Zealand Building Research Articles

A spectral assessment for instant preliminary evaluation of structures after seismic events

This article introduces a simple, efficient spectral-based approach for rapid preliminary seismic assessment of earthquake-affected structures. Performance is validated using data from three highly earthquake-affected structures in New Zealand, where visual inspection with subjective outcomes missed damage, resulting in inaccurate and delayed decisions with significant social and economic losses. The three structures considered include (1) the instrumented Bank of New Zealand (BNZ) building; (2) the un-instrumented Queensgate Mall (QM) Complex; and (3) the un-instrumented Canterbury Television (CTV) building. This study uses these cases to highlight the importance of structural health monitoring (SHM) instrumentation and reliable quantified post-earthquake assessment methods in earthquake-prone areas, where each damaging earthquake and subsequent further-damaging aftershocks demand continuous monitoring to continuously assess damage and life safety risk. The simple, low-cost spectral analyses in this study clearly show the existence of damage and deterioration not fully discovered with standard visual inspection methods. This outcome highlights the importance of sensor networks and SHM instrumentation so quantitative, post-event analysis can rapidly augment and target further, more subjective visual inspection results.

Structures incorporating damping devices: Are we correct in our design thinking?

The use of discrete damping devices in New Zealand buildings is increasing as designers seek to limit damage to both architectural and structural building elements in moderate earthquakes. The overall damping of the structure becomes a combination of inherent material damping, hysteretic damping from yielding of building elements at specific locations and damping from discrete devices. For over 60 years, engineers have used simplified analysis procedures (e.g., modal response spectrum analysis) to predict building response under seismic actions. The design of structures incorporating viscous dampers requires a paradigm shift in approach as the force each damper resists is a function of the relative velocity between its ends. Popular pseudo-static design methodologies promote the use of a viscous strut in the analysis model to represent them. However, it is incorrect to use elastic, mode-based analysis for a structure incorporating damping devices and relying on significant inelastic behaviour. This paper elucidates the complex mechanics of damper-structure interaction by reviewing some of the established classical, modal‑based, simplified analysis techniques used in seismic design. A series of numerical investigations demonstrate how these techniques are usually invalid for structures that incorporate viscous dampers because they violate the laws of physics. The reason why mode-based techniques are invalid is explored with reference to the imaginary components of the natural modes of vibration and the effect on them of significant inelasticity within the structure. The dynamic characteristics of viscous dampers challenge conventional design approaches such as displacement-based design. This paper establishes that nonlinear time-history analysis is the only meaningful way of predicting the dynamic response of a structure incorporating viscous dampers when significant inelastic behaviour of the structure is expected.

‘The window area shall be at least one-tenth of the area of the room’: The origins of a daylight (and ventilation) requirement in modern building codes

Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity provided only rules for window proportions but not for window area or size based on room dimensions. The paper demonstrates the evolution of this 21st century requirement follows a direct line to the English 1859 model ‘ Byelaws as to New Streets and Buildings’. Prior to that date, only two rules from 1842 (room volume based) and 1734 (height and volume based) have been found which gave a required window area based on room size. It is hypothesised that one of these led to the current rules. Although the current proportion rules may be appropriate, no empirical research-based origin has been identified.

A wintertime thermal analysis of New Zealand Homestar certified apartments for older people

ABSTRACT The New Zealand Building Code mandates maintaining habitable spaces and bathrooms in elderly homes at a minimum internal temperature of 16°C with adequate ventilation. This study assesses the thermal wintertime performance of 40 subsidized apartments designed for older residents within a 7-Homestar certified building in Auckland. The building performs well, falling below the 16°C threshold only 5 per cent of the time across all units. However, inconsistencies exist, particularly on the top floor (Level 3), which is colder than other levels. This reveals a potential flaw in the typology approach of green certifications, like Homestar, where certifying a single dwelling within an apartment building does not guarantee uniform thermal performance across all units.

