This week another home came on the market with a 'locked' room. The MLS showing instructions said; "show the house and if your clients like it, the listing agent will make arrangements to have the 'locked' room shown". There was no other explanation.
This is a family home (I did a drive by), not the type of home that would have a 'grow' room or a drug lab.
I find it difficult to believe that the owners and the listing agent believe that buyers would make a second trip to the home to see one room.
If you will be placing your home on the market in the future, the concept of having a room, any room, locked; does not work. If necessary relocate what ever will be in a 'locked' room to a storage area. Out of sight, out of mind.
Home-buyers want to see the entire home! If they like it they may decide to write an offer immediately. You do not want them to wait to see a 'missing' room! There is too much competition out there right now.