Title:
|
Homes of today for tomorrow : a study of the potential of the existing housing stock to perform to new standards of energy efficiency
|
In June of 2003 a revised Part L of the Building Regulations Approved Documents increased
the stringency of requirements pertaining to the conservation of fuel and power in buildings.
These regulations are indicative of the increasing pressure that is being applied to
legislators, architects and builders to improve the energy efficiency of the British
construction industry. In particular, the new Part L1 significantly increases the demands
placed on housing. Furthermore, these regulations no longer apply purely to new build
dwellings, but to any building work that is deemed to constitute 'material alterations'. While
the government's commitment to driving forward standards of 'good' new housing is clear,
the extent to which the existing, and increasingly elderly, housing stock can be improved is
less certain. This study investigates the potential for increasing the energy efficiency of
existing dwellings, up to and beyond current standards.
A survey of ten percent of the dwellings in Neath Port Talbot County Borough is used to
analyse predominant physical characteristics of housing. The houses are clustered into
twenty groups based on these characteristics.A n actual dwelling is then chosen that is most
representative of each of the groups, and is surveyed in detail. Dynamic computer models of
these dwellings are used to evaluate the impact of a series of different energy efficiency
measures, ranging from simple home improvements to more complex refurbishments.
Returning to the larger scale, conclusions are drawn relating to the degree that the energy
efficiency of existing housing stock can, and should, be improved.
The efficiency of the houses as existing is significantly influenced by dwelling type, age,
occupancy and the degree of care that has been provided by owners and occupiers in
maintaining their homes. However, some of the emergent dwelling types have more efficient
physical forms than others. Improvement of glazing has the biggest impact on the energy
consumption of most of the dwellings, typically reducing fuel bills by a third, although it is
not likely to be the most cost effective measure. When coupled with replacement of the
boiler, saving on average 17.5% of the heating load, this unanimously results in a very
significant saving. Improvement of the dwellings generally to current standards typically
reduces the energy required for space heating to one third of current heating loads.
Terraces and flats provide very efficient forms for improvement. The smaller semi detached
houses perform acceptably at higher standards, whereas larger semi- and detached homes
and particularly bungalows are intrinsically less efficient. Orientation plays an important part
in achieving higher standards. Large, recently built houses tend to have a uniformity of
windows that lose energy, while older houses are very often more thoughtfully and
responsively designed. Improvement of the dwellings to super-insulated standards reduces
the overall energy required for space heating to only a seventh of the current demand. Only
the smallest, most sheltered homes with good orientation can achieve autonomous
standards, and this requires air-tight fabric and energy from renewable sources.
|