KĀINGA ORA - Concrete New Zealand Incorporated - Concrete NZ

Concrete New Zealand
    Incorporated

                Submission to

           KĀINGA ORA
                       on

     PERFORMANCE REQUIREMENTS’
           CONSULTATION

     M-134: Design Performance Requirements

     M-135: Product Performance Requirements

                   4 July 2021

4 July 2021

Kāinga Ora – Homes and Communities
National Office
PO Box 2628
WELLINGTON 6140

By email: performancerequirements@kaingaora.govt.nz

Dear Madam/Sir

PERFORMANCE REQUIREMENTS' CONSULTATION - M-134 & M-135

Concrete New Zealand (NZ) represents a membership of more than 500 corporates and
individuals who make a significant contribution to the New Zealand building sector.
Concrete NZ speaks with a unified voice on behalf of the cement and concrete industry.

In line with this mandate Concrete NZ welcomes the opportunity to provide comments
on Kainga Ora’s Performance Requirements' Consultation - Design Performance
Requirements (M-134) and Product Performance Requirements (M-135).

GENERAL COMMENTS

Fire Safety
Medium density housing sees occupants living in greater concentrations compared to
standalone suburban dwellings. As such, the outbreak of fire has catastrophic potential.

Concrete NZ urge Kāinga Ora to specify that all structures, linings and fire protection
measures are built from durable products (materials) that are resistant to accidental or
wilful damage, as any compromise will reduce fire performance.

The presence of combustible products can accelerate a fire, enabling it to cross spans.
This was seen in the 2017 Grenfell Tower fire in London. Subsequently, fire protection
systems were re-evaluated worldwide, with an emphasis on combustible products.

Damaged fire protection layers offer fire an opportunity to take hold. For instance,
intumescent paint can easily become scratched or cracked, while the fire lining of
plasterboard is susceptible to damage upon impact. This loss of integrity can go
unnoticed, with potentially tragic consequences.

Concrete NZ recommend that all fire protection measures are made from durable,
damage resistant products. Incombustible concrete walls and floor slabs prevent fire
spread. Concrete columns can be fire rated to prevent collapse for 4 hours or longer.
Concrete cladding and envelope systems such as composite thermally insulated types
provide long lasting and durable fire protection to both sides of the envelope.

Concrete NZ believe that to provide additional safety, all life and property ratings for
Kainga Ora dwellings should exceed the New Zealand Building Code minimum currently
set at 60 minutes (or 30 minutes when a sprinkler system is present). The minimum
should be increased to 90 minutes as is the case in many European countries.

Raising the fire rating to 90 minutes will add cost to current lightweight construction.
However, products that offer inherent passive fire resistance, such as concrete (precast
and in-situ) and concrete masonry, can already meet the suggested fire rating increase.

Noise Disturbance
Exposure to noise disturbance has been shown to cause a range of health problems
ranging from stress, poor concentration, productivity loss in the workplace, as well as
communication difficulties and fatigue due to lack of sleep. More serious issues such as
cardiovascular disease, cognitive impairment, tinnitus and hearing loss can also occur.

In 2011 the World Health Organization (WHO) released a report titled Burden of Disease
from Environmental Noise, which collated data from various large-scale epidemiological
studies of environmental noise in Western Europe over a 10-year period.

Noise disturbance is of more concern in medium density housing environments. Stereo
systems, DIY activities and animated conversations result in constant sound waves,
which at low frequencies can travel long distances through lightweight construction.

The New Zealand Building Code Clause G6 does not currently include any limit on low
frequency noise performance. As such, Kainga Ora should apply custom requirements
that exceed the Building Code to accommodate low frequency sound attenuation.

Concrete slabs and walls offer above average sound performance due to their mass.
These simple systems are time/cost effective and available to address noise disturbance.

Thermal Mass
Through passive solar design, concrete’s thermal mass can help maintain a comfortable
environment year-round by absorbing the sun’s energy during the day to prevent
overheating, and then radiating that energy in the night as the temperature drops.

Using thermal mass in a dwelling does not increase costs. While it is aesthetically
pleasing to grind and seal the concrete floor, there will be immediate cost savings from
no carpet, as well as medium/long-term cost savings from reduced electricity use.

Other advantages of thermal mass include durability, damage resistance and the lack of
volatile organic compounds (VOCs) often found in carpets, which can trigger allergies.
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Airtightness
Minimising a dwelling’s air infiltration through concrete floors and walls lessens the
need for space heating and cooling. Airtightness helps to keep dwellings warm in winter,
cool in summer and also prevents moisture from being carried inside.

In short, airtightness reduces overall energy dependence through greater energy
efficiency. The outcomes are a comfortable living environment, cost savings from
reduced electricity use and a reduction in a dwelling’s operational carbon footprint.

Durability
A durable dwelling provides a longer-life over which the economic and environmental
costs incurred in its construction are paid-off/off-set. If you double the life of a dwelling,
you halve the economic and environmental impacts of its construction.

Durable building products require less repair and replacement, so the cost and carbon
footprint invested in them can be spread over an extended period. In addition, the
inconvenience and stress to the dwelling occupant and owner are minimised.

A dwelling designed and built for 100 years offers advantages compared to the same
dwelling designed and built for 50 years. Over its extended life cycle, the initial cost and
carbon footprint of the more durable 100-year dwelling makes sense.

Concrete structural frames, floor slabs, walls, facade panels and other components offer
inherent benefits over a longer lifecycle when compared to lightweight alternatives.

Conclusion
Concrete NZ recommend that in the interests of occupant wellbeing, Kainga Ora’s Design
and Product Performance Requirements demand the use of durable, low-maintenance,
fire resistant and sound insulating products.

Furthermore, to assist New Zealand achieve its zero carbon objectives, any building
product used should contribute to the dwelling’s energy efficiency.

Concrete NZ would like to thank Kainga Ora for providing the opportunity to comment
on the Performance Requirements' Consultation - Design Performance Requirements (M-134)
and Product Performance Requirements (M-135).

Yours faithfully

Rob Gaimster
CHIEF EXECUTIVE
Concrete NZ

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