feature Commercial scale hemp construction facility to reduce energy consumption. The key areas for consideration were airtightness, thermal mass and high levels of insulation. Construction The architects first became aware of Tradical Hemcrete at the concept design stage, while researching alternatives to the initial suggestions of either in situ or precast concrete as the primary walling element. Hemcrete is manufactured from locally grown hemp shiv - the woody core of the plant - which is mixed with a lime-based binder to form a composite material which is carbon negative and has a high thermal inertia, giving it excellent thermal and acoustic properties, but the suitability of the product for a large scale commercial project was untested . Hemp spraying had been used extensively on domestic projects but not before on a building the size of the Wine Society's warehouse project, where calculations had suggested that to accommodate the required volume of wine (about 3,500 , 000 bottles) within the 3,250m 2 floor area, the building would have to be up to 21 m high. A visit to the recently completed Adnams brewery warehouse in Southwold confirmed the benefits of hemp in terms of thermal performance and carbon emissions, but did not resolve the design team's concerns that this product, which had previously been used in a domestic cap acity, had no track record as part of a large scale commercial development Winner oftwo awards, and recently short-listed for the national RICS Sustainability Award, The Wine Society Warehouse, Stevenage, is a fine example of a simple green industrial building. It uses a combination of insulating external envelope and interior thermal mass - the wine - to achieve an impressively low energy consumption, avoiding all forms of bolt-on bling. Olwyn Pritchard and Geoff Yeates report ... In 2007, the Wine Society realised it needed a fourth wine warehouse at its main Stevenage site and appointed local arcllitects and town planners Vincent and Gorbing Associates to lead their selected design team which included MLM Consultants as both structural and services engineers , and project managers Millbridge. With ever-in- creasing energy costs a major concern , the society was keen to limit. as far as possible, the additional burden that a new building would impose on the site's running costs and the g rowing need for an energy efficient building became a fJr ll 'T1ary fe ature of the design brief. Green Building • T'he Wine Society is a non profit making wine organisation owned by its members. It was established in 1874 for the purpose of sourcing, importing, storing and distributing wine to its members, all of whom are shareholders . Most of its operations are located in Steven age, Hertfordshire, from where it provides over seven million bottles of wine a year to its 100, 000 members across the country. Vincent and Gorbing has been actively involved in sustainable architecture since 1999 when the practice's first passively ventilated office building, the headquarters of an expanding housing association, was commissioned . Once completed, the newly occupied office building became the focus of a long-term exercise in modelling the diurnal and nocturnal airflows in naturally ventilated buildings which was carried out by the Cambridge University-based BP Institute for Multiphase Flow. Building on this experience, the practice has put sustainability at the core of its design philosophy for all new projects. The initial design team meetings with The Wine Society involved discussions about sustainability and the need to retain a steady-state envir onment within the new storage 16 . Winter 2010 Green Building 17 . Top, far left : the outside of the finished building. Here can be seen the final cladding over the hemcrete panels and also the external aspect of the Kalwall insulated walling system. Above : the Kalwall wall insulating glazing system allows light to enter the building and thus help to save on artificial lighting. Left and insets: The hemcrete panels being constructed, distributed and installed. Nevertheless, the unique properties of Hemcrete - thermal mass, carbon negative, air permeability. etc - made it the first choice for the external envelope. Vincent and Gorbing and the design team developed the idea of using the sprayed form of Hemcrete in large pre-fabricated wooden cassettes, measuring 2.4m high, 3.6m wide and 300mm thick. The cassettes were framed up using standard TJI joists. with the backing made from Samox board, which is both breathable and vapour permeable . like Hemcrete, and which forms the visible inside face of the external wall construction. The cassettes were then transported to a disused airfield in Suffolk where they were sprayed and cured before delivery to the site in Stevenage. Here they were stacked up and tied back to a structural steel frame for both support and stability. Between the walling Winter 2010
Transcript
feature Commercial scale hemp construction
facility to reduce energy consumption The key areas for
consideration were airtightness thermal mass and high
levels of insulation
Construction The architects first became aware of Tradical Hemcrete at
the concept design stage while researching alternatives to
