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Earthquake-prone Dangerous Insanitary Buildings Policy

2006 – 2011 (June 2006)

1    Objective

2    Introduction

3    Background
      3.1 Earthquake-prone buildings
      3.2 Dangerous and insanitary buildings

4    Policy approach under the Building Act 2004
      4.1 Earthquake-prone buildings
      4.2 Dangerous and insanitary buildings

5    Identifying and prioritising earthquake-prone, dangerous and insanitary buildings
      5.1 Earthquake-prone buildings
      5.2 Dangerous and insanitary buildings

6    Interaction between the policy and related sections of the Building Act 2004
      6.1 Section 112: Alterations to existing buildings
      6.2 Section 115: Change of use
      6.3 Section 41: Building consent not required in certain cases

7    Recording of earthquake-prone, dangerous and insanitary buildings
      7.1 Earthquake-prone buildings
      7.2 Dangerous and insanitary buildings

8    Economic impact of the policy

9    Heritage buildings

1 OBJECTIVE
To address the council’s obligations under the Building Act 2004 in respect to the life safety of building owners, users and the public in and within close proximity to the district’s buildings by identifying danger that is appropriate to the degree of risk whilst having due regard to economic and heritage factors.

2 INTRODUCTION
Section 131 of the Building Act 2004 (“the Act”) requires territorial authorities to adopt a policy on earthquake-prone, dangerous and insanitary buildings by 31 May 2006. This reflects the government’s broader concern with the life safety of the public in buildings and, more particularly, the need to address life safety in the event of an earthquake. It is a requirement that the policy be developed in consultation with New Plymouth District Council ratepayers and stakeholders in accordance with section 83 of the Local Government Act 2002. The policy will be reviewed every five years.

Relevant definitions from the Act are stated in (a) (b) and (c) below.

(a) The definition of an earthquake-prone building is set out in section 122 of the Act:
     “(1) A building is earthquake-prone for the purposes of this Act if, having regard to its condition and
            to the ground on which it is built, and because of its construction, the building -
      (a) will have its ultimate capacity exceeded in a moderate earthquake (as defined in the regulations); and
      (b) would be likely to collapse causing-
           (i) injury or death to persons in the building or to persons on any other property; or
           (ii) damage to any other property.”

      (2) Subsection (1) does not apply to a building that is used wholly or mainly for residential purposes 
      unless the building–
      (a) comprises two or more storeys; and
      (b) contains three or more household units.”

With regard to what constitutes a “moderate” earthquake the Building (Specified Systems, Change the Use and Earthquake-Prone Buildings) Regulations 2005 defines it as “an earthquake that would generate shaking at the site of the building that is of the same duration as, but that is one-third as strong as, the earthquake shaking (determined by normal measures of acceleration, velocity and displacement) that would be used to design a new building at the site.”

The definition of an earthquake-prone building as stated in the Act covers more buildings and requires a higher level of structural performance of buildings than that required by the Building Act 1991.

(b) The definition of a dangerous building is set out in section 121(1) of the Act: “A building is dangerous for the purposes of this Act if,-
      (a) in the ordinary course of events (excluding the occurrence of an earthquake), the building is likely
      to cause-
           (i) injury or death (whether by collapse or otherwise) to any persons in it or to persons on other
           property;   or
          (ii) damage to other property; or
      (b) in the event of fire, injury or death to any person in the building or to persons on other property
      is likely because of fire hazard or the occupancy of the building.”

For the purposes of determining whether a building is dangerous, advice may be sought from members of the New Zealand Fire Service who have been notified to the council by the Fire Services National Commander as being competent to give advice.

(c) The definition of an insanitary building is set out in section 123 of the Act:
“A building is insanitary for the purposes of this Act if the building-
      (a) is offensive or likely to be injurious to health because-
           (i) of how it is situated or constructed; or
           (ii) it is on a state of disrepair; or
      (b) has insufficient or defective provisions against moisture penetration so as to cause dampness in
      the building or in any adjoining building; or
      (c) does not have a supply of potable water that is adequate for its intended use; or
      (d) does not have sanitary facilities that are adequate for its intended use.”Return to top


3 BACKGROUND
3.1 Earthquake-prone buildings
New Plymouth District is in a zone of low seismic activity. However, there are three known active fault lines within the New Plymouth district capable of producing significant earthquakes. These are the Inglewood and Norfolk faults which lie on either side of the Inglewood township and extend from southwest to northeast and the Turi fault which lies to the west of New Plymouth out to sea. The Turi fault is the fault most likely to affect the buildings in the North Taranaki region. However, a major earthquake outside of the region is the most likely event to produce sufficient ground movement to adversely affect the region’s buildings. Notwithstanding the above, the probability of a major earthquake affecting the New Plymouth district is low.

