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Codewords Issue 79

27 July 2017

In this issue:

We’re over the halfway mark for the year – and kicked off 1 July with three big ticket items for the industry:

  • The Building (Accreditation of Building Consent Authorities) Regulations 2006 were updated to include the 2017 amendment regulations. The BCA Accreditation section of the website has been updated to reflect this change. Detailed regulatory guidance has further information on each regulation, as well as Word checklists to help you meet your BCA requirements.
  • The new system for managing earthquake-prone buildings came into effect. This changes the way earthquake-prone buildings are identified, assessed and managed. This edition includes an update on what’s coming up in this area.
  • The Building Code turned 25. This one might make a few of us feel our age!

Generally I avoid talking about the weather – but the last few weeks have really highlighted the importance of keeping warm in winter! So it’s timely that we have a piece in this edition on ensuring that solid fuel heaters are installed and maintained safely – with the appropriate consents.

As part of the education and information programme to remind homeowners of their rights and responsibilities, MBIE has produced three foreign-language factsheets to help homeowners who are building or renovating. The factsheets are available in Hindi, Korean and Simplified Chinese and highlight the value of having a written contract and the importance of asking contractors for a disclosure statement and checklist.

As you’ll be aware, Building System Performance is in the process of a restructure. The aim is to ensure the branch is focused on the right activities and has the right supporting structure. Planned go-live for the restructure is in September so watch this space for more news.

Keep warm and stay safe on-site – and on the roads.

Chris

Chris Kane

Chris Kane

Manager, Sector Trends and Innovation

Code and technical changes

Solid fuel heater modifications need a building consent

It’s a good time of year to think about solid fuel heaters (eg wood burners or pellet fires) and ensure these appliances are installed and maintained in a safe manner – with the appropriate consents.

There are safety concerns associated with any appliance that contains fire. Building owners planning to install, replace or modify a solid fuel heater are required to obtain a building consent from their building consent authority under section 40 of the Building Act 2004.

There are a few exemptions to this. Schedule 1 of the Building Act permits building work that involves general repair, maintenance and replacement (if comparable materials are used) to be carried out without a building consent. For example, this might include replacing the flue, firebricks, seals or glass. Schedule 1 does not include moving the appliance or modifying the appliance (such as installing a new part or device, or altering the make-up of the appliance) to make it burn hotter or more efficiently – this work will require a building consent.

Modifying an existing solid fuel heater has the potential to affect the building’s compliance with the Building Code, and in the worst case make the heater dangerous. For example, the modified appliance could increase the temperature of adjacent combustible wall surfaces, which are required by the Building Code to not exceed 90 degrees.

All building work must comply with the Building Code, regardless of whether it needs a building consent.

Councils sometimes have additional planning restrictions in place about the type of fireplace that can be installed, and how it must be operated. The aim is to reduce negative effects on the occupants’ health or to prevent nuisance to neighbours. Your council will be able to advise you about any requirements.

New wood burners must also comply with the National Environmental Standards for Air Quality under the Resource Management Act 1991.

Authorised wood burners on the Ministry for the Environment website has information on how you can find out if an appliance is an approved model.

A few things to remember:

  • Get a building consent before installing or modifying a solid fuel heater.
  • If you are in doubt about whether building consent is required, check with your building consent authority. It is unlawful to carry out certain building work except in accordance with a building consent.
  • Follow the manufacturer’s recommendations for these appliances carefully – including any requirements for maintenance (such as cleaning the flue). Deviations from these recommendations may void any warranty as well as affect the performance and safety of the appliance and the building. It could also put your insurance coverage at risk.

Applying for building consent has further information.

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Consultation opens on Fire Safety Residential Community Housing proposal

MBIE is seeking your feedback on a proposed Design Guide for Fire Safety: Residential Community Housing. The consultation will run from 17 July 2017 to 11 September 2017.

The proposed Design Guide was developed following stakeholder feedback on the 2012 edition of revised Acceptable Solution C/AS1-7. Stakeholders noted that the current Acceptable Solution C/AS3 provided a ‘one size fits all’ approach, without considering the differing levels of care and mobility of occupants in residential community housing and their ability to self-evacuate in the event of a fire. The stakeholders considered this would increase costs and reduce amenity value.

A categorisation method has been developed in the proposed Design Guide that takes into account the differing needs of occupants and each category has a gradual increase in the level of fire safety.

