Analysing steady state models for dwelling carbon performance

In the UK, 24% of all carbon dioxide emissions are from the residential sector (Office for National Statistics, 2010), and of those only 4% have been built since 2002 (Office for National Statistics, 2010), under EPBD-compliant Building Regulations requiring greater energy efficiency. Therefore, the UK existing building stock must be improved to meet the UK and EU emissions targets.
The current Government’s flagship policy is the Green Deal: a loan scheme offering homeowners finance to improve the energy efficiency of their home, paid back through electricity bills. These payments must cover the full cost of the work within 25 years: known as the Golden Rule. The loan stays with the home, not the homeowner, so it does not prohibit the purchasing of measures that have a long payback.
To estimate emissions from the residential sector, the UK uses the Standard Assessment Procedure (SAP), a compliance tool designed originally to provide Building Control and Planning Authorities with proof of compliance. It is a simple steady state calculation that estimates fuel costs and emissions associated with heating and lighting a home. The Green Deal will use SAP methodology to estimate savings of chosen options, to decide eligibility for finance (the aforementioned Golden Rule).
This research identifies some of the flaws with this approach and investigates the weaknesses and sensitivities of the model, when compared with dynamic simulation tools such as the IES<Virtual Environment>.