At about 10 by 29 feet, the room becomes an obstacle course if so much as a pair of boots are dropped on the floor; at night, multiple chairs must be moved to make way for the fold-down Murphy bed. And because the bed rests on the dining table, failing to clear the dishes has dire consequences.

But this 295-square-foot apartment, which comes with more hidden storage and dual-function furniture than a space capsule, appeals to young professionals willing to trade size for the convenience of ­urban living. And in a city with little space to spare, it offers something rare: a downtown location for less than $2,000 a month.

“The size of the place is actually perfect,” said Terencia­ Tervalon, 32, an insurance executive who pays $1,600 a month for one of the 23 tiny apartments at 38 Harriet St. “I had five friends over the other night and we were all able to fit and have cocktails.”

Tervalon is the kind of young professional whom San Francisco, Boston, and other growing US cities are struggling to hold on to in an era of skyrocketing housing prices. As more people like her elect to live and work in urban downtowns, city officials are experimenting with construction of tiny­ dwelling units known as micro-apartments, in the process triggering a housing debate that is ricocheting around the country.

“If we don’t start producing enough housing, and the right kind of housing, then the affordability crisis in this city is going to be exacerbated,” said Scott Wiener, a city supervisor in San Francisco, where studios can rent for $2,500 a month and an influx of young technology workers is threatening to drive prices even higher. “We can either prepare for this growth or we can put our heads in the sand and pretend it’s not happening.”

On Monday, Mayor Thomas M. Menino of Boston announced a plan to add 30,000 housing units by 2020, saying the city must accelerate its housing production to meet the needs of young workers, middle-class families, and seniors.

Development of such small apartments is being promoted as part of the solution to the housing shortage in Boston and other cities. But there is unease among public officials about allowing real estate developers to flood the market with such units, out of fear they will become the modern equivalent of 19th century tenements. And with rents of $1,600 or more, many question their affordability and the willingness of people to pay big to live so small.

Even in San Francisco, officials have for now decided to cap the number of market-priced micro-units at 375, mainly because of concerns the city is skewing housing policy to help young professionals at the expense of families.

So far, the city is allowing developers to build units as small as 220 square feet, or about 25 percent smaller than Tervalon’s little apartment on Harriet Street.

In Boston, officials are also cautious. They have established a minimum of 350 square feet for micro-units and so far limit them to the developing South Boston Innovation District.

“We have plenty of people proposing to build these units because they see it as a lucrative form of development,” said Kairos Shen, Boston’s chief planner. “We don’t want to take away the incentives for them to build small, but we also want to make sure that we have real standards that guarantee a quality of life.”

In particular, Shen said, he wants to make sure that micro-apartment complexes have enough common spaces, such as lounges, to allow residents to stretch out beyond the confines of their tiny apartments.

“We are not seeing as much focus on those common spaces as we are on reducing the size of the units themselves,” Shen said. “And I think we have to pay attention to that.”

At 38 Harriet St., a four-story building in San Francisco’s fast-growing South of Market District, each unit has nine-foot ceilings and a bank of windows that fill the room with natural light. Space is tight, but every square foot is packed with conveniences. The sofa and refrigerator are full size; a combination washer-dryer is hidden in a cabinet. And although there isn’t a regular stove, the microwave (also hidden in a cabinet) has a convection feature for roasting a duck or baking a pie. Out back is a large patio framed by 10-foot bamboo plants.