11. The Greenhouse Observatory
Two of my favourite builds in one. I put a glass greenhouse on the ground floor — wheat, flowers, glow berries hanging from the ceiling — and the observatory on top, with a spiral staircase connecting them. Warmth from the greenhouse rises up and keeps the viewing room cosy. The glass walls mean you can see the stars from the greenhouse too, and in the morning the whole thing fills with sunlight. It’s practical and pretty, which is a rare combo.