performance - Consultation document - December 2012

15 How big is the problem? It is estimated that there are between 15,000 and 25,000 earthquake-prone buildings in New Zealand. This estimate is based on a survey of all local authorities conducted for the MBIE review. The survey involved an initial questionnaire supplied to 66 local authorities, with follow-up conversations to elaborate on the information provided. The estimate is very broad because of the sparse data provided. Of the 66 local authorities, only 23 were able to provide any information on the number of earthquakeprone buildings in their districts, and much of the information received was incomplete. As a result, the estimate is extrapolated from information provided by a small number of local authorities. Although local authorities are required to develop policies for dealing with earthquakeprone buildings in their districts, they have complete discretion as to how actively they identify and deal with these buildings. Figure 2 (page 13) indicates the total number of pre-1976 buildings in each local authority district, provided by Quotable Value (green boxes) and, where provided, local authority data on earthquake-prone building stock (coloured columns). Better information is needed about the scale of the earthquake-prone building problem across New Zealand in order to identify and confirm costs, and to help policy-makers and the public understand and respond to the issue. Building Seismic Performance - Consultation document - December

16 Figure 2 Quotable Value and local authority information on building stock 13 Building Seismic Performance - Consultation document - December 2012

17 Costs and benefits of strengthening As part of the MBIE review, economic modelling was done on the costs and benefits of strengthening New Zealand buildings to different levels of seismic capacity. Earthquake strengthening of buildings leads to immediate and longer-term benefits, both direct and indirect. These benefits accrue to building owners and occupiers, as well as to insurers and wider society. They include: reduced fatalities, injuries and property damage costs resulting from earthquakes reduced social costs and impacts associated with earthquakes improved post-earthquake functioning of towns and cities and reduced economic losses. Some of these benefits are difficult to quantify, such as reduced social costs (eg, displaced households, loss of historic buildings) and improved post-earthquake functioning of towns. But they can be very significant, as has become clear following the Canterbury earthquakes. Earthquake strengthening also has costs, for building owners (eg, design, consent and strengthening), local authorities (eg, identification, enforcement, information, education and monitoring), and central government (eg, education, monitoring and technical information). These proposals may bring forward decisions about certain buildings. Strengthening some earthquake-prone buildings may not be viable and demolition may be the only practicable option. Communities with many unstrengthened older buildings may be especially impacted. There is also a risk of lack of capacity within the building and construction and design sectors and local government to implement the proposals. It is important to note that some of the identified benefits, costs and risks would also arise without any change to earthquake-prone building policy, especially as local authorities have generally become more active in dealing with earthquake-prone buildings. Table 1 (page 15) compares indicative estimates of the direct benefits of reduced fatalities, injuries and property damage with the direct costs of strengthening under a range of scenarios. In summary, the table shows that, based on a strictly economic analysis, there is a large net cost to strengthening all buildings relative to the benefits of reduced deaths and injuries. This cost increases significantly when strengthening is done faster, or to a higher level than just above the current earthquake-prone building threshold (33 per cent of the requirement for a new building). Strengthening all buildings so that they are no longer earthquake-prone under the current system (estimated to take 28 years on average under current local authority policies) would indicatively involve a net cost of $933 million. Strengthening all buildings so that they are no longer earthquake-prone under the proposed system (15 years) would indicatively involve a net cost of $1.68 billion. Building Seismic Performance - Consultation document - December

