PM23 H1 Guide TUMU 210x287mm 4.0 LR - Flipbook - Page 12
BUILDINGS
OVER 300M2
The new requirements for large buildings aim to reduce the emissions and energy used
when heating and cooling a larger building by 23% on average over previous minimum
status quo requirements
T
his overview of changes applies to ‘Buildings
greater than 300m²’, including but not limited
to buildings classified as offices, retail, schools,
hotels, restaurants, etc. The specified area – greater
than 300m² – is based on the occupied space of
the building.
These changes only affect new construction or
existing properties undergoing changes to the external
thermal envelope, which will require a building consent.
Industrial buildings are not currently required to be
energy efficient, so sit outside the scope of this work.
However, if there was an office within a warehouse, or
an industrial building, that office would have to comply
with the updated requirements.
WHAT’S CHANGED?
MBIE changed the roof, window, wall and underfloor
insulation requirements for buildings larger than 300m².
These changes are outlined in the table below.
•
Lift minimum levels of insulation for large buildings
to make them more comfortable and easier to heat
and cool.
•
Introduce a new climate zone map to better
recognise variations in climate around
New Zealand, and reflect this in the proposed
requirements.
•
Provide a clear compliance pathway for these
buildings by separating the requirements for large
buildings into their own acceptable solution and
verification method.
The acceptable solutions for H1 (H1/AS1 & H1/AS2)
contain tables and a simple calculation method to
determine the R-values in a building. Only H1/AS2 can
be used for ‘Buildings over 300m²’.
H1/AS2: This acceptable solution can be used for
larger buildings with an area of occupied space
more the 300m². It does not include provisions
for housing. To determine the minimum insulation
requirements, this document contains two methods –
Schedule and Calculation.
COMPLIANCE PATHWAYS
There are different ways to show that a building
complies with the Building Code.
One way is through the use of acceptable solutions or
verification methods. To meet the increased insulation
requirements of H1 Energy Efficiency in buildings more
than 300m², MBIE updated H1/AS2 and H1/VM2.
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The new editions of Acceptable Solution H1/AS2 and
Verification Method H1/VM2 aim to:
The verification methods for H1 (H1/VM1 & H1/VM2)
contain rules for design professionals to use computer
modelling and software to determine the minimum
TUMU H1 GUIDE
amount of insulation required in a building and to
demonstrate compliance with the Building Code.
Only H1/VM2 can be used for ‘Buildings over 300m²’.
H1/VM2: This verification method can be used for
larger buildings with an area of occupied space more
the 300m². It does not include provisions for housing.
Unlike H1/VM1, there are no limitations on the type
of construction elements and specific designs the
document covers for these buildings.
The method used to determine the minimum insulation
requirements is based on computer modelling and
known as the Modelling Method. Users of this method
are expected to have specific training and expertise
to conduct the simulations.
ALTERNATIVE SOLUTIONS
If designers or builders want to comply with the
Building Code performance requirements directly,
they may also choose to use an alternative solution
as a compliance pathway.
This will usually require specific design and input
from suitably qualified people, such as architects or
engineers. Alternative solutions are not deemed to
comply with the Building Code and must be assessed
by the relevant Building Consent Authority on their
individual technical merits.
For the insulation requirements, the alternative solution
must satisfy the Performance Criteria in clause
H1.3.1(a).
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