MBIE has received input from Community Housing Aotearoa, NZ Disability Support Network, Disabled Persons Assembly, Housing NZ, Ministry of Heath, Accessible Properties, the New Zealand Fire Service and building control officials to develop this proposed Design Guide.

View the proposals and make a submission on the MBIE Corporate website

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New earthquake-prone buildings system takes effect

A new national system for managing earthquake-prone buildings came into effect on 1 July 2017.

Over the next couple of months MBIE will be adding more information and developing additional guidance, information sheets and training material – so keep checking the site.

Managing earthquake-prone buildings has information and guidance on the new system.

Guidance on Priority Buildings is now available online. The concept of ‘priority buildings’ was introduced in the new system. They are certain types of buildings in high and medium seismic risk areas that are considered to present a higher risk because of their construction, type, use or location. They need to be identified and remediated within half the time allowed for other buildings in the same seismic risk areas.

Priority Buildings has further information.

EPB Register

Over the next few months territorial authorities who issued EPB notices for buildings under the old system will start to add these buildings to the EPB Register. This means that information about these buildings will become available in this new register over time.

Check out the EPB Register

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Online tutorial for passive rockfall protection structures

In June 2017, an online tutorial providing instruction on the design of passive rockfall protection structures became available on the Engineering New Zealand website.

Rockfall structures such as fences and embankments act to reduce the effects of falling rock on people and/or infrastructure.

The tutorial is available free to all geotechnical professionals and is part of a wider geotechnical education programme. Continuing Professional Development points can be gained from watching the presentation and undertaking a quiz.

The tutorial is based on the rockfall guidance document MBIE developed in collaboration with the New Zealand Geotechnical Society and the New Zealand Transport Agency. It is part of the broader guidance on geotechnical engineering, developed by MBIE, about issues arising from the Canterbury earthquake.

You can access the online tutorial on the Engineering New Zealand website

Rockfall: Design considerations for passive protection structures has the guidance.

Geotechnical education has further information on the geotechnical education programme.

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LBP knowledge link

LBP Registrar update (Codewords 79)

In this issue you’ll see the second article in our exempt building work series and an article on sound insulation.

Paul HobbsPaul Hobbs

In our previous article in the exempt building work series, we discussed simple and easy to measure situations where you can carry out building work without a building consent.

In this issue, we’ve followed up with more complex situations that don’t require a building consent.

Sound insulation is becoming increasingly important as construction density increases in residential areas. In this article we explain some of the things you should consider in this article if you’re going to be detailing or installing sound insulation.

We have also included an article detailing learnings from recent LBP complaint decisions by the Building Practitioners Board. Two LBPs have been named in the article due to the seriousness of the complaints.

Our article on Immigration New Zealand’s VisaView tool is well worth reading if you are considering employing migrants – before you hire anyone you need to make sure they can legally work here.

Finally, our first LBP Practice Note is nearing completion. It focuses on supervision, the dos and don’ts and what you need to know. We will be publishing it soon and it will be a key read for all LBPs – keep an eye out for it!

As we head into winter, make sure you stay safe. Frosts in the morning and wet days can make working at heights more dangerous so you need to be vigilant.

Until next time,

Paul Hobbs
Registrar Building Practitioner Licensing

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Know your stuff: Exempt Building Work, Part 2

Part 1 of this series covered off the basics of exempt building work and some of the easy to measure exemptions. Part 2 will go into a few of the more complex exemptions.

As a brief recap, all building work requires a building consent, except for work exempted under Schedule 1 of the Building Act 2004. Schedule 1 lists the building work that is exempt from needing a building consent.

Building work that does not require a building consent is helpful and practical Schedule 1 guidance.

Don’t forget to check if you need a building consent. This will help you avoid fines from councils or penalties from the Building Practitioners Board. You can check by reading the Schedule 1 guidance and contacting your local building consent authority.

Exemption 8 – Windows and exterior doorways in existing dwellings and outbuildings

All work in connection with a window (including a roof window) or exterior doorway in an existing dwelling or outbuilding of not more than two storeys in height is exempt work.
However, if you are replacing a window or doorway, that item must not have failed its durability test under Clause B2 of the Building Code. Based on the current Building Code, this means that the existing item that is being replaced must have satisfied the 15-year durability requirement.

You will need to get a building consent if the item has rotted and needs replacing within 15 years of installation, or if the building work modifies a specified system (such as installing a roof window and repositioning a sprinkler head).

