| Having studied house design and
methods of construction around the world for over ten years,
Engineer John Melvin and his wife, decided that energy efficiency
and good design were the main criteria to be used in deciding
the means and method of construction for their new home, to
be located beside the sea in the picturesque village of Malahide
in North County Dublin. For these reasons, the clients opted
for the unique Century Homes R2000 superior Timber Frame system
of construction. Century Homes acted as sub-contractor to
the main contractor. Before approaching Century Homes, the
clients had developed a design with their own architect in
line with their requirements.
Design & Engineering:
The house is a two-storey over basement, encompassing 4,400
sq. ft. Century Homes were engaged to manufacture an R2000
Timber Frame structure to the clients' design. The R2000 system,
unique to Century Homes, brings the house as close to being
airtight as possible. Through the use of under-panel seals,
seals around windows and overlapping and sealing of vapour
barriers, this is achieved. As there are no permanent room
vents, ventilation and air quality are regulated through the
mechanical means of a Heat Recovery Ventilator. This system
extracts warm stale air from the house, while at the same
time taking in fresh air from outside and passing the two
through cross-over chambers; the warm air heating the cool
fresh air as it goes in. Working at an efficiency level of
95% means there is no noticeable drop in temperature within
the house itself.
Other notable features of the design are that the timber
construction is a cavity wall construction with the Timber
Frame inner leaf carrying all structural and wind loads. The
structure, comprising 140 x 38 CLS (Canadian Lumber Standard)
studs is sheeted on the outside with 9mm Canadian softwood
plywood, and a specially constructed breather membrane.
Outside this structure is a clear 50mm cavity with a brick
finish, then tied into the main structure. Contained in the
Timber Frame is 150mm of glass fibre insulation. A rubber
seal is located under all wall panels and seals are also used
extensively around windows and doors. The 1000 gauge vapour
barrier, contained on the inside, is wrapped around the walls
and over floor joists and silicone sealed when overlapping
and broken for services. This procedure required constant
attention from the main contractor to ensure all requirements
of the R2000 system were complied with. Full backup was given
by Century Homes to the main contractor to ensure this, and
continuous onsite inspections were carried out during all
stages of construction.
'Nothing more could be done to improve
the Energy Efficiency of this house' (NICER)
The National Irish Centre for Energy Rating is the organisation
that certifies buildings and awards them a rating based on
their energy efficiency. For example, a traditional block
built house with standard insulation is known to have an energy
rating in the region of 330 Kwh/m2 per year. A standard Timber
Frame structure containing 100mm of insulation in the walls
is known to have a rating or 180 Kwh/m2 per year.
This project, built to the Century Homes R2000 system has
a rating of 93 Kwh/m2. To date, this is the highest rating
achieved by any house in the country. In reality, the result
of this achievement is that this 4,400 sq. ft. home can be
heated for less than £1 per day.
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