ID is just ID (Interior Designer), most of them are not PM (Project Manager) so they know nut about HDB rules, they only know design design design; they are just good at showing you 3D picts and hard sell how "good" they are. If they are that good, word of mouth advert should give him enough projects, there is no need to do hard sell. I'm sure that ID bring you to the customer's place of a ongoing project and able to answer your questions on the spot, you will be sold instantly. Otherwise everything is BS. Some IDs are actually contractor themselves and maybe boss of the company, they started in this industry as contractor and later went through some short courses on interior design, do some nice nice 3D drawing and they start charging ID fee. This group cant tell you the diff between contemporary and minimalist. Most people will like them cos they are good at calculating fee and you will buy it when they help you save money on reno.