@Bandi Sruthi I confirmed that you will need to manually define your own manifest.json
file. CAD tools are what architects use to design buildings. Another way to create a map is to use MS Graph. A script would have to be written to output the manifest.json, so that is something you would have to write.
If you would like to make a feature request please do it in https://feedback.azure.com/forums/909172-azure-maps and share here so others can vote.
Thank you for your time!
PS: If I answered your question, please mark this as answer so others can find it easily.