This exemption covers structural and/or weathertightness work as long as the purpose of that work is to install the window or exterior doorway.

Exemption 11 – Internal walls and doorways in existing building

Changing an internal wall or doorway is exempt building work unless the wall is:

  • load bearing
  • a bracing element
  • a firewall (ie a barrier designed to limit the spread of fire, heat and structural collapse)
  • part of a specified system (such as electromagnetic or automatic doors)
  • made of ‘units’ of materials stacked or bonded together with mortar (like bricks or blocks).

Exemption 12 – Internal linings and finishes in existing dwelling

You can replace any interior linings without using comparable materials in an existing dwelling without needing a building consent.

Interior linings could be part of bracing or fire resistant elements, so we suggest investigating and installing the appropriate type of replacement lining.

Exemption 13 – Thermal insulation

You don’t need a building consent to install thermal insulation in an existing building unless you are installing it in an exterior wall or an interior firewall.

Installing insulation in ceilings, floors and interior walls that are not firewalls are examples of exempt work.

Under the Residential Tenancy Act, ceiling and underfloor insulation will be compulsory in all rental homes from 1 July 2019.

Insulation on the Tenancy website has more information on this requirement.

Exemption 14 – Penetrations

Penetrations can be made that are 300mm or less in diameter can be made through both internal and external building components without a building consent for:

  • detached dwellings of any height and dwellings within a building that is not more than three storeys high
  • outbuildings that are detached and not more than three storeys high
  • all other buildings as long as doing so does not modify or affect
    • the primary structure
    • any specified system.

The exemption includes any associated building work like weatherproofing or fireproofing.

For other scenarios (such as a commercial building), creating a penetration – not exceeding – 300mm in diameter is still exempt building work if the work does not affect the primary structure or a specified system (such as a fire suppression system).

Exemption 35 – Alteration to existing sanitary plumbing (excluding water heaters)

Alterations to sanitary plumbing fixtures (baths, showers, basins, etc) are exempt from building consent requirements as long as you are not increasing the number of fixtures in the building and the alteration does not affect a specified system (such as fire sprinklers).

This work must be done by an authorised person (see page 79 of MBIE's guidance). It also excludes work for water heaters (although this work may be covered by other exemptions).

Next time…

The next article in our Exempt Building Work series will cover off the trickiest exemptions you’re likely to encounter. Stay tuned.

Quiz

1) If you go to quote for a client to replace a window in their two-storey home, would you need to price in the cost of a building consent?

a. Yes, you need a building consent because the dwelling is two storeys
b. No, as long as it wasn’t installed less than 15 years ago and hasn’t leaked or rotted

2) Is work to remove my exterior wall exempt if I am removing it to extend my lounge over my deck?

a. You need to get a consent because it’s an addition and there are no Schedule 1 exemptions for external walls.
b. Yes, as long as it is not a firewall
c. It doesn’t require a consent because it’s a deck

3) I want to change my tongue and groove kitchen floor to plywood with a floating floor over it. I also want to install insulation beneath the floor. Can I do this all without a building consent?

a. Only if it the floor is not a bracing element
b. No, you can’t start without a building consent
c. Yes, it is exempt work
d. You can’t install the insulation without a building consent

4) I have been asked to cut a 150mm vent for a heat pump through a brick veneer wall. Can I do this without a building consent?

a. You need a brick and blocklaying LBP licence for that, but not a building consent
b. You need a building consent and a brick and blocklaying LBP licence
c. You don’t need a building consent for penetrations, but you need to be a registered electrical worker to do that work.

5) I am a roofing LBP and I want to cut a roof vent into an existing roof. How big can it be before I need a building consent?

a. You’re licensed as a roofer – you don’t need any building consents
b. 300mm in diameter
c. 100mm in diameter
d. 500mm in diameter

Check your answers

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Reducing noise transmission

With higher density housing becoming more widespread, designers and builders need to be up to speed with how wall assemblies can limit airborne and impact sound transmission between joined buildings.

Article is relevant to LBP licence classes: Design, Site, Carpentry

As New Zealand’s population grows, our district plans and long-term planning rules change to ensure we build enough homes for our residents. In many areas of the country, these changes have resulted in a move away from the traditional stand-alone dwelling to higher density residential construction such as townhouses, terraced housing or apartments.