Considering uncertainty in the collapse fragility of New Zealand buildings for risk‐targeted seismic design

AbstractThe risk‐targeted seismic design framework is used to set design intensities, based on achieving a target risk level (e.g., collapse or fatality risk) with respect to an assumed building collapse response. This paper assesses the distribution of fatality risk associated with the risk‐targeted design intensity, considering uncertainty in both the hazard and the variety of buildings that can satisfy the minimum design requirement. The randomness among buildings and their response is due to other design decisions (aleatory variability with respect to the design intensity) and can be represented by a distribution of fragility curves that quantify the collapse probabilities of as‐built, code‐conforming buildings. First, a single design intensity is calculated based on a “design fragility,” the mean hazard curve, and a risk target. The design fragility is taken as a conservative estimate from the distribution of collapse fragilities and the selected risk target approximates the risk associated with New Zealand's previous (non‐risk‐targeted) criteria for design intensities. Then the risk distribution is assessed, considering the aleatory variability in as‐built fragilities and the epistemic uncertainty in the new National Seismic Hazard Model. Accounting for variability in design decisions and uncertainty in the hazard model produces a risk distribution that more fully represents the potential risk associated with a given design intensity. This distribution can be compared to guidance on tolerable risk ranges, which suggest that risk can be variable among buildings but should fall within acceptable bounds. Sensitivity studies consider epistemic uncertainty in the assumed model for the distribution of as‐built fragilities. This inclusion of uncertainty to assess the risk distribution offers a powerful extension to the risk‐targeted framework. While this extension would not affect engineering practice (as the output is still a single design intensity), it allows building code developers to better understand and consider the risk implications associated with the selected design intensity.

Delivering Sustainable Housing through Material Choice

Increasing importance is being placed on sustainability worldwide to limit climate change’s effects. In New Zealand, a sizeable increase in demand for housing is driving a residential construction boom, with new dwelling consents increasing yearly for the last decade. The New Zealand Government’s commitment to sustainability has become legislation through the Climate Change Response (Zero Carbon) Amendment Act 2019. Therefore, the next stage is how the construction industry can limit and reduce its carbon emissions through one of the strategies, namely material choice. This study was intended to examine the influence of various building materials on climate change and to identify how more sustainable home construction and design in New Zealand may contribute to the government’s 2050 emissions reduction targets. A life-cycle assessment (LCA) was used in this study to investigate the global warming potential (GWP) produced by five case study houses and various material options for building envelope components. The study focused on the environmental impact of materials with high usage in industry and potential new materials that have shown an ability to conform to the New Zealand Building Code standards. It was found that case study House 1 (with timber flooring founded on senton piles with concrete footings, a timber frame, plywood wall cladding, and metal roof cladding) and House 2 (with a concrete waffle slab, a light steel frame, masonry wall cladding, and metal roof cladding) had the lowest GWP emissions compared to the other case study houses, with 631.13 and 633.16 kg CO2eq/m2, respectively. However, it should be noted that all the case study houses were not similar in size and design. In addition, the study investigated the different building envelope material options for the foundation, wall cladding, framing, and roof cladding. The study found that some new materials or materials that are not common in New Zealand could be used as an option for the housing envelope by having lower carbon emissions, such as 3D-printed concrete blocks compared with brick and concrete masonry for wall cladding systems.

Comparative Evaluation on the Response of New Zealand Buildings to Natural Disasters

Comparative Evaluation on the Response of New Zealand Buildings to Natural Disasters

Study of the Photographer as a Study: Looking Inside Duncan Winder's Home (sometime between c1962 and 1965)

In recent years there has been a small increase in research addressing the architectural photography of Duncan Winder. While this scholarship adds to critical appreciation of his skill and productivity as a recorder of New Zealand buildings, of his personal life we remain largely ignorant. To know an artist's life well does not guarantee a transparent view into their creative mind, but in the case of Winder we are so bereft of insight into his private life that the only way we have to explore him biographically is through his photographs. Overwhelmingly, Winder's archived oeuvre demonstrates a photographer determined to keep his own image firmly behind the lens. Foreground shadows and, on occasion, a blurred reflection, signal rare glimpses of the photographer at work. But otherwise, his common technique of bringing a hidden character to the camera suggests a determined effort by Winder to not only remain outside the view of the lens, but apart from the entirety of the scene being recorded. Against this pattern, this paper identifies seven images drawn from the Winder archive that present as being of a common domestic interior dated to the 1960s. Contrary to the proliferation of architect-designed rooms that dominate Winder's archive, these photographs show a modest home whose domestic character might be best categorised as "bach-like." Added to this, the composition of each photograph is unusually casual for Winder's work, and they read more as impulsive snap-shots than considered views. When content details are correlated against archival information it can be faithfully concluded that this interior is the home of Duncan Winder. The remainder of the paper interprets one of these images – "House interior, study" - as a knowing self-portrait by the photographer, and the visual scene is interrogated for evidence of Winder's inner world.

