They go as high as they need, The prefer to build up than out but because the way their technology and economy works views and vistas are the primary consideration for building a city. Hioth Viol is actually the capital of the planet, It may be city five (Dilt) it was re-purposed. Quote Dodecahedron
Do Moltinians have skyscrapers or do they prefer urban sprawl? I might try drawing Hioth Viol.
The way Moltinians design buildings is architectural uniqueness, as Moltinians go for the best possible looking city each building has a uniqueness to it. Moltinian Cities also have their utilities sticking out as they are proud of their tech, Shield gens, Quonos Gens(Power gens) ect. But drawing a Moltinian city would be awesome, I've only had my imagination to picture the cities.