When Patrick Planeta of Boston-based Planeta Design Group designs a model unit in a newly built residential property, he knows how to focus attention on the features the developer wants to shine and minimize potential stumbling blocks.

“I find that a well-done design should feel like a great party . . . all the details have been carefully considered,’’ said Planeta, who recently completed three model apartments at Watermark Seaport. “Though not immediately recognized at the time, it is vivid in your mind for days.’’

While model units function as practical tools to showcase finish options and offer suggestions for furniture layouts (“Everyone wants an open concept, but when they stand in the empty space they are overwhelmed,’’ said Ken Smith of Gibson Sotheby’s International Realty in the South End), they also sell a lifestyle. At Newport Beach Club, an oceanfront community in Portsmouth, R.I., the Radiance Beach House model evokes a luxury vacation atmosphere. It should. They spent $250,000 outfitting it.

It comes down to capitalizing on how people want to live. Andrew Terrat, regional visual director for Mitchell Gold + Bob Williams, who furnished models at Allele in South Boston, said it’s about understanding how people see themselves. “Often people move into these types of places because they’re seeking something totally different than what they have,’’ Terrat said.

How does a designer intuit customers’ real estate reveries? In the case of the Radiance model design (by Ally Coulter of Greenwich, Conn.), David Tufts, president of The Marketing Directors, explains that they devised a profile of the target buyer, including preferred pet (golden retriever), collection (sea glass), and leisure activity (paddle boarding). “The paddle board in the mudroom is a subliminal message that people can have an active lifestyle here,’’ Tufts said.

Dominique Sampson, vice president of sales and marketing at The Green Company, creates a fictional character for each model’s scheme, thinking about everything that person would like down to the type of plants. For a model at The Pinehills in Plymouth, Sampson imagined the occupant to be an event planner and set up the home office with a mannequin dressed in a bridal gown and her own kids’ wedding photos.

Such constructs are referred to in the industry as “memory points’’ — those wow moments that become etched in customers’ minds. It might be a simple cue that tugs at an emotion, like the bow tie Terrat draped over a lamp in a model apartment at Troy Boston. “It tells a story and makes people giggle,’’ he said. Or it might just be a notable design element, like a bright accent color, a shiplap wall, or a distinctive piece of furniture.

While models must be memorable, designers can’t go rogue. They must balance practicality with creativity and be sure the décor doesn’t overshadow the unit as a whole. “The goal is to sell the home, so I have to complement the space, not show off my interior design skills,’’ said Chelsi Christensen of North Hampton, N.H.-based Design East Interiors, who has designed models at The Pinehills. “Too many designers do not pay attention to scale and overwhelm the buyers with too many over-the-top details.’’

In suburban communities wooing empty nesters, model homes tend to embody a transitional style, boasting nautical, farmhouse, and nature-related themes. “I might pair white kitchen cabinetry with a dark brown island base and oil-rubbed bronze hardware, but I’m never going to do navy blue cabinets with brass faucets and open shelving,’’ Sampson said. A sliding barn door, however, is an easy sell anywhere.

In urban environments, designs might be edgier and trends more pronounced. When considering the lobby, model unit, and common areas at Millbrook Lofts in Somerville, Cheryl and Jeffrey Katz of Boston’s C&J Katz Studio worked closely with developer and owner Berkeley Investments to respect the building’s industrial vibe. In this former cold storage facility, the spaces have high ceilings, exposed ductwork, and raw concrete columns. “We imagined the customer to be creative and daring,’’ Cheryl Katz said. They also knew it would be important to warm up the spaces with upholstered furnishings, artwork, and plants.

Models are crucial sales tools in today’s post-recession building boom. Eric Ekman, senior vice president of development at Berkeley, points to the abundance of housing options as one reason. “People have less time,’’ Geraldine Joseph, who designs model homes at Cape Arundel Cottage Preserve in Maine, said. “Models minimize the stress of choosing a home and setting it up.’’ The community’s developer and owner, Joseph Paolini of Framingham, even lets potential buyers spend the weekend in a model.

Some customers like a model’s look enough to buy it outright. “The model floor plans are the first to go,’’ said Jason Gomes, property manager at Watermark Seaport, “and the first thing they ask is if they can take it fully furnished.’’

Many designers, developers, and salespeople report that this is a common question, though the models aren’t always up for grabs. Before moving into his newly leased 410-square-foot studio at Watermark Seaport, Oliver Koester purchased some of the same pieces Planeta used.

Walid Dehni said his family fell in love with a Newport Beach Club model Ducks in a Row designed, so they bought the same configuration and hired the Newbury firm to decorate it almost identically. “They received all the furniture and decorated the house. We moved in the same day we closed. It doesn’t get easier than that,’’ Dehni said.

At the end of the day, customers want to know whether their furniture will fit and where they’re going to watch TV. We asked those in the know to respond to the most common questions:

How do I set up an open floor plan?

New construction often features open layouts, but most people are not adept at visualizing the potential of an empty space. Terrat sometimes uses a sectional sofa to divide the living and dining spaces. He also encourages people to float a sofa out from the wall, using the space behind it for another purpose, like a desk, to create a room within a room.

Where do I put the TV?

At Watermark Seaport, Planeta avoided putting the TV on the most obvious wall, which would have required orienting the furniture inward rather than toward the unit’s best feature, the view. In houses, designers opt to tuck the TV in a den. At Millbrook Lofts, the Katzes skipped it altogether because it was obvious where it would go, and they assumed that some of the occupants would rather stream shows on their computers.

Is there enough seating to entertain?

“We use sofas with three cushions rather than two because it gives the illusion of more places to sit,’’ said Leigh Flaherty, co-owner of Timeless Interiors & Gifts in Hamilton.

Can I bring my dining table?

Downsizing empty nesters do not want to abandon their formal dining table. “We like to show a table that seats ten,’’ Sampson said. Terrat concurred, saying that developers ask him to put as many chairs around the table as possible.

Can I fit a king-size bed and night stands in the bedroom?

For a model at Millbrook in which the space on either side of the bed was small, the Katzes used wall-mounted night stands to keep the room airy and uncluttered.

My bed is right next to the sofa; should I use a divider?

Anja Park of Somerville-based Anja Park Design designed two units at Millbrook Lofts. “The special openness of a small loft can get lost when tenants start thinking about separating traditional functional areas like living, eating, or sleeping with shelves or curtains. It defeats the nature of what a loft wants to be,’’ Park said.

Can I fit everything I need in a micro unit?

In Watermark Seaport’s smallest units, Planeta used multifunctional pieces, including a coffee table with a top that lifts to 30 inches high, a bed with drawers and bookshelves, and a tabletop attached to a wall that folds down with stools.

How do I hide the parking lot view?

Terrat suggests placing the sofa in front of the window to block the view of the pavement. “Top-down shades are also great in this situation,’’ Christensen said.

Marni Elyse Katz blogs about design at StyleCarrot.com. Send comments to Address@globe.com.