18 Table 1 Summary of indicative direct cost/benefits of alternative strengthening and timing options Benefit Cost Net All figures = $M net present value Cost/benefit to achieve 34% NBS under the current system (average 28 years) Cost/benefit to achieve 34% NBS under the proposed system (15 years for all buildings) 37 1,717-1,680 Other options: Cost/benefit to achieve 67% NBS for all buildings in 15 years 89 7,692-7,603 Cost/benefit to achieve 34% NBS for all buildings in 10 years 47 2,194-2,147 Cost/benefit to achieve 67% NBS for all buildings in 10 years 114 9,829-9,715 Cost/benefit to achieve 34% NBS for all buildings in 5 years 60 2,798-2,738 Cost/benefit to achieve 67% NBS for all buildings in 5 years ,533-12,388 Note: These figures are midpoint estimates based on extrapolated local authority data and are indicative only. Benefits are affected by the probability of a major seismic event occurring (MM8 to MM11 earthquakes have been modelled taking into account their respective probabilities in each local authority), and are discounted over 75 years. The estimates do not take account of the flow-on benefits of strengthening, such as reduced social costs and impacts, improved post-earthquake functioning of cities and towns, or reduced economic losses. These flow-on benefits can be significant at higher strengthening levels. 15 Building Seismic Performance - Consultation document - December 2012

19 Problems with the current system Both the Royal Commission s report and MBIE s review found problems with current earthquake-prone building policy and its administration by central and local government agencies. As a result, many earthquake-prone buildings are not being dealt with in a timely and cost-effective way. The issues include: Too much variability in local practice individual local authorities have very different approaches to implementing current policy requirements. Some local authorities are not actively identifying earthquake-prone buildings or requiring building owners to deal with them. Other authorities have taken some action, but have given building owners very long timeframes to resolve problems. A number of authorities have taken strong action, including requiring higher strengthening than required by law. Variable approaches have been taken by local authorities to managing heritage buildings. Generally, however, local authorities have been more active in dealing with earthquake-prone buildings since the Canterbury earthquakes. Public confusion about risk poor understanding of the risks posed by earthquakeprone buildings and how these compare with other risks commonly faced in life. Lack of good data poor information on the number and specific location of earthquake-prone buildings across the country, due to inadequate data collection. Poor information on individual buildings information on building strength is not widely available or easy to find and use, making decision-making difficult for local authorities, building owners and building users. Inconsistent market responses because information on building strength and public understanding of the risks associated with buildings of different strengths is poor, the property and rentals markets have responded inconsistently sometimes too cautiously, sometimes not cautiously enough but often with little direct reference to the actual risks posed by individual buildings. Lack of central guidance central government has provided limited information and guidance to local authorities to support good practice and decision-making in support of stronger buildings. A related problem is limited central monitoring and oversight of the sector. Building Seismic Performance - Consultation document - December

20 What would a better system look like? The ultimate aim of an improved earthquake-prone building system is to reduce the risk of people dying or being injured in future earthquakes. Key features of a better system might include: Achieving acceptable risk public confidence that the risk posed by buildings in earthquakes is being managed down to a widely acceptable level. This recognises that the risk of building collapse, death and injury in earthquakes can be reduced but never eliminated. Therefore, the benefits of any reduced risk need to be kept in proportion to the costs of strengthening and removing buildings. Better, more accessible information building owners and users need good information to make decisions on the buildings they own and use. Over time, this will ensure continuing market pressure on owners to strengthen and replace older buildings. Reasonable response times strengthening or removing buildings can be costly and disruptive for individual building owners and communities alike. While earthquake-prone buildings need to be dealt with, this must be done at a pace they can reasonably manage. Limited exemptions while public safety must be the over-riding objective, a case could be made to exempt certain buildings from earthquake-prone building requirements. This might include low-use buildings in areas with little passing traffic. Important heritage buildings preserved many older, earthquake-prone buildings have considerable cultural and historic importance to communities. Again, while public safety must be the over-riding objective, special consideration must be given to how our significant heritage places can be preserved. 17 Building Seismic Performance - Consultation document - December 2012