The buildings within the New Plymouth district comprise a range of types and ages reflecting steady development over the last 100 years from unreinforced masonry buildings to some modern multi-story steel and concrete buildings, the latter being particularly evident in New Plymouth city as opposed to the outlying townships. The refurbishment and redevelopment of some buildings within New Plymouth city for new uses has also seen some of the unreinforced masonry and brick buildings undergo strengthening. The level of earthquake strengthening achieved may have been insufficient and therefore still fall within the definition of an earthquake-prone building.

The council has not actively pursued a policy of identifying and strengthening earthquake prone buildings in the past but has relied upon the progressive upgrading, redevelopment or removal of at risk buildings through the change of use and alteration provisions in the Act.

Strengthening of buildings to the levels required under this policy will not "earthquake proof" buildings from damage. The level of strengthening required is to reduce the risk of the loss of life and damage to other property. The threshold level of one third of the earthquake shaking of the current loading standard means that a building is 20 – 25 times more likely to be damaged as a building designed to the current loading standard. At two thirds the level of earthquake shaking of the current loading standard a building is five times more likely to be damaged as a building designed to the current loading standard. Building owners and users need to be aware of these levels and decide whether those levels are acceptable for their investment or whether higher levels should be aimed for.

3.2 Dangerous and insanitary buildings
The council deals with isolated instances in the New Plymouth district of dangerous and insanitary buildings. For example, there are instances where buildings have been illegally converted from a commercial use into a residential use. This may create a danger for occupants in the future in terms of the inappropriate construction methods or materials used.

Unauthorised building work is an issue in the New Plymouth district, particularly in older houses where small alterations are made on an occasional basis over a long period of time. However, this unauthorised building work does not always contribute to a building being dangerous or insanitary.

Dangerous and insanitary buildings are brought to the council’s attention via complaints or concerns raised by building or other professionals or via general inspections. These are dealt with under the provisions of the Act and the Health Act 1956, sometimes in cooperation with other agencies. This approach has been effective in addressing the council’s statutory obligations.Return to top


4 POLICY APPROACH UNDER THE BUILDING ACT 2004
4.1 Earthquake-prone buildings
The council’s earthquake-prone building policy under the Act is an active approach that reflects the council’s determination to reduce earthquake risk over time in a way that is acceptable in social and economic terms to its ratepayers.

The council will:

• Undertake an initial desktop review of buildings that fall within the three categories identified in Section 5.1 of this policy to identify buildings that fall within the scope of potential earthquake-prone buildings under the Act. Council buildings will be included in this initial desktop review.
• Assess the performance of the potentially at risk building stock in an earthquake based on information obtained by using the New Zealand Society of Earthquake Engineers (NZSEE) Initial Evaluation Process in accordance with the Department of Building and Housing document “Assessment and Improvement of the Structural Performance of Buildings in Earthquake” (October 2005). Inspections will be carried out where necessary. This will be done at the council’s cost.
• Determine and compile from the assessment a list of buildings that are potentially earthquake-prone in terms of the Act.
• Advise owners of these buildings and the New Zealand Historic Places Trust of the results of the council’s assessment.
• Advise the owners of affected buildings to seek independent review of the council’s findings by obtaining a more detailed structural assessment of the building within a period of one year.
• Invite owners and the New Zealand Historic Places Trust where appropriate, within a limited timeframe, to discuss the findings and where risk is confirmed work with the council to define timelines for upgrading work to remove the danger that is appropriate to the degree of risk.
• Give written notice to the owners of earthquake-prone buildings once risk is confirmed, subject to the results of any discussions, to carry out work to reduce or remove the danger or demolish the building within specified timeframes. Where appropriate, work may be staged. The timeframe will reflect the degree of risk. If notice is given to strengthen an earthquake-prone building, the minimum level of strengthening required is one third of the current requirement for new buildings. Advise owners that they should consider strengthening beyond one third of the current requirement for new buildings where a change of use for the building is a future possibility.
• Allow owners a right of appeal as defined in the Act, which can include applying for a determination under section 177. The length of the appeal period will be six months.

4.2 Dangerous and insanitary buildings
The council’s dangerous and insanitary building policy under the Act is an ongoing approach that reflects the incident based approach that has worked well in the past and is acceptable in social and economic terms to its ratepayers. The council will respond to dangerous and insanitary building issues as required.