the initial suggestions of either in situ or precast concrete
as the primary walling element Hemcrete is manufactured
from locally grown hemp shiv - the woody core of the
plant - which is mixed with a lime-based binder to form
a composite material which is carbon negative and has a
high thermal inertia giving it excellent thermal and acoustic
properties but the suitability of the product for a large
scale commercial project was untested
Hemp spraying had been used extensively on domestic
projects but not before on a building the size of the Wine
Societys warehouse project where calculations had
suggested that to accommodate the required volume of
wine (about 3500000 bottles) within the 3250m 2 floor
area the building would have to be up to 21 m high
A visit to the recently completed Adnams brewery
warehouse in Southwold confirmed the benefits of hemp
in terms of thermal performance and carbon emissions
but did not resolve the design teams concerns that this
product which had previously been used in a domestic
capacity had no track record as part of a large scale
commercial development
Winner oftwo awards and recently short-listed for
the national RICS Sustainability Award The Wine
Society Warehouse Stevenage is a fine example
of a simple green industrial building It uses a
combination of insulating external envelope and
interior thermal mass - the wine - to achieve an
impressively low energy consumption avoiding all
forms of bolt-on bling Olwyn Pritchard and Geoff
Yeates report
In 2007 the Wine Society realised it needed a fourth
wine warehouse at its main Stevenage site and appointed
local arcllitects and town planners Vincent and Gorbing
Associates to lead their selected design team which
included MLM Consultants as both structural and services
engineers and project managers Millbridge With ever-inshy
creasing energy costs a major concern the society was
keen to limit as far as possible the additional burden that a
new building would impose on the site s running costs and
the g rowing need for an energy efficient building became a
fJr llT1ary feature of the design brief
Green Building bull
The Wine Society is a non profit making wine organisation
owned by its members It was established in 1874 for the
purpose of sourcing importing storing and distributing
wine to its members all of whom are shareholders
Most of its operations are located in Steven age
Hertfordshire from where it provides over seven million
bottles of wine a year to its 100000 members across the
country
Vincent and Gorbing has been actively involved in
sustainable architecture since 1999 when the practices
first passively ventilated office building the headquarters
of an expanding housing association was commissioned
Once completed the newly occupied office building became
the focus of a long-term exercise in modelling the diurnal
and nocturnal airflows in naturally ventilated buildings which
was carried out by the Cambridge University-based BP
Institute for Multiphase Flow Building on this experience
the practice has put sustainability at the core of its design
philosophy for all new projects
The initial design team meetings with The Wine Society
involved discussions about sustainability and the need to
retain a steady-state environment within the new storage
16 Winter 2010 Green Building 17
Top far left the outside of the finished building Here can be seen the final cladding over the hemcrete panels and also the external aspect of the Kalwall insulated walling system
Above the Kalwall wall insulating glazing system allows light to enter the building and thus help to save on artificial lighting
Left and insets The hemcrete panels being constructed distributed and installed
Nevertheless the unique properties of Hemcrete shy
thermal mass carbon negative air permeability etc - made
it the first choice for the external envelope Vincent and
Gorbing and the design team developed the idea of using
the sprayed form of Hemcrete in large pre-fabricated
wooden cassettes measuring 24m high 36m wide and
300mm thick
The cassettes were framed up using standard TJI
joists with the backing made from Samox board which
is both breathable and vapour permeable like Hemcrete
and which forms the visible inside face of the external
wall construction The cassettes were then transported
to a disused airfield in Suffolk where they were sprayed
and cured before delivery to the site in Stevenage Here
they were stacked up and tied back to a structural steel
frame for both support and stability Between the walling
Winter 2010
Feature Commercial scale hemp construction
cassettes and the external cladding (a composite metal
panelling system) is a void quite literally a breath ing space
which provides natural ventilation for the Hemcrete
Extensive discussions followed with the structural
engineers to see if the Hemcrete cassette system could be
adapted for the roof construction Unfortunately structural
limitations and cost constraints precluded the use of this
approach and a more conventional roof construction was
adopted
From an ea rl y stage in the monitoring process it was
clea r that the building was demonstrating remarkable
temperature stability with very little use of the MampE