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22 Section 3: Proposals Compulsory seismic capacity assessment of buildings Proposal 1: Local authorities would be required to make a seismic capacity assessment of all non-residential and multi-unit, multi-storey residential buildings in their districts within five years of the legislation taking effect, using a standard methodology developed by central government, and to provide the resulting seismic capacity rating to building owners. An owner could have their building s seismic capacity rating changed by commissioning their own engineering assessment. Proposal 2: Assessments would be prioritised faster for certain buildings (eg, buildings on transport routes identified as critical in an emergency). - Currently, local authorities decide whether and when to assess buildings for seismic capacity. It is proposed to amend the Building Act to require each local authority to assess the seismic capacity of all non-residential and multi-storey, multi-unit residential buildings in its district. To do this, each local authority would have a legislative obligation to assess buildings to identify those at risk of collapsing in moderate earthquakes. Each local authority would be required to assess all buildings covered by the earthquakeprone buildings system in its area within five years of the law change taking effect. Local authorities would be required to prioritise their assessments to initially assess those buildings: located on transport routes identified as critical in an emergency with important public, social and economic functions (such as schools and police stations) with post-earthquake recovery functions, such as civil defence centres and hospitals Seismic capacity assessments would be done by local authority staff or contractors, using a profiling methodology developed by MBIE, based on the known performance of buildings in earthquakes. The assessments would draw on existing local authority information about individual buildings, as well as easily observable building characteristics. The assessments would consider the building s age, design and construction method, location, use and any strengthening work already completed. It is expected that the seismic capacity assessments would quickly identify buildings that are likely to be earthquake-prone. We note that some local authorities have already completed a similar assessment process, or are doing so. 19 Building Seismic Performance - Consultation document - December 2012

23 The local authority assessments would compare each building s seismic performance relative to that required of a new building at the same site. After these assessments were completed, local authorities would advise building owners of the building s seismic capacity rating. The rating would be on a standardised national scale, to be developed by MBIE in consultation with relevant technical experts. Owners who disagreed with their seismic capacity rating would be entitled to request a change by providing further information about their building s seismic capacity. This would likely require further assessment of the building by an engineer, at the owner s expense. An assessment methodology would be developed by MBIE, based on engineering knowledge and experience about the performance of buildings in earthquakes. Local authorities would consider the additional information and change the seismic capacity rating to match the assessment, if appropriate. The Royal Commission recommends that local authorities complete assessments within two years of the effective date of the law change for all unreinforced masonry buildings in their districts, and within five years of the effective date of the law change for all other potentially earthquake-prone buildings. (Recommendation 82, Vol. 4, Final Report) Questions: 1. Should local authorities be required to assess the seismic capacity of all buildings covered by the earthquake-prone building system in their areas and to issue seismic capacity ratings to owners? 2. Do you think five years is a reasonable and practical time to require local authorities to carry out assessments in their districts? 3. Should unreinforced masonry buildings be assessed faster than other buildings? 4. What cost and other implications do you see with these proposals to assess the seismic capacity of buildings? Building Seismic Performance - Consultation document - December

24 Public register Proposal 3: Building information would be entered into a publicly accessible register maintained by MBIE. It is proposed that seismic capacity information on individual buildings be entered into a publicly accessible central register, to be maintained by MBIE. Local authorities would be required to enter the seismic capacity ratings of buildings into this register. This information would be from the seismic capacity assessment, and could be updated if further information were provided by the owner. MBIE would administer the register and make it easily and freely available to the public. For instance, information on the register could be made accessible by smart phone applications, so that building users could quickly and easily gain information on their safety in an earthquake. It is possible that other information could be added to the register, such as any identified structural weaknesses or features, or any actions agreed between owners and local authorities about dealing with earthquake-prone buildings. However, collecting this information would have a cost. Questions: 5. Do you agree that local authorities should be required to enter information on the seismic capacity of buildings into a publicly accessible central register to be managed by MBIE? 6. Should information other than the building s seismic capacity rating be entered into the register for example, agreed strengthening actions or information from an agreed building ratings system? 7. Rather than a central register, should local authorities be responsible for both collecting and publishing this information? 8. Should there be any other information disclosure requirements for example, should building owners be legally required to display information on the building itself about the building s seismic capacity? 9. What costs and other implications do you see resulting from the proposal to put seismic capacity information in a register? 21 Building Seismic Performance - Consultation document - December 2012