NZSS 1900 Model Building By-law: a planned evolution

Twenty-five years after its publication, NZSS 95:1935 "Model Building By-law" was starting to show its age. The 1961 City Engineers conference requested it be reorganised to put general requirements first and design requirements later. The NZ Standards Institute's (NZSI) Bylaw Sectional Committee thought this a good idea, although to avoid confusion changed the designation of the new series to NZSS 1900. From late 1963 to mid-1964, NZSS 95 was reissued as NZSS 1900. The 14 parts of NZSS 95 became 11 chapters of NZSS 1900, initially by reprinting with new covers. Over the next 20 years the chapters were modified, revised, split, or amalgamated.On 1 April 1966 NZSI became the Standards Association of New Zealand (SANZ), and 'New Zealand Standard Specifications" (NZSS) became "New Zealand Standards" (NZS). By late 1966 the revision and publication of NZS 1900 was nearly complete. For the future a five yearly review cycle was planned. However, storm clouds were ahead. NZS 1900 had a mixture of: legal requirements; design and construction requirements; quantitative requirements; and codes of practice. The resultant documents were considered to be hard to: use; inspect on site; and revise. In late 1969 the Standards Council was looking forward to a revision separating requirements (fixed, unchanging and rarely alternative) from solutions (changing as technology develops, often with alternatives). The "means of compliance" could be provided for the majority of users, while other solutions were available as desired or required. This set the scene for the Building Act 1991 and New Zealand Building Code.The paper reviews the development of NZS 1900, exploring the similarities and differences to NZSS 95. As an example of the process, the evolution of the requirement for windows for ventilation will be examined.

Comparing two AI methods for predicting the future trend of New Zealand building projects: Decision Tree and Artificial Neural Network

The rise of Artificial Intelligence and Machine Learning in many aspects of construction management has helped this industry to further improve the management, design, and planning of construction projects. This trend happens in many construction sectors, including in New Zealand. Whilst relatively smaller compared to construction sectors in other OECD countries, the construction sector in New Zealand carries a similar degree of complexity and with its own unique characteristics. Various studies showed that AI and ML can be used for analysis of construction data to generate further insights and to predict future trends in construction sectors. However, the AI approaches have their own set of challenges such as complexity, high cost of training, failure, and change. Aiming to better understand the trends and requirements of New Zealand building projects, this study started with a review of the existing AI methods that are currently being applied. Accordingly, compare and evaluate the accuracy of two AI prediction methods. The two methods of Decision Tree and Artificial Neural Network are selected based on their predictive power and accuracy. These methods are conducted by using available historical building data which is available on StatsNZ website. A portion of the data is used for testing and evaluation purposes, and the rest of the data is used for training the AI methods. It was identified that the Decision Tree method did not show suitable accuracy for prediction building consents issued data. In comparison, Artificial Neural Network shows a reasonable range with 95% of confidence level. Therefore, this method is applied for building consents issued in New Zealand.

Development of a framework for quality assurance of off-site manufactured building components: A case study of the New Zealand housing sector

A shortage of housing is a prominent issue across the globe. Traditional on-site construction methods seem too inefficient to meet the increasing housing demand. As a solution, many countries, including the United States, Germany, Singapore, Japan, Hong Kong and Australia, have introduced off-site manufacturing methods to increase the housing supply. Different from the traditional way of on-site construction, off-site manufacturing is a technique that involves manufacturing building components in a controlled environment. Despite strong government support and industry attempts to increase off-site manufacturing, the current building consenting and inspection processes in New Zealand have significant quality-related issues. Therefore, this study aimed to identify the gaps in current quality assurance processes used in off-site manufacturing and recommend a framework in order to gain credibility and the acceptance of the construction market. The study collected qualitative data from industry experts (e.g., developers, architects, engineers, project managers, quantity surveyors, head contractors and council officers) who had significant experience in current quality assurance regimes in New Zealand prefabrication construction. The key themes for designing the proposed framework were generated using content analysis of the primary data collected from semi-structured interviews with industry experts. The study has found that standardisation in off-shore products regarding the New Zealand Building Code remains the biggest challenge in the consenting process. Quality assurance and inspection test plans are the developer’s responsibility and are typically provided by third-party inspectors. In this post-Covid-19 world-building, consent authorities rely heavily on third-party inspection companies that apply more rigorous auditing. Essentially, the most important parts of quality assurance are to have an experienced team and to adopt a holistic approach by engaging stakeholders early in the design stage. The stakeholders should consider recommendations for mandatory after-service insurance to ensure end-customer interests are protected. The findings of this study can contribute to the early engagement of different stakeholders to ensure overseas manufacturing of building components meets New Zealand quality standards. It is expected that the new quality assurance framework would help to promote off-site manufacturing for the New Zealand housing sector.

