The Built World
Erasure and enclosure is how you begin, every worldbuilding a worldbulldozing. The blueprint nascent in your imagination is not an exploration but a vision; the crumbling truth of the New Sodom Palladium, that grand ballroom long since turned gig venue long since gone to dereliction, is to be eradicated from the page, an imaginary edifice to replace it utterly. I rather liked that glorious ruin, having dossed there all my life as a bum, but your built world is to be built from scratch.
A great billboard on one corner promises utopia in shiny steel and glass, or perhaps a sandstone facade, golden as Byzantium but in one neat clean-lined block, not some guddle of back-alleys grown through centuries; corridors may seek to replicate the labyrinthine, cornices may seek to style the interior baroque -- the gargoyled grotesque of mock gothic even -- but your architecture and aesthetics are purposed ultimately to consistency. As a busker passing by on the interstitial streets of New Sodom, I see little of my city's intransigent chaos in the design. This is to be no Winchester House where one might open a random door to find a twenty foot drop through fresh air. No sudden exits to the outside here.
Over days, weeks, months, maybe years, schema becomes scaffolding, exoskeleton, steel bones of cartographic ossature your world will be built within, a framework of ersatz geography, history, science... of ersatz systemicity. There will be, for your built world, an a priori essence of How Things Are, and as bricks click into place, blocks lock together into bare walls mortared with desire, it is to reify that structural and structuring semiotics in stone and cement of text. Architects working, as the Victorians, from books of stock templates -- pages upon pages of door or window frame designs -- what rises is all too often built within a How Things Are that some of us have no place in. Consistency from the inside becomes conformity from the outside. Where there are no sudden exits to the outside, it is likely there are no entries for the abject. Worse, if there are entrances for the dogs of Sodom (Old and New,) they will be special entrances, just for us, where we must don our allotted tropic garb as servants or antagonists upon entry. Others entering through the foyer will find your built world awesome. Me, not so much.
Stability, security -- as we walk the inside of the built world, everywhere we see arguments for the authenticity of the ersatz. As visiting shareholders, we readers must be persuaded constantly, it seems, that the structure is sound, not just sturdy but of an inviolable integrity. The more girders are visible, the better. Even the worldbumphing of fake girders is good -- quotes from imaginary tomes as chapter epigraphs, a colonnade of pillars supporting nothing but signifying solidity. Your readers have their demands after all. Many may simply revel in their awe, gazing from the balconies that face inward to the wonders of the atrium, exotic flora potted round a fountain of Lethe water, but there are those who would clomp a foot on every floor, bang a fist on every wall, to test that solidity, the certainty. They stand on those balconies and rattle the balustrade: is this safe? If I lean on it, I won't fall through? If you begin in erasure and enclosure, you end in emphasis and entrenchment, every worldbuilding a worldbolstering: trust me, trust me, this fortress is invulnerable to doubt.
And in the end, completed to specifications, your built world stands as a battlemented bulwark, bastions on each corner from which denizens immersed to absolute conviction defend it loyally against insult. One cannot question the honesty of the ersatz, because it is the theoretical authenticity that matters; the built world is not meant to be relevant, only valid. The absence of windows looking out is featural, the poldering the very point indeed. The bastions are heights from which to scorn the barking of dogs outside: it's all just fun; if you don't like our world, go build your own.
I seldom find your built world somewhere I wish to stay.