PM23 H1 Guide TUMU 210x287mm 4.0 LR - Flipbook - Page 4
COMPLIANCE
METHODS
SCHEDULE METHOD
This method contains tables of minimum
construction R-values for different building
elements. A building complies with this method
if its thermal envelope components – roof, walls
(usually external), windows, doors, skylights and
floor – are insulated to meet or exceed R-values
from the tables. The R-values vary depending on
the climate zone a building is in.
Designers use a different set of tables if building
elements contain embedded heating systems in
ceilings, walls or floors.
b) The combined glazing area on the east, south,
and west-facing walls (refer to Appendix D) is 30%
or less of the combined total area of these walls.
c) The skylight area is no more than 1.5m2 or
1.5% of the total roof area (whichever is greater).
d) The opaque door area is no more than 6m2 or
6% of the total wall area (whichever is greater).
BRANZ provides a Schedule Method tool here:
branz.co.nz/energy-efficiency/h1-schedulemethod-tool
The Schedule Method shall only be used where:
a) The glazing area is 30% or less of the total wall area.
CALCULATION METHOD
The H1 Clause of the Building Code
regulates the energy efficiency of the
built environment – covering wall, floor
and ceiling insulation, as well as the
thermal performance of windows and
doors. There are major increases in
thermal performance requirements across
the building envelope, indicated through
higher construction R-values for different
building elements. Read more on the
different methods used to determine
construction R-value below
This method includes simple equations and
allows a building to have different insulation
combinations, as long as the overall thermal
performance is comparable to or better than
the reference* building, which is insulated in
accordance with the Schedule Method.
In practice, this means it allows trading off between
elements so you can use higher R-values for some
elements than in the table shown and lower R-values
for others.
However, there are limits. Using the Calculation
Method, the minimum R-value for a floor, wall or
roof building element is 50% of the schedule method
R-value for that building element. There is no
minimum for doors and windows.
Using the Calculation Method, the window area of
the building can be no greater than 40% of the total
wall area.
*The ‘reference’ building heat loss equations can be
calculated using Table 2.1.3.4A in H1/AS1.
BRANZ provides a Schedule Method tool here:
branz.co.nz/energy-efficiency/h1-calculationmethod-tool
W
ithin the acceptable solutions and
verification methods for H1 Energy
Efficiency, there are three methods to
comply with the minimum R-values for building.
•
The Schedule Method (table)
•
The Calculation Method (simple online calculator)
•
The Modelling Method (software)
MODELLING METHOD
Which method the designer decides to use will depend
on a variety of factors, including but not limited to:
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•
Whether the building is smaller or larger than 300m².
•
The size of the glazing area of the building.
•
The orientation of the building.
TUMU H1 GUIDE
This method provides the greatest amount
of flexibility. It is used to assess the energy
performance of a proposed building by using
a simulation of the building to predict its space
heating loads and cooling loads.
Verification of the design is achieved by using computer
modelling to demonstrate that the energy use of the
proposed building design does not exceed the energy
use of the reference building described above and in
more detail in Appendix D of H1/VM1.
This is compared with the space heating loads
and cooling loads of a reference building that
is the same shape, dimensions, and orientation
as the proposed building, as well as building
elements with the relevant construction R-values.
This method is used if the window area of a building
is greater than 40%.
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