1. THE A-TEAM SUSTAINABLE DESIGN PROJECT
Chris Aoun - Hakeem Buge - Edmund Chan - Matei Predescu - James Taylor
University of Exeter
MaterialsEnergy Performance Certificate
An Energy Performance Certificate (EPC) is required upon
construction of any new build property (gov.uk, 2015). The
program iSBEM was used to produce an EPC to predict the
houses final grade once constructed. All wall dimensions, U
values, and building energy systems were inputted.
The energy performance certificate shows that the house is
expected to achieve an EPC rating of 10, which is equivalent
to an A rating. This rating proves the houses inherent
sustainable nature, and illustrates its low energy
requirements. This is a rating only 0.1% of UK homes
manage to achieve (easyepc.org, 2012). This EPC rating is
only a prediction, and will need to be carried out in full once
the house is fully constructed. It is likely that when this
happens the EPC rating will drop due to differences between
initial designs and the final construction. The minimum
rating needed for an A grade is 25, meaning there is plenty
of room for the rating to drop whilst still being an A grade.
Floor Plans & Fire Escape
Introduction
As the project stipulates, the property is designed to be a truly sustainable, beautiful and enjoyable family house located
on the site of an abandoned shallow stone quarry near Carharrack, close to Redruth. The building is required to have a
kitchen, a lounge, a dining room, 4 bedrooms, garage space for 2 vehicles, storage space etc. The design meets all of set
requirements whilst making strides to minimize energy consumption, carbon emissions (by incorporating renewable
energy technologies)
iSBEM
The program iSBEM was used to produce an England Building Regulations part L 2013 report, and an Energy
Performance Certificate. Together, they provide a full energy breakdown of the property. The results from the
building regulations report are displayed in graphical format.
The table above shows (in green) the U values of all the structures in the house and all
of them fall within the U-limit, proving that the insulation up to a high standard. U
values are used as a good indication of the heating requirements of a house and by
reducing the heating requirements for this specific house, the heat pump will have less
demand (meaning more storage) and, in turn, it will mean there is less of a load on the
PV panels especially during periods of peak demand.
The above information was used to produce the following annual heating demand charts.
The chart below shows clearly that there is no fuel usage and approximately 14kg of CO2 are
released per m2. However, 9kg of these 14 are displaced by the use of the photovoltaic panels. The
program has estimated that the remaining of the electricity will be grid imported however, since
the house is off-grid the remaining 5kgCO2/kg will be displaced by the backup bio-diesel generator.
Building Regulations
The first regulations that were considered are under category M of the building regulations. These
regulations consider the access and use of the building. It was decided that the property will be
wheelchair accessible to comply with category 1 of the regulations. The following dimensions
were all exceeded.
The minimum outside slope and path requirements were also considered, along with the
minimum window sizes. There is a minimum lux requirement that must be met in each room.
These requirements have been met, and in open areas exceeded. Downstairs toilets have
minimum dimensions they must abide by to allow wheelchair access (8). These requirements were
exceeded.
Foundation: The type of foundation used for this house was dictated by the type of soil present
on the site, which is predominantly clay. Clay has the negative characteristic of being expansive
when wet. The displacement of the wet soil can damage the footing of a building. To mitigate this
risk a slab on grade foundation was chosen for this project. In this type of foundation, the entire
building is erected over a concrete slab of a significant thickness. According to the builder’s guide
on home building and renovating UK (homebuilding.co.uk, 2015) a foundation between 700mm –
1000mm would be sufficient, we opted for a foundation depth of 1000mm. The bottom plate of
the wood frame floor will be anchored into the slab with anchor bolts and washers. The wall stud
should be securely connected to the band joists and bottom plate using approved metal clips or
straps.
Frame: The frames for the house were sourced from a Cornish framing company.
Their closed panel products are insulated to the demands of their clients. The
insulation type used in this building is 235mm of Rockwool. (mineral wool). The walls
are made from timber frame, they have service voids, a vapour layer and wood
cladding on the outside finishing. The ensemble timber frame gives the walls a U-
value of 0.13 W/m2K. The roof of the building is a pitched roof, the insulation is
located on the pitched rafter line, the rafters are 150 mm deep and the insulation
between rafters is 140 mm thick. The roof has a well ventilated air layer, a breather
membrane as well as an unventilated air layer and standard wallboard plasterboard,
which is also supplied by Frames UK. The U-value was found to be 0.18 W/m2K
The flooring: The chosen floor design is a suspended
timber ply on timber flooring. The floor is constricted using
wood joists resting on double plates Floor joists will be
supported by exterior walls as well as interior load-
bearing walls. Smaller sleeper walls are often used to add
support below suspended wooden floors at ground level.
The floor surface us constructed by laying wooden boards
sheets across the joists. (The DIY Network, 2016) The
floor joists are included in the framing supplied by Frame
UK.
The insulation in the floor system is 75mm thick giving the
floor a U-value of 0.25 W/m2K. The floor is covered with
chipboard 20mm thick.
(All images in materials section sourced from RockWool.co.uk 2016)
Roof insulation
Floor insulation