The council will:

• Investigate all complaints received from the public regarding potentially dangerous or insanitary buildings and investigate all instances where council officers are aware that a building may be dangerous or insanitary.
• Upon completing investigations, identify if the buildings are deemed to be dangerous or insanitary.
• Direct the owner(s) or occupier(s) of the dangerous or insanitary buildings to take action to reduce or remove the danger or the element contributing to the insanitary condition of the building.
• Liaise with relevant bodies such as the New Zealand Fire Service, Housing New Zealand, the Taranaki District Health Board and the New Zealand Historic Places Trust when appropriate.Return to top

5 IDENTIFYING AND PRIORITISING EARTHQUAKE-PRONE, DANGEROUS AND INSANITARY BUILDINGS
5.1 Earthquake-prone buildings
The council will limit the scope of the initial desktop review to buildings with special postdisaster functions; buildings that as a whole may contain people in crowds or contents of high value to the community or pose risks to people in crowds; and buildings with heritage value. Buildings will be considered in the initial desktop review if they fall into one of the categories listed below. They are based on importance levels in the Australia/New Zealand Standard 1170.0: 2002 Structural design actions, Part 0: General principles.

Category 1 Buildings that have special functions or whose failure poses catastrophic risk to a large area or a large number of people as defined in AS/NZS 1170.0: 2002, Importance Level 5. Buildings with special post-disaster functions as defined in AS/NZS 1170.0: 2002, Importance Level 4.

(Earthquake-prone buildings in Category 1 must be identified by the council by December 2008. The timeframe for strengthening or demolition for those buildings that are earthquake-prone will be a maximum of 15 years. The timeframe specified for each building will be based on the level of risk identified and will take effect from when written notice is given to carry out work to reduce or remove the danger or demolish the building.)

Category 2 Buildings that as a whole may contain people in crowds or contents of high value to the community or pose risks to people in crowds as defined in AS/NZS 1170.0: 2002, Importance Level 3.

(Earthquake-prone buildings in Category 2 must be identified by the council by December 2009. The timeframe for strengthening or demolition for those buildings that are earthquake-prone will be a maximum of 20 years. The timeframe specified for each building will be based on the level of risk identified and will take effect from when written notice is given to carry out work to reduce or remove the danger or demolish the building.)

Category 3 Buildings with a heritage classification of Category A under the New Plymouth District Plan that have not already been earthquake strengthened to withstand a moderate earthquake.

(Earthquake-prone buildings in Category 3 must be identified by the council by December 2010. The timeframe for strengthening or demolition for those buildings that are earthquake-prone will be a maximum of 30 years. The timeframe specified for each building will be based on the level of risk identified and will take effect from when written notice is given to carry out work to reduce or remove the danger or demolish the building. The New Zealand Historic Places Trust will be consulted regarding the timeframe specified for each building.)

Within the scope of the assessment criteria, the council will define earthquake-prone buildings as those that, when subject to moderate shaking, do not meet or exceed the criteria for ultimate limit state as defined in the loading and material standards for new buildings.

The council will use the NZSEE recommendations as its preferred basis for defining technical requirements and criteria. These recommendations are designed to be used in conjunction with AS/NZS 1170 Structural Design Actions Standard, NZS 3101 Concrete Structures Standard, NZS 3404 Steel Structures Standard and other materials standards.

Amongst the matters to be considered at the next review of this policy, will be buildings defined in AS/NZS 1170.0: 2002 as Importance Level 2.

5.2 Dangerous and insanitary buildings
The council will assess a dangerous building in accordance with section 121(1) of the Act and an insanitary building in accordance with section 123 of the Act. Section 123 states that a building is unsanitary if it does not have a supply of potable water that is adequate for its intended use. When considering what may constitute “a supply of potable water that is adequate for its intended use,” the council will take into account the difficulty of providing water treatment facilities in remote backcountry situations and allow for the provision of clean drinking water and the option of treatment by users before consumption.