25 A mandatory national requirement Proposal 4: The current national earthquake-prone building threshold (one-third of the requirement for new buildings, often referred to as 33 per cent NBS) would not be changed. However, it is proposed to establish a mandatory national requirement for all buildings to be strengthened to above the current threshold, or demolished, within a defined time period. As discussed earlier (see Understanding earthquake risk, page 7), setting the earthquake-prone building threshold involves balancing life and safety considerations, on the one hand, with the economic cost of dealing with vulnerable buildings on the other. The optimal balance might be described as an acceptable level of risk it is the seismic capacity level below which the risk to occupants or those nearby is generally agreed to be unacceptable. There is no correct answer to what is an acceptable level of risk. On balance, taking account of risks and the costs and benefits of strengthening or removing buildings at different seismic resistance levels (see Costs and benefits of strengthening, page 14), maintaining the existing threshold at 33 per cent of the requirement for a new building is regarded by the MBIE review as appropriate. The Royal Commission reached the same conclusion in Volume 4 of its final report. Setting the national threshold at a higher level, for example 67 per cent, would have some additional safety and other benefits, but would also result in substantially greater costs and risks. The cost impact would be especially heavy for communities with large numbers of older buildings. Under these proposals, there would be a mandatory national requirement for owners of earthquake-prone buildings to strengthen their buildings to at least the current earthquake-prone building threshold, or to demolish them, with the timeframes and strengthening levels to be established by central government. This is based on the principle that government has a legitimate interest in legislation and regulation that protects public safety. But any strengthening above the current earthquake-prone building threshold, while clearly desirable, becomes more about preserving buildings from earthquake damage than life and safety considerations. Decisions by building owners on strengthening above the earthquake-prone building threshold would be driven primarily by market demand. Higher public awareness and disclosure of seismic capacity ratings would lead to a better-informed market. Current market experience indicates that buildings with higher seismic capacity are earning premium rentals. Better market information is likely to reinforce this trend, creating an incentive for building owners to invest in buildings that perform better in earthquakes. Building Seismic Performance - Consultation document - December

26 It is proposed that requirements to deal with buildings under the threshold should take priority over other legal, regulatory and planning requirements, such as those designed to protect buildings of heritage or local character. This means that the requirement to strengthen or remove a building would have greater importance than any other requirement to protect the building, unless the building qualified for an exemption on one of the proposed grounds (see Exemptions and time extensions, page 27). Any changes to the earthquake-prone building threshold would be made rarely, through regulation, and independently of any decision to change the standard required for new buildings. This is because building strengthening costs are very high and building owners should have certainty that, having complied with the mandatory national requirement, the compliance level would not be changed over the short-term. While changes to the threshold are expected to be rare, they will be necessary from time to time due to improvements in building technology or better understanding of natural hazards. For this reason, building owners may see benefits in strengthening to levels well above the threshold, to avoid potential future strengthening costs. The Royal Commission s view is the same as the conclusion in these proposals that, in general, the current earthquake-prone building definition should be retained. To quote its report: Overall, we do not consider that the experience of the Canterbury earthquakes should lead to the abandonment of the current one-third rule, which we have concluded should remain as the appropriate standard. (Section 7.4.1, Vol.4, Final Report) The Commission also recommends that, for unreinforced masonry buildings, the out-of-plane resistance of chimneys, parapets, ornaments and external walls to lateral forces shall be strengthened to be equal to or greater than 50 per cent Ultimate Limit State (that is, 50 per cent of the standard required for a new building). (Recommendation 84, Vol.4, Final Report). Further, it recommends that, after consulting with their communities, local authorities be able to require strengthening within shorter timeframes to achieve the minimum standard required by legislation for some or all of the buildings in its district (Recommendation 86, Vol.4, Final Report). It also recommends that, after consulting with their communities, local authorities be able to require higher strengthening standards for: some or all buildings in its district, or for high importance or high-occupancy buildings, or where public funding is to be contributed to building strengthening, or where the public safety hazard justifies a higher standard. (Recommendations 87 and 88, Vol.4, Final Report) 23 Building Seismic Performance - Consultation document - December 2012

