I have been told the odor is coming from my lavatory sink in the bathroom. THis is a brand new home and the odor is not going away. Every time I open the cabinet under the bathroom sink, the odor is stifling. Sometimes I smell it just when I walk in the bathroom. The builder said it was because only the top of the lavatory is sealed and not underneath. Is this normal? Could my smell be coming from the actual lavatory they installed? Frustrated in the bathroom with the odor and not being able to put things up- don't want everything to start smelling. I have tried putting baking soda, newspaper, strong air fresheners and nothing is working. Any clues?? Or could this be something else?

The Odor Is Coming From Your Sink Trap, Make Sure That You Do Have A Pea Trap Under Your Sink, The Purpose Of This Is To Keep Water At The Bottom Of The Trap Which Keeps Gases From Coming Back Up The Pipe,
If You Don't Have A Pea Trap There Is Your Problem,
If You Do Have One, Take The Trap Apart, Its Just A Few Plastic Nuts That Are Finger Tight, And Look Inside The Trap , There May Be Something In Side There Stinking It Up, If It Is A New Construction House There Is No Telling,
Ive Seen, Well Not Seen But Heard Of People Peeing Down The Pipes And Doing Other Things We Want Go Into. Lol.
So To Recap Start At The Trap Trie Putting Something In The Trap Like The Baking Soda, But It Needs To Be In The Trap Whatever You Do. The Cabnit Is Not The Problem,