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
243
Conclusions
This study led to the development of a cost-effectiveness measurement model which
consists of (1) steps towards identification of design components and approaches and
the potential combinations and assessment of energy consumption, operational energy
cost and CO
2
emissions, as well as (2) a value visualisation analysis matrix. In order to
identify design options, the energy and resource usage patterns of NRGStyle’s existing
house were examined using EWGECO’s gas, electricity and water monitor. Domestic
energy wastes could be calibrated, reduced or eliminated by displaying the energy and
resource usage.
This study highlighted significant effects of building orientation and thermal properties on
reduction of energy demand while proper combination of renewable energy
technologies—e.g. the operation of an air source heat pump alone contributes to
increasing CO
2
emissions although the energy use can be reduced due to high COP.
When the delivery of zero carbon homes is desired, a biomass heating system (e.g.
pellets) can be considered as a relevant design option that can relatively easily lead a
well insulated house to zero carbon operation. However, zero energy housing targets
may hardly be achieved by the use of a biomass boiler although the house is equipped
with a moderately sized PV system. Also, the proposed model helped clarify that a
traditional combi-boiler is considered as a cost-effective heating system which is cheaper
to use than air source heat pump or biomass counterparts. However, the use of a combi-
boiler may not contribute to the delivery of net zero energy housing unless oversized PV
systems can be installed.
The proposed cost-effective measurement model helps visualise values of properly
combined design solutions applicable to the delivery of low to zero energy housing. The
tool developed assists stakeholders’ design decision making in consideration of the
operational energy cost today and in the future. The future value of design choices can
lead to the estimation of products’ payback period when the initial costs are explicit.
Acknowledgements
The authors would like to express their sincere gratitude to CIC Start Online for the
financial support and equally to Dr Branka Dimitrijevic, Director, for her constructive
guidance on the grant application. Also, we would like to thank deeply Mr Norman Smith
and Ms Alison Quinn, NRGStyle Ltd., for the provision of the construction site documents
and the company’s aspirations accompanied by their patient, effective collaboration.
References
BAYFIELD ENERGY, 2012, Ground Source Heat Pumps explained
<
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BRE, 2009, The Government’s Standard Assessment Procedure for Energy Rating of
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EVANS, M., SMITH, N., RINGAILA, A., QUINN, A., NOGUCHI, M., ROHATGI, A.,
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Prestwick.
ENERGY SAVING TRUST, 2012a, Ground Source Heat Pumps
<
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