The council will allocate priority to those buildings that are deemed to be immediately dangerous or insanitary. Immediate action will be required in these situations to reduce or remove the danger or the element contributing to the insanitary condition of the building. Buildings that are deemed to be dangerous or insanitary, but not immediately dangerous or insanitary, will be subject to the timeframes stated in section 121(1)(c) of the Act to reduce or remove the danger or the element contributing to the insanitary condition of the building. Investigations into earthquake-prone buildings could result in a building being declared dangerous and sections 128 and 129 of the Act may then apply. The council will notify the New Zealand Historic Places Trust of any building classified as a Category A heritage building under the New Plymouth District Plan that is deemed to be dangerous or insanitary.Return to top


6 INTERACTION BETWEEN THE POLICY AND RELATED SECTIONS OF THE BUILDING ACT 2004
6.1 Section 112: Alterations to existing buildings
Under this policy, whenever a building consent application is received for significant1 alteration of a building, an assessment under section 122 of the Act will be carried out. If the building is assessed as being earthquake-prone, the council will require evidence that the alteration will not impede the strengthening of the building and impose an appropriate timeline for remediation of the building. If the alteration impedes remediation, the council will not issue a building consent for the alterations until all or part of the required remediation is addressed within the area of the building being altered.

6.2 Section 115: Change of use
Section 115 of the Act overrides section 122 of the Act because it is more onerous, is mandatory under the Act and is not subject to this policy. Significant upgrading or alteration represents 30% or more of the improved value over any five year period.

6.3 Section 41: Building consent not required in certain cases
In cases where the council agrees there is extreme urgency to address a dangerous or insanitary building the council may waive the need for building consent to be obtained for the work required to remove the danger or fix the insanitary conditions immediately. A Certificate of Acceptance will need to be sought following the completion of the work.

7 RECORDING OF EARTHQUAKE-PRONE, DANGEROUS AND INSANITARY BUILDINGS
7.1 Earthquake-prone buildings
The council will keep a register of all earthquake-prone buildings noting any outstanding requirements for improvement or the improvements completed. In addition, the following information will be placed on the Land Information Memoranda (LIM) and Project Information Memoranda (PIM) for each earthquake-prone building:

• The address and legal description of the land and building.
• A statement that the building is on the council’s register of earthquake-prone buildings.
• The date by which strengthening or demolition is required (if known) and the work known to be completed. Most upgrading will be subject to building consent and noted accordingly.
• A statement that further details are available from the council.

The council will not require earthquake-prone buildings to have an identifying plaque. The council believes that having the information available at the council offices is sufficient notice at present.

In granting access to information concerning earthquake-prone buildings, the council will conform to the requirements of relevant legislation.

7.2 Dangerous and insanitary buildings
The council will hold all information regarding dangerous and insanitary buildings in the appropriate property files. If a building is deemed to be dangerous or insanitary at the time a LIM or PIM is applied for this will be documented in the LIM or PIM. Upgrading works completed other than those defined as maintenance will be subject to building consent and noted on a LIM. Information held by the council regarding previous works will
also be provided.

In granting access to information concerning dangerous and insanitary buildings the
council will conform to the requirements of relevant legislation.

Section 128 of the Act provides for the council to prevent access to, and place notice upon, a dangerous building which will act to notify the public of the danger.Return to top


8 ECONOMIC IMPACT OF THE POLICY
The true economic impact of the earthquake-prone, dangerous and insanitary policy will not be known until after the initial building evaluation phase has been completed and the extent of the required strengthening and demolition work has been identified. An economic impact assessment will be undertaken at this time.

9 HERITAGE BUILDINGS
While heritage buildings will be assessed in a manner consistent with assessments for other potentially earthquake-prone, dangerous and insanitary buildings, special efforts will be made to meet heritage objectives. It is important that in strengthening, upgrading and/or altering such buildings, heritage values and their protection are not lost sight of. Discussions will be held with owners and the New Zealand Historic Places Trust to identify a mutually acceptable way forward.

The council believes it is important that its heritage buildings are able to survive a moderate earthquake and that they are not dangerous or insanitary. However, the council does not wish to see the intrinsic heritage values of these buildings adversely affected by structural improvement or remedial measures. The council will therefore encourage the use of less invasive upgrading methods and will work with building owners and its technical advisors, including the New Zealand Historic Places Trust and heritage experts, in an effort to retain heritage values. In particularly important cases, public consultations will be included in the process. Where there are no viable alternatives to upgrading work that severely compromises heritage values, the council may agree to the best practical option that achieves a lesser standard of compliance by way of a formal waiver under the provisions of the Act.

The council will consider financial support for buildings deemed to be earthquake-prone, dangerous or insanitary through the council’s Heritage Protection Fund where the work will assist with the preservation of the building to a level greater than one-third. Several significant contributions have already been made from the fund towards the seismic upgrading of heritage buildings in the New Plymouth district. The adequacy of the fund to meet this demand will be monitored and, if there is a need for increased funding, this will be identified for consideration when budgets are reviewed.Return to top