C o s t – E f f e c t i v e n e s s M e a s u r e m e n t M o d e l
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The ground floor is a solid concrete thermal mass with expected U-value of 0.15W/m
2
K.
A underfloor heating system is being considered. The entrance draught lobby on the
north acts as a buffer zone to reduce heat losses. A machine room containing a hot
water tank and inverters for photovoltaic (PV) & wind turbines (if installed), has been
placed on the north side of the unit as it would generate heat when the house comes into
operation. The large windows on the south side are triple-glazed with expected U-value
of 0.8W/m
2
K allowing natural light and solar gains. A cloth drying space has been
provided in the south-east side to minimise use of a tumble dryer. This area and hallway
are connected to a balanced mechanical ventilation heat recovery (MVHR) system which
is connected to a PV/T roof for the extraction of the heated fresh air. Through the open
corridor and staircase, the warm air from the drying area and machine room may be well
circulated due to the stack effect (Fig.2).
Figure 2: Proposed Ground Floor Plan (Evans et al. 2012)
The first floor is accessed by a staircase from the ground floor and introduces the
concept of a home office space. In the family rooms such as lounge and kitchen, an
open plan has been adopted to eliminate unnecessary partitions that increase the initial
costs while increasing flexibility for the usage (Fig.3). These areas can be
interchangeable. For instance, the dining table can be placed comfortably in front of the
large picture window that provides a panoramic view of the large park. Also, it can sit in
the area adjacent to the kitchen, overlooking the garden at the rear. The south-west
facing window above the kitchen and dining area allows for both the extraction of
unwanted smell and the entry of natural sunlight to the family room. Generally, the south-
facing contribute to securing solar gain and natural light.
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