Noise insulation in a building

Sound insulation is a building element’s ability to reduce the sound that goes through it. It is generally given in a single unit number as a guide to its effectiveness at limiting sound transmission, for example Sound Transmission Class (STC) 55 and Impact Insulation Class (IIC) 55.

This single unit number is a summary of the element’s sound insulation performance over a range of frequencies. It’s important to note the single unit doesn’t give you a full picture at all frequencies.

For example, an STC 55 timber wall won’t have exactly the same performance at all frequencies as a STC 55 concrete wall.

Types of sound insulation

There are generally two types of sound transmission to consider for buildings:

  1. airborne sound – noise originating in air, for example voices, music, motor traffic and wind.
  2. impact sound – noise originating directly on a structure by blows or vibration, for example footsteps above, furniture being moved, drilling and hammering the structure.

For wall assemblies, sound insulation should be thought of in two ways:

  1. external sound insulation – limiting noise from outside the building. This is generally provided by the building envelope.
  2. internal sound insulation – limiting sound transmission within the building, for example, inter-tenancy sound insulation or plumbing sound insulation.

The minimum requirements for preventing sound transmission through building elements are given in New Zealand Building Code Clause G6 Airborne and impact sound. Remember that if you undertake building work, it must comply with the Building Code regardless of whether it requires a building consent. You cannot interchange building products that form part of a building system unless you have followed a formal variation or amendment process.

Wall assembly and sound insulation

As a general rule, reducing sound transmission requires more mass or a separation of elements. Mass can be increased by using a thicker version of the same material or by using a denser material.
A range of factors need to be considered when selecting, installing or detailing noise control in wall, floor and ceiling assemblies (see Table 1). Always keep to the design specification for building elements that contribute to the sound insulation, particularly for inter-tenancy walls.

Building Code Clause G6 Airborne and impact sound has further information.

Table 1: Wall assembly construction to reduce sound transmission

Wall assemblySound transmission to considerWhat to consider
Bridging inter-tenancy walls Airborne noise Internal sound insulation Sound transmission by bridging occurs when a solid object connects two objects that otherwise would not have touched, for example in double stud or staggered stud wall constructions. This often occurs for intertenancy walls at the facade or at junction details, reducing the sound insulation of the inter-tenancy wall.

Solution: Prevent bridging by removing the bridging element or using a vibration isolation layer like rubber or a flexible sealant around the bridging element. The exact solution depends on the project.
Windows and openings Airborne noise External sound
insulation
Windows and openings are weak points for sound insulation. Generally, windows with thicker glazing and bigger air gaps between panes have better sound insulation.

Solution: Double glazing is slightly better than single glazing for sound insulation. However, it is not always better for low frequency noise such as planes and some traffic. If low frequency noise sources are expected, get advice from an expert.
Studs at 400 mm centres Airborne noise External sound
insulation
Studs at 400 mm centres make linings too rigid at certain frequencies, reducing sound insulation performance.

Solution: If sound insulation performance is a priority, avoid installing or detailing studs at 400 mm centres as there is no cost-effective solution to insulate the sound in this situation.
Lack of 'fluff' Airborne noise Internal and
external sound
insulation 
Fluff helps to absorb noise. Fluff is typically wool, fibreglass or polyester insulation installed in wall or roof cavities or between floors. A meaningful increase in the sound insulation of a building element typically needs a minimum density of fluff of 9.8 kg/m³. Generally, R1.8 thermal insulation will do the job.

Solution: There is little benefit from greater density fluff, although increasing the R-value will improve thermal performance. Adding internal linings to walls, ceiling or both, is more effective.
Cladding systems with polystyrene and sandwich panels have limited sound insulation performance. The best solution is to add mass to the construction.
Sarking  Airborne noise  External sound
insulation 
Sarking improves sound insulation.

Solution: If you value sound insulation and your building has sarking in the walls, roof or ceilings, try to keep it. However, be wary of potential bridging.
Gaps Airborne noise External and
internal sound
insulation
If a torch can be shone through a gap then noise will travel through it.

Solution: When sound insulation is a priority, try to avoid gaps.
Glues and sealants Impact and
airborne noise 
External and
internal sound
insulation 
Glues and sealants for sound insulating elements often need to remain flexible throughout their life to prevent noise transmission.

