What would a small city built to 10,000 year durability standards look like? It would be built of very permanent materials such as granite, which would be intentionally designed to be very difficult to modify for an alternate use. Therefore, buildings would look very chunky and utilitarian and be very utilitarian. The edges and corners would be rounded because sharp edges are easily broken. The walls would be thick and the larger structures would be dome shaped or arched gallerias and the windows to the outdoors would be relatively small and triple-paned with thick unbreakable glass. The walls would have glass fiber insulation fused to the granite walls both on the inside and the outside to minimize heating and cooling needs and over the insulation a layer of wear resistant tiles. These structures would be made relatively large to minimize the surface to volume ratio which makes it easier to maintain an even temperature. A number of gallerias could be made in parallel to form large interior spaces. What I have described is like some middle eastern mosques but not with columns but with much more solid walls between the galleries. The whole structure could be built with sufficient solidity to have a roof with soil a couple of feet thick, which could be used as a garden and park. This sounds like a car parking structure only more solidly built and of more permanent material than re-enforced concrete.
These structures would be similar to a large modern hotel but much wider and shorter and are intended for a complete community life but there needs to be many individual interior spaces which are high-ceilinged and spacious to maintain a healthy psyche. Lighting and ventilation for such an interior space must be overbuilt but they should be as near automatic with these functions as possible. Sunlight could be collected with mirrored outside walls and conducted throughout the building to the solar bulbs located in every room. The light could be distributed through the large air flow pipes which also need to go to every room. These are fed from a passive heat exchange system to the outside air with funnels to guide the air through the system when the wind is blowing. But this flow could be enhanced with a sun heatable chimney which would draw air through the pipes from convection up the chimney on sunny but windless days. A large heat sink would be built into the ventilation system to convert and store cold night air in a water pond on hot days and the reverse in the winter with the storing of the heat of sunlight. These functions could be controlled with automatic valves. There would be supplemental electric lighting which in the night would be derived from batteries which were charged with sun driven electricity during the day. Pressurizing air is an efficient way to store energy also.
This is a sketch of a distant community forced to live underground because of our modern destruction of our environment.