Polycraft Dirt Warehouses
Figure 1 shows one possible footprint of a dirt house that can lead to a valid Warehousing structure that can support a Technology Level 1 population. The maximum outer footprint of a dirt house is 5 x 5, while the inner footprint is 3 x 3. This doesn't leave too much room for creativity in your civic engineering, now does it? Well, your design freedom will explode as your houses get bigger and taller and are made from better materials. Your robot population density will also increase.
Figure 2 shows a side view of a valid dirt house with a decent amenity score leading to a single happy Delivery Bot. Notice the windows, paintings, flowers and light level all factor into the Efficiency score for that Robot. Also note that 85% of the structure is made of dirt. Too many windows leads to a structure that cannot allow Polycraft World Delivery Bots to operate. Also beware of the mechanics around the door. Warehousing must use wooden doors. The doors must have a solid block frame (no glass around the frame). The door must also have an entry way that is empty. No torches on the first block inside your Warehousing structure. The entry block (or the ceiling block of the coordinate just inside the door must also be solid.