How can life cycle analysis inform retrofitting choices for ireland's existing housing stock?

Bryan Drury

Test Methods
Life Cycle Analysis
Case Study

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Tim O Leary
Olivia Golden

This study analyses the existing Irish housing stock, particularly those built between 1970 and 1980, and aims to discover an efficient method to retrofit a typical case study building to a higher BER.

This study assesses a typical existing dwelling's carbon output and the most efficient method to retrofit the building to a higher BER (Building Energy Rating) while keeping material sustainability as the focal point. It is hoped that an method of retrofitting Ireland's dwellings will be discovered throughout this study while also reducing the CO2 (Carbon Dioxide) output. The need in the Irish context for retrofitting older dwellings to achieve the carbon targets set out by the government and an opportunity to discover a sustainable and economical solution, along with a personal interest in sustainability, is my motivation for this dissertation. In addition, this research should encourage more sustainable retrofitting methods within the construction sector.

The methodology used in this study involved assessing an existing detached dwelling and generating a Revit model to develop an accurate material take-off of the building. Once the building was duplicated, several different retrofitting strategies implementing Expanded Polystyrene, Mineral Wool, Phenolic and Woodfiber Insulation were applied and run through a Life Cycle Analysis on OneClick. Each of the building methods achieve a BER of B2 and a wall u-value rating ranging from between 0.168 w/m²k to 0.176 w/m²k in line with restrictions set out in the Techniocal Guidence Document L.

The study results showed that when achieving a similar U-Value and BER rating, there are minimal discrepancies between the different materials in each strategy. Although the Woodfibre insulation method proved to be slightly more efficient, to achieve the target U-value and BER, the quantity of insulation (200mm) applied to the internal side of the wall proved to be un-reasonable to that of the Mineral Wool strategy (160mm) applied to the external side of the wall.

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