The Setting: The basic setting consisted of foam core board, green poster paint, and light blue tissue paper (which the students requested). The foam core board ended up curling due to the paint. We didn't realize this would happen. The class is going to recreate their sustainable city this coming fall. We will follow the suggestions presented in https://www.lorenetroyer.com/how-to-keep-foam-board-from-warping/.
Trees and Bushes: I purchased a bag of trees and shrubs, e.g., see https://www.amazon.com/gp/product/B076Q1QJTL/?th=1. As was the case for many of the aspects for building this city, students ended up modifying them through adding pompoms to the trees to make fruit trees.
Paper Buildings: These were cut using a Cricut machine - see Paper Building Template. An alternative is to print a house template such as those found at https://www.template.net/business/paper-templates/paper-house-template/ and then cut them out. Students decorated them keeping in mind how the colors created a sustainable atmosphere.
Craft Supply Objects: I keep a generous supply of craft materials in my classroom that are on shelves for the students to use whenever or however they choose including: construction paper, craft sticks, pipe cleaners, pompoms, and markers. With these materials, they, from their own ideas, made bikes out of pipe cleaners and bike racks out of craft sticks. fruit stands out of pompoms and craft sticks, food transport carts, and farm animals and their pens out of pompoms and pipe cleaners
Toy Solar Panels: Solar panels such as the one found at https://www.amazon.com/Sunnytech-100ma-Module-Polysilicon-Charger/dp/B008J9BZIA/?th=1, were placed on the top of some of the buildings and used to light up LED light sources.
Chibitronic Light Stickers and Light Sensors: See these projects at Solar-Powered Chibitronic LED Stickers and Chibitronic Light Sensor.
Solar Powered Toys: One of the students mentioned that the sustainable city needed a windmill. I remembered that I had bought some 6-in-1 solar toys some time ago using monies from DonorsChoose. The students used those to build solar powered windmills and boats.
Laser Cut Greenhouses: Our school also has a laser cutter. Boxes were designed using MakerCase and the cut out of plexiglass. These were used as greeenhouses
3D Printed Animals: Our school has a 3D printer. Students located animal designs through Tinkcad and Thingiverse to print. These included sheep (see https://www.thingiverse.com/thing:95721), fish, chickens, and eggs.