NEW YORK • Washington and secrets go together hand in glove.
It should be no surprise then that the area is one of the hot spots energising a growing demand among American home owners for secret doors - panels, bookcases, mirrors or artwork - that swing open to reveal a passage to another room.
And as pre-built, ready-to-install doors become more widely available, people are adding them for aesthetics and, for those living in small condominiums, practicality.
For Ms Nicole Buell, a bookcase that concealed a doorway solved a design problem.
In her 540 sq ft condo, the doors to the only bathroom were in her bedroom and living area.
The living-area door left too little room for pictures or bookcases.
"It just wasn't a good use of space," said Ms Buell. Walling over the door was an option, "but I didn't want guests to have to go through the bedroom to get to the bathroom".
The solution began with door hinges bought from Secret Doorways. With the help of her father, she constructed shelves and mounted them on the ball bearing hinges to create a bookcase that swings open to reveal the loo.
"It's fun to surprise my guests when they visit," she said.
Now, secret doors are going mainstream.
Mr Jeff Watchko, interior door buyer for Home Depot, said: "It has become more of a trend than we expected."
Three years ago, the company began to offer, online, pre-hung bookcase-doors from Murphy Door in Ogden, Utah.
Mr Watchko said the popularity of the secret doors - which range from US$850 (S$1,160) to US$1,750, depending on size and finish - has prompted Home Depot to introduce displays of them in several cities.
Mr Victor Brown, a real estate agent and a home appraiser with Capital Market Appraisal, said mentioning a hidden door in advertisements could attract more traffic to an open house.
"Indirectly, it might help you get a higher value because you are getting more people interested, which might drive the price up," he noted.
There are people who want something more elaborate than a swinging bookcase.
For them, there are companies such as Creative Home Engineering in Gilbert, Arizona. Founded by Mr Steven Humble, it often designs doors of unusual size and complexity. The options include a mirror that hides a safe room and an entry large enough to drive a vehicle through.
Because the doors are on the pricier side - a mirror panel starts at US$1,500 - a smaller proportion of Mr Humble's customers are buying for aesthetics alone. "I'm going to say 75 to 80 per cent have a security purpose in mind," he said.
Mr Daren Rubenstein, a director at luxury hotel Jefferson in Washington, is another fan of hidden doors, installing a massive mirror that swings away to reveal a closet in Room 410.
He researched hidden doors online and hired Creative Home Engineering because of the fit-and-finish requirements of the product.
"If you didn't know there was a secret door in the room, it would take quite a while to figure it out," he said.
In fact, the year-old novelty installation has been a bit of a problem for that very reason. The staff do not always remember to alert guests to the door's existence.
"A lot of times, the guest can't find the closet," Mr Rubenstein said, which leads to a call to the front desk. "When they find it," he said, "they love it."