27 Questions: 10. Does the current earthquake-prone building threshold (33 per cent of the requirement for new buildings) strike a reasonable balance between protecting people from harm and the costs of upgrading or removing the estimated 15-25,000 buildings likely to be below this line? 11. Should the requirement for earthquake-prone buildings to be strengthened or demolished take precedence over all other legal, regulatory and planning requirements, such as those designed to protect buildings of heritage or local character? 12. Should local authorities have the power to require higher levels of strengthening than the earthquake-prone building threshold, or strengthening within shorter timeframes than the legally defined period? 13. Should certain features of unreinforced masonry buildings, such as chimneys and parapets, be required to be strengthened to a higher level? Building Seismic Performance - Consultation document - December

28 Enforcing the mandatory national requirement Proposal 5: All buildings would be strengthened to be no longer earthquake-prone, or be demolished, within 15 years of the legislation taking effect (up to five years for local authorities to complete seismic capacity ratings, followed by 10 years for owners to strengthen or demolish buildings). Proposal 6: Strengthening would be carried out faster for certain buildings (eg, buildings on transport routes identified as critical in an emergency). Proposal 7: Owners of buildings assessed as earthquake-prone would have to submit a plan for strengthening or demolition within 12 months. Building owners would be required to act within a defined time period to strengthen or remove buildings, or parts of them, that are earthquake-prone. Sometimes this might mean securing a particular building feature, such as an unstable facade or awning, or it might mean strengthening the building s basic structure. In some cases, it will be most cost effective to demolish the building and redevelop the land. Owners of earthquake-prone buildings would need to develop a plan to strengthen or demolish these buildings within the required period, and to submit it for approval within 12 months of notification by the local authority. If they decide to strengthen, owners would need to obtain engineering advice (at their own expense) that would: identify and clearly indicate any critical structural or other weaknesses or features that, as a result of a moderate earthquake, would be likely to collapse and result in death or physical injury to people within, beside or outside the building (based on a methodology to be developed by MBIE, in consultation with relevant technical experts) advise on the remedial or mitigation measures needed to address any such weakness or features. Owners would be required to obtain local authority approval of plans to strengthen or demolish the building, with work to be completed within 10 years of the date the building is rated. The aim is that all buildings would be strengthened to be no longer earthquake-prone, or be demolished, within 15 years of the legislation taking effect (up to five years for local authorities to complete seismic capacity ratings, followed by 10 years for all earthquakeprone buildings to be strengthened or demolished). Currently, local authorities can set timeframes within which building owners must strengthen or demolish their buildings. It is proposed to set these timeframes nationally, allowing local authorities only limited discretion to extend them. 25 Building Seismic Performance - Consultation document - December 2012

29 It is proposed that local authorities could choose to require strengthening or demolition more quickly for strategically-important buildings, such as those: located on transport routes identified as critical in an emergency with important public, social and economic functions (such as schools and police stations) with post-earthquake recovery functions, such as civil defence centres and hospitals. The Royal Commission recommends timeframes be set nationally and that unreinforced masonry (URM) buildings be treated separately and strengthened more quickly than other earthquake-prone buildings. It recommends that all URM buildings be strengthened within seven years of the law change, and that other earthquakeprone buildings be strengthened within 15 years. (Recommendation 83, Vol.4, Final Report) Questions: 14. Is it reasonable and practicable for owners of earthquake-prone buildings to meet the following timeframes: 12 months to submit plans for either strengthening or demolishing a building? 10 years from the date of the seismic capacity rating to strengthen or demolish? 15. What additional powers would local authorities require to enforce the proposed requirements? 16. Should local authorities be able to require faster action on buildings of strategic importance, such as those: located on transport routes identified as critical in an emergency with important public, social and economic functions, such as schools and police stations with post-earthquake recovery functions, such as civil defence centres and hospitals? 17. Should all unreinforced masonry buildings require strengthening more quickly than other earthquake-prone buildings? Building Seismic Performance - Consultation document - December