An investigation into energy saving via retrofit compared to replacement housing

Abstract

The global rise in air and oeean temperatures and the recent weather extremesdemonstrate that climate change is unequivocal. The UK has legislatively committed to an 80% reduction in CO2 levels by 2050 based on the 1990 level. Its residentialsector is responsible for 30% of the CO2 emissions where by space heating isresponsible for 66% of domestic energy consumption. 75% of dwellings alreadyoccupied will still be in use by 2050 with new dwellings only adding 1% per year toexisting stock levels. The aim of this research is to develop a matrix by whichdecisions can be made to help decide on the best use of resources to reduce CO2emissions for different types and ages of dwellings in Northern Ireland.

To derive a constructional baseline of the dwellings in Northern Ireland, thebackground calculations used to generate all lodged EPCs undertaken to date wereobtained and analysed as part of this research. The SPSS Statistics programme wasused to recode and extract all the EPC construction data. Floor plans of dwellingsbuilt from pre 1919 to date were obtained from Building Control. IES (Ve) was thenused to dynamically simulate the performance of the dwellings and the effect ofsubsequent possible alterations to their thermal envelope. Costs were estimated fortheir refurbishment and replacement. A novel decision making matrix was thendeveloped to categorise each type / age of dwellings and determine what was the bestuse of resources i.e. retrofit energy saving features or demolish and rebuild thedwellings to reduce CO2 emissions.

Of 80 variations, 64% of emissions were generated from 13 dwelling types / ages. Tomake deep cut C 02 savings, most of these dwellings ought to be fully refurbishedrather than replaced. This research has highlighted that the indiscriminate and ad hocapproach to retrofit is not going to optimise CO2 reduction. There should be a focusplaced on the dwellings which can readily achieve deep cut emission savings andspecifically retrofitting features to achieve the best value for money

Date of Award	Oct 2014
Original language	English
Supervisor	Philip Griffiths (Supervisor) & Trevor Hyde (Supervisor)