WIT Press

Cost-Benefit Analysis (CBA) of Sustainable Drainage Systems (SUDS) retrofit: a case study


Free (open access)


Volume 4 (2021), Issue 1



Page Range

14 - 24

Paper DOI



WIT Press


Oluwayemi A. Oladunjoye, David G. Proverbs, Beck Collins & Hong Xiao


The retrofit of Sustainable Drainage Systems (SuDS) has been applied successfully to properties to help mitigate future flooding and to deliver other benefits to properties, such as improvements in air and wa- ter quality, economic benefits and improved business reputation. However, the uptake of SuDS retrofit has been low due to a lack of understanding of the true costs and benefits and concerns about long-term maintenance. This study presents a cost-benefit analysis (CBA) of the monetary and non-monetary val- ues of SuDS retrofit in the context of an individual property, in this case, a leisure centre. A qualitative study was carried out comprising a series of interviews with stakeholders to the property, an analysis of documentary evidence and observations on the site. The findings demonstrate the importance of teamwork amongst the stakeholders during the decision-making process in helping to overcome many of the known challenges. The willingness to pay process is used to value the tangible and intangible benefits arising from the scheme. The installation would provide a net value to the client of well over £100,000 over a 10-year period versus the installation costs of £39,000 and the return on investment would be achieved in just 3 years. The findings highlight many of the apparent barriers that need to be overcome when installing retrofit schemes and clearly demonstrate the importance of the intangible benefits derived. It is recommended that these are given full consideration at the decision-making stage and in supporting the uptake of the retrofit of SuDS.


SuDS retrofit, flood, leisure centre, costs, benefits and maintenance.