In BCA-speak, for redevelopment of a landed, they have the terms A&A, Reconstruction, and New Erection.
But the architects/contractors use the term Rebuilding because an Erection may mean something pathological...not so nice to say to a lady owner "oh miss, we have an erection here"...
The difference between A&A and Reconstruction is the treatment of incremental GFAs, who can be the QP for the project etc etc. I can't be bothered with the detail because, in the situation of New Ereaction, there are all sorts of by-laws influencing the design of a house already. A&A, Reconstruction lagi more...
Oh, another thing is, some architects or constructors don't do A&A at all...too troublesome they said.