Building codes were regulations for how a structure was to be built or maintained.
In 2369, upon Quark's refusal to shut down Quark's for an extradition hearing regarding Jadzia Dax, Odo threatened him with enforcement of new building codes the Bajoran Provisional Government had enacted. Compliance with the codes would require the moving of a wall, which would necessitate dismantling his second level holosuites, and the bar, which was closer to the exit than allowed. Quark leveled an accusation of blackmail, but Odo assured him it was business. (DS9: "Dax")