Innovation
FEATURE
SECTION
Sorting out peak
performance
A vision of combining off-site construction benefits and a highperforming home led to the trial of a new building system and a new way
of delivering to the market. Important lessons were learned along the way.
BY VERNEY RYAN, BEACON PATHWAY INC.
Second trial house
THE NEW CATEGORY OF HOME project is
The Warmframe system comprises steel
the brainchild of New Zealand Steel and
framing, insulation and thermally broken
The second house in Hobsonville Point,
challenges the perception some people have
double-glazed windows. It can also have clad-
Auckland, used a Universal Homes design
that prefab is cheap.
dings, linings and coatings added in the factory.
with Warmframe to trial two alternative
It began with a vision of a home that would
methods of off-site construction – 2D walls
perform to a high standard – meeting the
Trial and demonstration
and 3D modules for framing, insulation and
Homestar 8 rating and Beacon’s HSS High
Next, a trial and demonstration phase
windows – and assess potential application
Standard of Sustainability – and be delivered
tested the system’s buildability and cost
in a medium-density design.
through off-site construction with its poten-
of construction, solved technical issues
It was assembled inside a factory, trans-
tial cost and time savings.
in a real-life situation and checked the
ported to site, constructed and finished
performance of the building system.
with claddings and linings using traditional
Five partners joined New Zealand Steel
in the project – Fletcher Aluminium,
The first trial was part of PrefabNZ’s HIVE in
methods. This provided an insight on
Frametek-RFS, InsulPro and Resene, with
Christchurch and used Salmond Architecture’s
delivery to the volume homebuilder market,
Beacon Pathway facilitating the process.
High Performance Houses design – flexible
and working in a business as usual environ-
modules suited to off-site construction – with
ment. Full thermal testing and monitoring of
the new Warmframe system.
this house has yet to be completed.
Innovation phase
The project began by bringing together
The house was fully built in the factory –
the partners’ technical knowledge and
framing, insulation, roofing, cladding, lining
Off-site construction learnings
understanding of their own products to
and windows – and transported by truck to
The two trials provided key learnings on
develop a new building system. The result
the site to be finished.
successful off-site construction.
– Warmframe – is a steel-frame building
Once complete, thermal testing and
system that can be built as walls, sections
imaging of walls and ceilings were under-
Both trials used existing house designs and
or entire buildings in a factory and has a
taken. The house was open to the public
this proved counterproductive to the usual
R-value significantly above Building Code
during 2013 and then sold, testing consumer
advantages of the off-site manufacturing
minimum requirements.
reaction and barriers to prefabrication.
process. Complex architectural features,
Needs to be design led
Build 143 — August/September 2014 — 59
Innovation
PHOTOGRAPH – MANNERING AND ASSOCIATES PHOTOGRAPHY
FEATURE
SECTION
The HIVE house is transported to site as an entire building.
such as wing walls, can add considerable
kept track of construction material, enabling
were good reasons for this, and it could be
time and cost.
greater scrutiny of materials used and more
improved with further delivery to scale, but
efficient supply and delivery.
the conclusion is that off-site construction
Preset material choices were also not
well suited to optimising off-site manufac-
needs to cover the entire process from design
turing. For example, vertical cedar cladding
A matter of scale
required additional timber framing attached
Testing various scales of off-site construc-
to the steel framing for fixing, adding cost
tion – entire 3D house, 2D walls, 3D modules
Prefabrication perceived as low cost
and complexity.
– enabled some high-level conclusions on
The experience of selling the HIVE house
efficiency of scale.
brought home a crucial barrier to off-site
A design-led process would have prioritised a cladding system more suited to
The 3D components were significantly
efficient off-site manufacturing and the steel
more complex to construct and transport
structure in this instance.
than the panelised components and also
Needs to be well organised
took up more factory floor space.
to on-site fit-out.
construction – the general perception that
a prefabricated house should be cheap.
The real estate agents reported that people
viewed a prefabricated house as being a
Leasing and setting up a factory was rela-
However, working in 3D means there is
tively simple and cost-effective. Using a good
potential for more of the finish to be done
process engineer helps establish stream-
in the factory. The HIVE house, for example,
This suggests that, while there are produc-
lined and efficient ergonomic construction
was fully enclosed and lined in the factory.
tivity, efficiency, quality and cost benefits
processes.
step above a portacom, despite being well
appointed.
Transportation of the 3D components,
from whole-house prefabrication, a partial
Quality and productivity were substan-
even as modules, was comparatively inef-
prefabrication approach – for example, wall
tively better in the factory than on site.
ficient given the volume being transported
panels – may be a more acceptable option
Having the correct materials and tools
and the need for specialised contractors.
in the market while still realising some of
available in the weatherproof, single-level
the benefits.
factory environment and a dedicated, expe-
It’s not business as usual
rienced workforce with set work hours can
Several challenges arose from delivering an
New language needed
significantly accelerate construction.
innovation using an already busy workforce
It also suggests that the industry needs to
with business as usual constraints.
develop more sophisticated language to
Working in a factory can also improve
safety and further reduce compliance costs.
The natural tendency to resort to the
In particular, second-storey windows can be
usual way of doing things works against the
Using the term ‘prefabrication’ may be less
installed at floor level without the encum-
introduction of innovation and the search
preferable than talking about off-site
brance of scaffold.
for out-of-the-box solutions.
construction, and the New Category of Home
Factory set-up can also improve goods and
The result was that the on-site construction
services delivery. A goods inwards system
phase was less efficient than expected. There
60 — Build 143 — August/September 2014
describe these innovations.
partners are dropping the term prefabrication from their lexicon.