Durasteel Reinforced Support Beams is a technology that can be researched at the Research Center in Tech Level 3. It costs 175 Food and 150 Ore, and gives buildings 10% more Hit Points and armor. It must be researched before Permacite Plating becomes available.
This technology is a useful addition, strengthening all the player's buildings, but not vital in any way.
"Not only does this Tech Level 3 technology boost your buildings' hit points, and makes them more heavily armoured as well."
—Manual description