It would be pertinent that you should use architectural firms in Singapore that have been adequately registered. Prior to an architect being registered, they would be required to prove about them having the ability to offer the best services possible. Once you shortlist a few architectural firms, it would be good to visit them.
You should make an effort to visit the architectural firm and ask about the services offered by them. You would be required to know how long they have been in business along with the number of customers they have actually served. It would be serve your needs in the right manner.