1. Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
2. Smith School of Enterprise and the Environment, University of Oxford, Oxford OX1 3QY, U.K.
3. FundiFix Limited, Nairobi 00200, Kenya
4. Department of Civil Engineering, University of Washington Tacoma, Tacoma, Washington 98402, United States
5. Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands