Energy-led, non-domestic building refurbishment : decision support for a whole-building approach to improvement of operational performance
Abstract
Pressure is growing upon non-domestic building owners and occupiers to measure and
improve the energy performance, and associated carbon emission levels, of the portfolio
in which they operate. In line with this, the need for energy-led refurbishment of
existing buildings is increasingly evident, with approximately 60% of the current
building stock expected to still exist in 2050 and less than 1% being replaced annually.
However, energy-led refurbishment of existing non-domestic property faces a number
of barriers, including an ill-defined decision-making process and a lack of low carbon
skills required to guide building owners in this complex transition.
This thesis examines first, the need for a re-alignment of disciplines within the
construction industry to fulfil the growing requirement for low carbon skills, specific to
energy-led refurbishment. A comprehensive desk study was undertaken, evaluating the
competencies of the established construction industry professions, as defined by their
governing bodies. This was supported by structured interviews with users of large, nondomestic
property and industry professionals to establish whether a need existed and
how they proposed it be fulfilled. A deficiency in expertise was identified, and from
this a competency specification for professionals leading energy-led refurbishment in
existing, non-domestic property has been developed.
Second, this thesis explores the different forms of automated decision support within the
construction sector, identifying opportunities for a structured decision-making approach
to energy-led refurbishment. An optimum decision support tool (DST) process was
proposed, consisting of seven steps from assessment of the existing building’s state
through to continuous evaluation and improvement of the refurbished building. A key
module within this process was developed in detail to address the complex multiple
attribute decision making (MADM) approach required during selection of energy
performance improvement measure (EPIM). A set of assessment criteria, addressing a
variety of performance characteristics, was designed using an online Delphi survey with
a select group of ‘energy in buildings’ experts. The criteria range from short term
impact (EPIM installation) to long term impact (EPIM operation and disposal) upon the
existing property’s performance. Subsequent weighting of the assessment criteria in
terms of their relative importance was undertaken using the same expert group through
a paired comparison survey methodology. This revealed the relative importance of each
criterion, consequently aiding prioritisation of EPIMs within the optimum DST and
supporting decision-making.