A REVIEW OF A SUBORDINATE FIRE SAFETY LAW: IS IT LEGAL?

In Australia and the UK, problems within the fire safety market have resulted in both the Executive and private sector carrying out their own investigations; by the Executive: Shergold Weir Report (Australia), and the Hackitt Report (UK); and, by the private sector: the Warren Centre’s (Australia) fire review program. Because of the findings, some fire safety laws have been changed, by the Executive. New Zealand’s fire safety laws, particularly those below that of the Building Act (i.e., subordinate laws), have also undergone significant change since 2012, again, made by the Executive and have not gone without debate. Some changes, such as compulsory design procedures in a verification method, have caused notable discontent. In response, the New Zealand government funded fire review programs to investigate these issues. This paper looks at how the Judiciary has the power to rule over any law changes made by the Executive under judicial review circumstances in Australia, the UK, and New Zealand (“Westminster countries”), using the compulsory design procedure within a verification method as an example. When analyzing this change against the statutory Acts and Westminster judicial doctrines that the Judiciary must rule within, it is concluded that this design procedure is inconsistent with the New Zealand Building Act and therefore illegal, that there are strong grounds for judicial review, and using judicial review principles to analyze construction laws during the bidding, design, and construction process is recommended when working in Westminster countries.

Stakeholders’ perspectives on BIM and LCA for green buildings

There is growing concern about the environmental impacts of buildings on climate change. In this regard, the concept of integrating building technologies and environmental assessment methods, namely Building Information Modelling (BIM) and Life Cycle Assessment (LCA), has arisen as an innovative approach to improve building environmental assessment at the design phase. Recent studies made attempts to develop theoretical frameworks for BIM and LCA integration focusing on the technical aspects and the challenges of this integration. However, the stakeholders' perspectives on this integration of BIM and LCA for building environmental assessment have been overlooked. Therefore, there is a pressing need to understand the stakeholders' perspectives on BIM and LCA and their value for improving green building design and assessment. This study contributes to the existing knowledge on the potential implementation of an integrated BIM-LCA framework for building environmental assessment. To this end, this study investigates (1) the current applications of BIM and LCA in green buildings from the stakeholders' perspectives and (2) the stakeholders' level of awareness and agreement on the significance of BIM and LCA for green building design and assessment. In order to achieve this goal, a national survey was conducted among multiple stakeholders in the New Zealand building industry. The results indicate that BIM and LCA applications for green buildings are still immature. A statistically significant correlation is observed between the importance of BIM and LCA applications for green buildings. The stakeholders perceive BIM and LCA potentials and their integration positively. However, the current practices and applications of BIM and LCA do not align with the stakeholders’ perceptions. Massive efforts are still required for a wide implementation of BIM and LCA and their potential integration for green buildings.

Standing Tall: the evolution of habitable room height limits in New Zealand building controls

Although it is often thought that the 3 February 1931 Napier earthquake led to the first New Zealand building codes, they have a far longer history. Often developed by the local town, city or borough engineer, these codes or by-laws covered a wide range of topics, not just structural safety. Two surveys of local government building bylaws undertaken to support the development of national building controls, have created digests of details from a number of these codes. The 1924 survey of 37 municipalities supported the development of the first national code for timber buildings, while the 1938 survey of 84 municipalities was used to develop NZSS 95 Model Building By-law during the 1930s and early 1940s. The digests provide an opportunity to explore the 1930s development of building by-laws by geographical and topic coverage, as well as the impact on building controls since that time.These local building bylaws often included requirements that affected the interior architecture of buildings, such as the requirement for minimum dwelling or bedroom room heights. In 1924 these minima ranged from 8 ft to 10 ft (2.4 m to 3.0 m) for either a dwelling or an attic room. However, by 1938 while the height range for dwelling rooms was unchanged for attic rooms the range was reduced by 1 foot (0.3 m) to 7 ft to 9 ft (2.1 to 2.9 m). Although the 1992 New Zealand Building Code does not specify minimum habitable room heights, the House Improvement Regulations 1947 are still in force. These initially set the habitable room height requirement to 2.1 m, increasing in 1975 to 2.4 m.The paper explores the development of minimum dwelling height requirements in New Zealand using these two surveys with analysis of Wellington and Dunedin City Councils from the 1870s to the 1930s. These requirements will be compared to UK codes, exploring both the international evolution of room height requirements and the relationship to New Zealand.

