Several of my clients are smaller employers in the 75 -200 employee range. As such the HR department is more often than not housed in the suite of offices around the Executive Director. In some cases it is because in the early days of the organization the HR Director and Accounting Director were the same person. After the workforce and operation grew the roles were split but the office stayed the same. In some cases the roles are still combined.
The problem with this arrangement is that it is a gauntlet of management that an employee must run to get to HR. It is highly unlikely that the visit will be confidential, even if the door is closed. Part of the inhibition employees feel in coming to discuss concerns is that their boss will know that they came to HR about "something", and any visit could cause reprisals if the supervisor is of such disposition.
Another issue in HR offices is privacy due to the construction of the office itself. Often air ducts allow adjacent offices to hear the conversation. It is not uncommon in our line of work for nosey employees or supervisors to go to an adjacent office or stand outside the office door to hear what is being said.
To ensure confidentiality and privacy I recommend, from my own personal experience, the following:
1. Relocate the HR office to a place where there is no other management. Employees will feel more comfortable coming to discuss their concerns.
2. Run the duct work from the office into the open space above an open area such as a cubicle or production area. The noise from the office is disseminated into the crawl space and competes with other office noises.
3. Install weather stripping around the inside of the office door, and install a threshold. If the door has vents or glass, replace it with a solid door.
4. If walls are thin, install carpeted double-thick cork board as bulletin boards, starting three feet from the baseboard and extending to six feet above the baseboard. You can never have too much bulletin board space, you can hang pictures from it just like sheet rock if you like, and the conversations that occur both seated and standing will be muffled by the cork board and kept private from the adjacent office(s).
I have some some or all of this at different offices of my own HR departments. The total investment at the last one, Thomas Nelson, was about $300. It made several people feel better, and impressed with our commitment to their privacy, when they would look around the office before saying something sensitive and hear me say, "Don't worry, I've had the office sound proofed." Try it!