Adobe: Baked Dirt Bricks with the right waterproofing element can last near forever. Without the right waterproofing element casually last 200-500 years. Some of the adobe bricks on the Great Wall have properties equal to or in some cases better than modern concrete bricks.
Concrete: Simple, easy, and low tech one you have done all the development. Many buildings around prime ward (and second site and third site) are made of concrete.
Stone: You can't beat it for strength and durability. On Kerren, strength is the big consideration. You want to be able to hide in the building from megafauna, jumpers, and other such critters.
Wood: Used for supports and decorative elements. It is not strong enough to defend against most megafauna, so it tends not to be used for anything that a person might need to hide in. Yet many villages are mostly wooden villages.
Bamboo: This is not terrestial Bamboo, but it is bascially the same plant (Bamboo was on Terra long before the Dinosaurs, so a similar plant should develop on Kerren). It is used in place of wood for support and decorative elements.
Glass: A substance that the locals can casually make. With their knowledge of advanced technologies, they can make glass stronger than we can today with less technology. Windows are always small, and usually tinted or reflective to the outside. Why? Windows are the weakest part of the wall and if the critter sees you it will attack the window to get to you. Tinted or reflective glass prevents the critter for comming at you.
The Primary Digging Tool for larger constructs is Dragons. After all these critters dig caves out of cliff sides, they should be able to handle any dirt or stone. They are also the primary lifting tool.
Gips in harnesses can be a formidable pulling animal. Some wards are experimenting with domesticating other Saurians, with varying degrees of success.
Note: On Firstdown, Sitebee, Sitecee, there is biocrete. Bio-crete is a substance just being developed today. Throw a yeast, some biomass, and some warm water into a mold and a few days later... out pops a wall, a dome, or whatever. If they can keap a yeast starter alive, they can still be using this stuff. It was used to make some of the original buildings here. Those clusters have domes and sweeping buildings that can not be duplicated in other locations.