Solution: Stick with what has been specified and check if you have concerns. Changing glues or sealants to a non-flexible option or one that hardens over time can significantly reduce overall sound insulation performance.
Penetrations  Airborne noise  Internal and
external sound
insulation 
Penetrations are made by items such as fire collars, fans and socket outlets and can bridge inter-tenancy constructions or provide holes in the wall assembly.

Solution: Stagger socket outlets on either side of studs to prevent a weak point in sound insulation. Avoid having a socket on both sides of the wall in one cavity space, for example.
For better overall sound insulation performance, install fire collars and fans above ceilings that already have improved sound insulation. Fan ducting can also be sound insulating.

Please note building consent requirements and warranties may be affected where a system has been modified.

Quiz

1. Which of the following statements is true?

a. All noise control work must have a building consent.
b. The performance requirements for sound insulation are set out in Clause G6 of the Building Code.
c. All building work must have a building consent and comply with the Building Code.

2. For sound insulation, which are typically weak elements in an external wall assembly?

a. A window or door opening.
b. A hot-point/light switch/power socket.
c. A fire collar.
d. All of the above.

3. Can you interchange building products specified as part of a wall assembly system?

a. Yes, there are no real issues.
b. Sometimes, but it depends if it is an external or internal wall. It is not recommended, but the product must meet the Building Code to the same extent as the substituted product in all respects.
c. No, changing any part of a building system is not permitted.

Check your answers

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VisaView: Online tool for employing migrants

With the construction industry growing at such a fast rate, employers may want to employ more migrants to meet the demand for skilled builders and electricians. It’s important to know whether a potential employee can legally work here before hiring them.

VisaView is an online tool making it simple to verify if a non-New Zealand citizen can work for you. Immigration New Zealand developed VisaView, which allows registered employers to check if a prospective – or current – employee holds a valid work visa, the conditions of the visa and the expiry date. You can also confirm the person’s passport information using this system.

Any New Zealand employer can register to use VisaView. It’s a free service and once you’ve registered you’ll have a record of any enquiries you’ve made. This helps employers keep track of their obligations under the Immigration Act to check if an employee can work here.

VisaView on the Immigration New Zealand website has further information.

For further information about employing migrant workers, go to the Immigration New Zealand website or call the contact centre on 0508 967 569.

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From boats to buildings

Carl Saunders has been a handyman since he can remember. His family has always been big on boat building and he was set to follow in their footsteps. However, a stint mixing toxic-smelling resin for boats during the school holidays made him think his career should be in building buildings, not boats.

Carl SaundersCarl Saunders

He started his building apprenticeship at 17, and he’s been in the industry ever since. These days he’s the managing director of his own carpentry company.

“My role is varied and all encompassing. It’s a lot of roles for one person to fill but it’s the norm for most small building companies I think,” says Carl.

It’s a big job. In the office Carl is responsible for quoting, invoicing, scheduling, employment and health and safety. On-site he’s the supervisor, foreman, leading hand, health and safety leader and client communications manager.

He says even on top of his early starts in the office and long days out on-site, he still spends a couple hours each night in his home office dealing with paperwork.

Carl joined the LBP scheme in the 2011 and can see how important LBPs are in keeping New Zealanders safe, by providing quality products and services.

“The commitment to get things right and to be held accountable for your actions on important projects puts all LBPs on the right footing for good results. The benefits are then felt by the client and the overall housing stock in New Zealand.

“I believe the scheme is improving the quality of buildings we produce. We have a responsibility as LBPs to ensure that what we are building today will create a safe and healthy environment for all future users of our products,” Carl adds.

Carl has some great advice for up and coming LBPs, based on his own previous experience.

“I’d say it’s important to make the most of the opportunities being an LBP provides. The chance to improve your knowledge, improve the quality of your product, to lead by example and take pride in what we are producing for the future people of New Zealand.

“Being an LBP is being part of a legacy. We are the ones who care enough to say let’s get better at what we do and how we do it so that our housing future is assured,” says Carl.

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Notable decisions against two LBPs

The Building Practitioners Board (the Board) has recently handed down two noteworthy sanctions against two separate LBPs and has chosen to name each LBP due to the seriousness of the matters.

Both LBPs are licensed in Carpentry and, due to the nature of the complaints, both were issued strong penalties.

The first complaint was made against Feroz Ali in Auckland (C2-01401), and the second was made against Ah Sui Ah Sui in Waikato (C2-01450).

While the complaints differ in nature and result, it is important that all LBPs are aware of the pitfalls and avoid similar shortcomings.

