If you wish to build a Conservatory with an eaved roof, first construct a building with square corners. Add the transparent floor tiles.

The floor tile is distributed with kind permission of Caro's Sim Kagen.

Add an extra row of floor tiles around the outside.

 

Note: Because you can't see the tiles, it is easy to forget they are there if you later decide to remove or edit the building.
Each corner is make up of two pieces.
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Add the pairs of corner pieces.
Complete the sides with the straight roof piece.
Add as many flat roof pieces as you need to keep out the rain.
Why not use the roof pieces as cloches to build a cold frame for your tender plants.