The impe­tus for build­ings to decar­bonize and move towards rad­i­cal ener­gy and water

effi­cien­cy is increas­ing­ly strong and iden­ti­fied as a pri­or­i­ty with­in the green building

sec­tor. The tiny house move­ment offers an oppor­tu­ni­ty to both address the challenges

of afford­able hous­ing and con­tribute to res­i­den­tial build­ing decar­boniza­tion. Tiny

hous­es de-empha­size mass con­sump­tion and exces­sive belong­ings and have potential

to address equi­ty issues such as gen­tri­fi­ca­tion by pro­vid­ing liv­ing spaces to lowincome

res­i­dents in desir­able hous­ing loca­tions. This paper ana­lyzes the Tiny House

in My Back­yard (THIMBY) project, inves­ti­gat­ing build­ing sus­tain­abil­i­ty concepts

through the design-build-occu­py process in a three-year-old struc­ture. THIMBY

demon­strates ener­gy and water effi­cien­cy tech­nolo­gies inside an award-win­ning small

liv­ing space (18.5 m²). THIMBY was designed to reduce ener­gy and water use by 87

and 82% com­pared to Cal­i­for­nia res­i­den­tial aver­ages. In prac­tice, it has reduced site

ener­gy by 88% and has emit­ted 96% few­er car­bon emis­sions than a 2100 square foot

Cal­i­for­nia Ener­gy Com­mis­sion 2016 Title 24 min­i­mal­ly com­pli­ant home. We discuss

the dif­fer­ences between design and per­for­mance of ener­gy and water sys­tems, which

we find offer impor­tant lessons for the fur­ther expan­sion of the tiny house movement

and oth­er alter­na­tive and micro green hous­ing types. We find that opti­miz­ing such

hous­es through inte­gra­tion of ener­gy and water sav­ing tech­nolo­gies, home energy

man­age­ment sys­tems, and strong com­mu­ni­ca­tion between mod­el­ers, builders and

occu­pants will be essen­tial to achiev­ing dra­mat­ic ener­gy (87%), water (82%), and

car­bon (96%) savings.