Umseting - Enskt-Franskt - Conservatory

Please could someone help me with the French word for conservatory, in the sense of a sun room or indoor garden.
I preferably need the word as it would be used on a planning application or architectural drawing, rather than other everyday terms. Assuming there are alternatives.

Thank you for your help.

<Admin's remark>
This request is no longer acceptable according to our new submission rules.

"Conservatoire" for the "Academy" sense.
"Serre" for the "GReenhouse" sense.