Oh, that is not as simple as you say, there are no set standards or parameters to make a design actually a winning design....there are compatible and best designs as per the user/inhabitant and there are less compatable..

No, afaik there is no feature like this in Houzz app.

It might look easy, but it might be unfair to ask multiple designers to put in their efforts to design for free when it's not even a professional competition.

There might be some people who might just take these multiple customised designs for free and choose to walk away. 

Instead, as a suggestion you can have a look at designers profile and portfolio here and engage with them according to your convenience and taste.

Yes I get it, It is not as simple as I imagined... So naive of me to think such a thing could be possible...ὢ3
As you rightly said the BEST design varies from person to person, as per his/her individual requirements...