Sanosuke gets Building level scaling from being able to not get entirely fodderised by high tiers and fighting someone who could easily destroy a building in the Jinchu Arc iirc without any implied gains, so it's a stomp in Sanosuke's favour.
That was just a Wall or Small Building level feat. The only other feat of such impressive magnitude he had around the time was his leap to surpass Namu's requiring Small Building level energy, which is still a step behind Sanosuke's level.