Feroz Ali (C2-01401)

Mr Ali was found to have:

  • carried out building work in a negligent or incompetent manner
  • failed to comply with a building consent
  • failed to provide a record of work as required by the Building Act 2004 (the Act)
  • acted in a manner that brings, or was likely to bring, the LBP Scheme into disrepute.

The Board heard evidence that the consented plans and specifications required Mr Ali to install manufactured trusses. Mr Ali instead constructed the trusses on-site using second-hand timber and this became an issue when the building consent authority was notified of this by the designer (who was the Complainant). Mr Ali did not return to the site after this, despite being paid the full sum for the work. A Special Adviser, appointed by the Board, provided expert comment that Mr Ali was outside of his expertise as the plans specifically stated that an accredited manufacturer should design and construct the trusses.

As a result, the affected property had been constructed by Mr Ali in a manner that was not in accordance with the plans, using unspecified materials and techniques. Mr Ali had also displayed poor behaviour and understanding of the contractual and regulatory settings. The Board commented that the offending was at the higher end of the scale.

The Board noted that Mr Ali’s licence had previously been cancelled for other matters and so ordering cancellation was not an option. The Board issued Mr Ali with a $5,000 fine, an order for costs and publication of this decision due to the serious nature of the complaint.

Ah Sui Ah Sui (C2-01450)

Mr Ah Sui was found to have:

  • carried out building work in a negligent or incompetent manner
  • failed to comply with a building consent
  • failed to provide a record of work as required by the Building Act.

In this matter a Technical Assessor was engaged by the Board to provide an expert view of the building work carried out and supervised by Mr Ah Sui. The Board found that Mr Ah Sui failed to ensure the plans were followed and was not sufficiently familiar with modern building practices. This led to a breakdown in on-site processes and joinery, cladding, a pergola and internal plasterboard linings not being installed correctly.

The Board found that sequencing of tasks on the job was not in line with expected processes and that some building elements were both constructed and installed incorrectly. While finding that Mr Ah Sui had failed to comply with the building consent, the Board noted that some aspects of his deviation could have been accepted via a minor variation and did not hold Mr Ah Sui to account for these.

The Board also noted in its decision that it heard evidence that Mr Ah Sui had not followed the consumer protection measures in the Act correctly, due to lack of knowledge. Mr Ah Sui did not provide the home owner with a disclosure statement or written contract, which has been a legal requirement since January 2015.

The Board cancelled Mr Ah Sui's licence. The Board also ordered Mr Ah Sui to pay some costs towards the inquiry and the publication of this decision, again, due to the serious nature of the complaint.

What we can learn from these decisions

Poor on-site quality assurance and a lack of adherence to the consented plans led to both of these LBPs being disciplined. The outcome for both homeowners was less than desirable – the behaviour of these LBPs falls well below the standards expected of licence holders.

Having a solid grasp of regulatory and consenting requirements is vital to good quality and compliant building outcomes. Always ensure that you follow the specifications and instructions within those documents and if you have concerns it is appropriate to question the designer or the building consent authority. You should not undertake work that is outside the scope of the consented plans without obtaining approval and instruction from the local authority, the homeowner and the designer.

Understanding your regulatory and contractual obligations is also key and has been highlighted by these two complaints. Make sure you follow the rules around contracting and be aware that when a dispute arises, there is an appropriate way to approach the situation. If a dispute has arisen around the contract and you are unsure of what to do, seek advice from an authoritative source.

Lastly, make sure you are familiar with Part 4A of the Building Act, which deals with the consumer rights and remedies.

Do your homework – a contractor’s guide to rights and obligations when contracting with homeowners has further guidance.

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Recent determinations

Determination 2017/019

Determination 2017/019 considers whether proposed alterations to a school toilet block, with a reduced number of toilets, will comply with the Building Code to the extent required by section 112. The determination discusses the tests under section 112(1)(b) in regard to a reduction in the level of performance achieved in the existing building.

Background

The proposed alterations involved a classroom block and an adjacent toilet block that contained a storage room. The existing toilet block included four toilets, and three basins. The proposed alteration to the toilet block was to reduce the number of toilets from four to two to allow a wall to be constructed to increase the size of the classrooms.

The building consent authority (BCA) did not accept this proposal, so the agent amended the plans. The BCA granted this consent, but the agent wished to confirm that the initial proposal of two toilets would comply with the Building Code.