Hybrid posttensioned rocking (HPR) frame buildings: Low-damage vs low-loss paradox

The 2010-11 Canterbury Earthquake Sequence inflicted seismic losses worth more than $40B, which is about 25% of the GDP of New Zealand (as per 2011 data). More than 80% of these losses were insured, which comprised of more than $10B covered by the Earthquake Commission (a New Zealand crown entity providing insurance to residential property owners) and more than $22B (comprising of roughly equal split between domestic and commercial claims) by private insurers [1]. The scale of financial impact has been perceived to be disproportionately large given the building regulatory regime in New Zealand is relatively stringent and the earthquakes and aftershocks were of moderate magnitude. As it is well known that some of the major faults spread in the Wellington region and the subduction boundary passing through the centre of New Zealand can generate much bigger earthquakes (upwards of magnitude 8), people are left pondering whether New Zealand is able to cope with the financial impact of larger earthquakes. This fearful realisation gradually led to people being dissatisfied with merely life-safe buildings and demanding more resilient buildings that meet the objectives of performance based design; i.e. suffer less damage, incur less loss, and can remain functional after earthquakes.
 In light of the extensive building damage resulting in high financial loss in recent earthquakes, practicing engineers and researchers in New Zealand have been advocating for revising the current design approach to improve performance of new structures and infrastructure in future earthquakes [2-5]. As a result, large proportion of buildings constructed in the last decade (including those built to replace earthquake-damaged buildings) have shied away from the traditional damage-friendly ductile structural systems and instead adopted one of the new and emerging structural systems claimed to be “low-damage”. In many cases, the adopted structural systems are not covered by existing design standards and are approved as alternate solutions through expert peer review. The “low-damage” attribute of most structural systems has been validated by component (or sub-assembly) level experimental tests, but their interactions with other building components and implications of their use in buildings have not been rigorously scrutinised. Hence, the rushed adoption of some of these systems in buildings can surprise the engineering community in future earthquakes with mismatch between the expected and real performances of the buildings; akin to what New Zealand engineering fraternity is currently going through due to realisation of poor seismic performance of precast hollow-core flooring system that has been widely used in New Zealand buildings without rigorous scrutiny.
 One such “low-damage” structural system is precast post-tensioned rocking frames with supplemental energy dissipaters. This paper summarises the development of this structural system, critically reviews the literature reporting the seismic performance of this system, and qualitatively evaluates system-level implications of its use in buildings. This paper is intended to better inform engineers of the likely seismic performance of buildings with this structural system so that they can optimise its benefits by giving due consideration to its effect on other building components.

Hygrothermal Characteristics of Cold Roof Cavities in New Zealand

The New Zealand Building Code contains minimum durability requirements for components. For roof structures the requirement is 50 years if the component is structural or 15 years if it is not. Metal roof claddings are very common in New Zealand, and roof spaces are typically not deliberately ventilated. Recently, a number of roofs are failing to meet their durability requirement, and the lack of deliberate ventilation is a contributory factor in some cases. In this paper, we consider roof failures and analyse them using the hygrothermal simulation software WUFI® 2D (version 4.1). Using the National Research Council of Canada’s Guideline on Design for Durability of Building Envelopes, we evaluate to what extent the guideline can be used for such more complex models. Experimental data from a residential dwelling where excessive roof moisture issues were discovered shortly after occupancy are presented. A novel remedial solution using daytime-only ventilation to the roof cavity was trialled, and the data were used to benchmark a two-dimensional numerical simulation of the roof space using WUFI® 2D. A larger hygrothermal data set for 71 dwellings is presented together with relevant climatic conditions. The study works towards evidence-based building code changes for roof ventilation and is an example of using the guideline document for more complicated building envelope assemblies.

An evidence-based framework validation for building code improvement in New Zealand

PurposeNew Zealand building code may be serving its purpose to an extent, there is still a need to develop a framework to improve the use and application of building code for better building performance and services. This study aims to validate the identified parameters in the developed framework to improve building code practice in New Zealand.Design/methodology/approachSubject matter experts interview was conducted with key stakeholders that use building code, standards and other associated compliance documents.FindingsThe findings from this study establish the importance of improving the building code, and the efficacy of validated framework helps to identify the areas with the most pressing needs within the building regulatory system. All the subject matter experts unanimously agreed on educating and training the building code users. Besides, the validated framework will enable the policy decision-makers in the building regulatory system to promote the use of building code and the utilisation of its potentials in reducing disaster while increasing the built environment resilience. The study concludes that the designed framework will create more robust strategy implementations to enhance innovative solutions embedded in performance-based building code.Originality/valueThis study originality centres on the practical application of an evidence-based framework for performance-based building code, standards and other related compliance documents.

