1. Dr. Sarah Ward Associate Research Fellow Centre for Water Systems University of Exeter Rainwater harvesting for the 21 st Century: Challenges & Opportunities The Future of Rainwater Harvesting in Buildings SCI, Belgrave Square, 23 rd February 2011

2. Overview Challenges Conflicting Messages Unclear Guidance Energy Consumption in Context Uncertainty on scale and skill Opportunities Assessing Receptivity/Acceptability Perceptions of Health and Safety Evidence for Water Saving Efficiency The Way Forward?

3. Challenge CfSH – RWH needed for L5/6 (80l/p/d) (DCLG, 2006) Latter only assesses Average Incremental Carbon Cost: Does not include wider environmental or socio-economic cost-benefits e.g. shadow price of water, stormwater attenuation (new research available), resilience, adaptability Uses ‘future scenarios’, but does not assess emerging retrofit gravity systems i.e. ‘future systems ’ Carefully consider ALL aspects before it’s ruled out! Conflicting Messages: RWH increases CO 2 footprint of buildings (EA/NHBC, 2010) Vs

4. Challenge Unclear guidance on water-energy trade-offs: RWH is not the only water-saving technology that can increase energy/carbon consumption Do we stop installing low water- high energy appliances?

5. Challenge Energy Consumption in Context: E = energy consumedCO 2 = carbon dioxide emitted Cost = cost of energy usedSM = Simple Method IM = Improved MethodM = MeasuredMains = mains water equivalent LCA = full embedded & operational impact * = Australian Study (domestic systems; Gardner et al., 2008) Innovation Centre RWH System, University of Exeter: < 0.1% of total building energy consumption

6. Challenge Uncertainty on scale and skill:  In the UK SMEs represent 99.1% of all enterprises, 59.4% of private sector employment and 50.1% of turnover – a lot of buildings/water use!  Interviews with SMEs: Non-implementers/Implementers; Retrofit/New Build Five Implementation Deficit Categories 1) Expertise and Advice 2) Guidance and Support 3) Visibility and Access 4) Confidence and Communication 5) Finance and Consultation “Needed to know so much about all this technical stuff, which was all too much, both time and stress-wise.” (Retrofit) “...feeling like the guinea pig…” (both) “The system is not well organised enough to support everything and you’re left to sort it out.” (New Build)

7. Why aren’t more SMEs engaging with SWM/RWH? Primary reason: complexity of process – information gathering, support and implementation

8. Opportunity Assessing Awareness: Receptivity ‘…don’t see it advertised; get solar panel things through the door, but not for water’. Broadclose (Bude) & Innovation Centre

9. Opportunity Assessing Awareness: Acceptability Having to pay for regular maintenance Having disruption to my home/life during installation Willingness to pay was less than estimated cost Broadclose & Innovation Centre

10. Opportunity Perceptions of Health and Safety: Innovation Centre System Microbiological Quality Building Design Features

11. Opportunity Perceptions of Health and Safety: Aside from misconnections, health risk is minimal

12. Opportunity Evidence of Water Saving Efficiency: Greater visibility of REAL data for REAL systems at DIFFERENT SCALES Innovation Centre System (i) ~£1500/year saving (ii) Capital PBP = 11 years (tank installed is oversized)

13. 21 st Century RWH: The Way Forward? Increase efficacy of RWH for UK stakeholders e.g. enhance technical relevance by developing new products Reliable, central, independent source of information required Increase stakeholder consultation and engagement activities A Clear Vision Innovation Research Partnerships

14. Conclusions Move beyond focus on current system configurations Consider financial, technical and social perspectives Use opportunities to innovate systems and implementation models to overcome trade-offs, challenges and obstacles Find a ‘vision’ for RWH in the UK fit for the 21 st century – provide a direction for ‘re-designing RWH’

15. Sarah Ward sw278@exeter.ac.uk Rainwater Harvesting for the 21 st Century: Challenges and Opportunities QUESTIONS? The Future of Rainwater Harvesting in Buildings SCI, Belgrave Square, 23 rd February 2011