Discussion

The determination considered that it is appropriate to consider the complex as a whole, and the number of toilets provided within it to establish compliance of the toilet block. The Building Code does not require every building in a school complex to include toilets – it is sufficient if the complex as a whole contains an adequate number of toilets in convenient locations.

The dispute rested on the interpretation of section 112(1)(b) and the two different tests in 112(1)(b)(i) and (ii). The test in section 112(1)(b)(i) requires that after the alteration the building will to continue to comply with the provisions of the Building Code, if the building complied prior to building work being carried out. This part only applies if prior to alterations the building complied with the Building Code, and in this instance had an adequate number of toilets to comply with Clause G1.

The test in section 112(1)(b)(ii) only applies if the building prior to the alterations does not comply with the requirements of the Building Code. In that case it must comply to at least the same extent after the new work as it did before. In this instance, this would apply if the number of toilets were not adequate to meet the Building Code, so the building work could not reduce the level of performance, i.e. the number of toilets.

Therefore, the first consideration in applying section 112(1)(b) must be whether or not the building prior to the alterations complied with the provisions of the Building Code, in this case Clause G1.
In this instance, the number of toilets in the school complex, prior to building work being carried out, exceeded the level required by the Building Code, and the test under section 112(1)(b)(i) was applicable. The proposed removal of two toilets, while leading to a lesser level of performance, did not reduce the overall toilet numbers below that required by the Building Code.

The determination concluded that the building exceeded the compliance requirements and there is nothing in the Act to prevent a reduction in the level of compliance, i.e. fewer toilets, as long as the building still complies with the provisions of the Building Code.

Decision

The determination concluded that the proposed alteration to reduce the number of personal hygiene facilities in the toilet block to two toilets complied with Clause G1 of the Building Code to the extent required by section 112 of the Act.

Determination 2017/019 in full.

Previous determinations is a register of all previous determinations.

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Determination 2017/023

Determination 2017/023 considers whether a Type 6 automatic fire sprinkler system satisfies the Acceptable Solutions as a heat detection system. It also discusses whether there are any significant differences between a sprinkler system and heat detectors that would affect life safety.

Background

A commercial development containing three multi-level mixed use buildings, with a basement carpark running underneath the entire site, was consented by the building consent authority (BCA). The fire solution for the carpark was designed using a combination of Acceptable Solutions, including C/AS2 and C/AS7, which are a prescribed means of achieving compliance with the Building Code.

There was disagreement between the building consent authority (BCA) and the agent regarding the installation of heat detectors in the carpark. A Type 6 sprinkler system had been installed in the carpark, but the authority informed the agent that heat detectors were also required.

Discussion

The determination noted that while the substitution of heat detectors was not an explicit part of the Acceptable Solutions, it was considered within the cited Standards. The Acceptable Solutions refer to NZS 4512 and NZS 4541 in regard to the installation of the different fire safety systems. There are multiple instances within NZS 4512, the Standard for installing heat detectors, which establish that a sprinkler system can be substituted for heat detectors.

The determination also noted that a sprinkler system will activate when the temperature exceeds a predetermined value and will initiate a fire alarm, which satisfies the definition of a heat detector in NZS 4512.

However, the Acceptable Solutions do amend the Standards, and there were specific paragraphs that the BCA referred to as requiring heat detectors. C/AS7 requires where there is vehicle parking within a building it must have at a “minimum a Type 3 automatic heat detection system”.

The BCA took the word “minimum” to mean that the carpark must have heat detectors. However, the determination took the view that the “minimum” requirement is a baseline and a system that provides a higher level of performance will satisfy C/AS7. The sprinkler system is suitable as a method of heat detection, and has the additional benefit of controlling and potentially extinguishing a fire.

Therefore, the sprinkler system exceeds the minimum requirement of a Type 3 automatic heat detection system and satisfied C/AS7.

The decision

The determination stated that:

  • the BCA was incorrect to require Type 3 heat detectors alongside the Type 6 automatic fire sprinkler system
  • the use of a Type 6 automatic fire sprinkler system complies with Clause C4.3, if the system is compliant with either NZS 4515 or NZS 4541, and has the additional modifications to satisfy NZS 4512
  • the installed Type 6 automatic fire sprinkler system satisfies the Acceptable Solutions as a means of providing heat detection.

Determination 2017/023 in full.

Previous determinations is a register of all previous determinations.

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