Creating a case for innovation acceleration in the New Zealand building industry

Purpose This study aims to examine how innovation can be accelerated within the New Zealand (NZ) building industry to improve the productivity and efficiency of the industry. Design/methodology/approach The study adopted a mixed philosophical approach combining interpretivism and post-positivism. Data for the study were obtained through a focus group of 50 practitioners that were selected using a stratified sampling procedure. All focus group data were audio-recorded, notes of the discussions were taken and then transcribed, de-identified and managed using NVivo software. Data analysis was undertaken using thematic analysis and inductive reasoning consistent with interpretative phenomenological analysis. Findings The study findings revealed that the industry could benefit from the adoption of new and emerging technologies to improve its performance, especially its productivity and efficiency. Key drivers for the adoption of innovative practices included the adaptation of “local best practices” from case studies that would consist of stories of successful innovations that could foster confidence in future innovation. It was also identified that Government and industry should nurture innovation through collaborative contracts, policies and regulations. Further, it was highlighted that a culture of innovation needed to be developed to help nurture competencies and capability within the industry workforce. Research limitations/implications This study provides an in-depth examination of the need for innovation from the point of view of building industry practitioners. This study provides a useful starting-off point for further research and for the creation of policies that could help to support and accelerate innovation within the NZ building industry. Practical implications NZ’s building industry productivity and efficiency have been sub-optimal relative to other industries. But using evidence from the experiences and knowledge of industry practitioners, strategies can be developed to accelerate innovation within the NZ building industry that could help reverse industry performance. Further, the research findings can help inform government policies to develop support mechanisms that could encourage innovation in the industry in NZ. In addition, it is anticipated that the findings will provide a useful set of guidance for other countries that have similar market and physical constraints as those encountered by NZ. Originality/value There is a dearth of empirical studies on innovation in the NZ building industry which the current study contributes to. By sharing industry practitioners’ experiences and knowledge of innovation, the paper seeks to counteract more technocratic and technological optimist accounts of innovation within the building industry. Further, the paper provides insights into how the NZ building industry can transform its performance through innovation.

Building code amendment and building resilience: perspective of building code users in New Zealand

PurposeThe process followed in amending building code creates problems for code users within the building industry. These problems include the need and frequency of changes made to building code, access to updated documents, method of communication, amendment interval and amendment pathway. This study aims to explore the viewpoints of building code users regarding building code amendments in New Zealand.Design/methodology/approachUsing a closed-ended questionnaire survey, this paper examined the New Zealand building code amendments by evaluating the views of experienced and relevant stakeholders within the research area.FindingsA high proportion (50.90%) of the survey participants agreed to a three-years building code amendment cycle, as against the current biannual Amendment practiced in New Zealand. Findings from the study affirmed the necessity for building code amendment and the support for free amended building code documents to the public and other building standards. The study concludes with strong support to the use of intensive research and learning gained from disasters in building code amendment in New Zealand. Implementing the code users opinions encourages disaster resilience through effective application of the building code requirements in design and construction.Originality/valueThe contribution from this study offered a unique insight into the perspectives of building code users on building code amendment in New Zealand and ways of incorporating the findings in the building code later updates to improve disaster resilience in the built environment.

Contractor-Delay Control in Building Projects: Escalation of Strategy from Primary Proactive to Secondary Reactive

The building sector in New Zealand is booming and currently very active, with a range of residential and commercial buildings being built in large cities. However, where there are major investments, problems, malfunctions, and errors become extremely costly and time consuming with significant implications on the success of projects. The current study focuses on causes of delay in building projects; in addition, the study sets out to investigate causes associated with or triggered by contractors within the construction phase. The emphasis is on causes that are more likely to create problems, conflicts, and disputes. A total of 14 types of delays were initially investigated through a review of relevant and high-impact sources. Accordingly, the causes of these delays were further investigated and verified via New Zealand building and construction experts. The discussions and analysis were extended beyond the causes and into response strategies and control of emerging issues and problems. The study suggests an action plan and spectrum of actions and strategies to avoid or mitigate the impact of the causes. This action plan is classified into proactive and reactive measures.