THE MCMANSION IS dead! Long live the Jewel Box! Or so the housing industry tea leaves read to those looking beyond the next gated community. Whether driven by rising construction costs, shrinking lot sizes, increased urban infill, or aging baby boomers demanding high style in smaller footprints, the average size of a new home is holding steady at 2,400 square feet ... and is expected to pretty much stay there through the next decade.

Sure, you can still find houses resembling resorts in their footage and features, but for the masses, builders must think outside (and build inside) the box to squeeze every inch of function out of the average-size floor plan. “Using space efficiently is critically important to buyers and builders,” says Barry Glantz, president of Glantz and Associates Architects in St. Louis. “I've never had a client tell me to waste space.”

Maybe not, but there's still plenty of unused (or at least underused) space in most floor plans if you look closely enough ... or are willing to concede a shift in your buyer's lifestyle needs. From separation walls and long hallways that impede through-views to the sacred formal dining room that collects more dust than holiday memories, traditional floor plans—especially those at or under the average square footage—are ripe for retooling to achieve a happy union of efficiency, function, comfort, and value.

Understanding and applying proper spatial relationships, proportion, and other design truisms is second nature to residential architects, but typically less so for home builders. “As architects, we strive for space efficiency in every plan, no matter the footage,” says Gary Godden, president of Godden|Sudik Architects in Centennial, Colo. “Builders sometimes don't understand how multiuse spaces and proportion work as a function of square footage to create an efficient floor plan.”

Translation: Making an average-size or smaller house as efficient and functional as possible isn't complicated, but it does take some thought—and sometimes a leap of faith in the market. “We challenge some of our builders about whether their buyers really use the living room and how they use it,” says Jeffrey Lake, senior principal with Bassenian Lagoni Architects in Newport Beach, Calif. “Typically, it's underutilized and not how people live today, so we often downsize it into a parlor and offer it as more flexible-use space.”

Lake also advises builders to simplify if they want to make a smaller home live larger. “When you try to provide something for everyone instead of coming up with a targeted program, it cripples the floor plan,” he says. “If you're trying to put two bedrooms and all the common spaces down, that's just too many pieces in the puzzle, and it makes the house look smaller.”

Knowing and respecting how buyers truly use their homes, and even differences among generations or stages of life (think retirees versus young families), dictates how the floor plan comes together. “One of our first considerations is the buyer profile,” says Erin O'Leary Barker, design director/ associate in the Tampa, Fla., office of Des Moines, Iowa–based Bloodgood Sharp Buster Architects & Planners. “Younger buyers and families need quick and easy access to things, so we design more transitional spaces.” Older buyers, meanwhile, tend to accept and want more-defined areas, she says.

The “hit-and-run” lifestyles of today's younger buyers, says Barker, demands (and allows) architects and builders to reallocate underutilized areas of a traditional floor plan to create space that these buyers appreciate. “They want built-ins and places for the phone charger, coats, and keys before they get into defined spaces” such as bedrooms, she says. “They don't care how it looks, [as opposed to older buyers, who tend to like things tidier and shut from view,] as long as it gives them quick and easy access to their things.”

She also warns against trying to use or create niches for specific functions at the expense of not only a more open (and thus perceptually larger) floor plan, but also the kind of communal spaces that today's buyers crave. “For young families, the time spent together is few and far between, so ... they want a large gathering area,” says Barker, who suggests reallocating the footage taken by a computer niche in the hallway or a bedroom.

Though they may be somewhat trendy, creating transitional spaces such as drop-off zones just inside the door to the garage or foyers that glimpse living spaces or the outdoors from their sides as well as straight ahead (a trademark of Lake's floor plans) aren't trickery. “Space-efficient design isn't trying to make a 10-foot-by-12-foot room feel big,” says Glantz. “It's providing a better level of design that feels and lives better.”

For those builders whose neighborhoods of 2,400-square-foot or smaller detached homes attract a mix of buyers, never fear: Among residential designers, efficiency and flexibility go hand in hand these days. “That fourth bedroom/den option should be a truly ‘extra' room for the buyers to do whatever they want,” says Barker: use as a card room or spa, showcase memorabilia, or pursue passions and hobbies ... and transform into a bedroom in a heartbeat, if needed. “It becomes the true personal room of the house, which delivers the perception of luxury and customization.”

In addition to reworking the floor plan, architects seek the outdoors and views to it through the house to expand and extend the footprint (or at least the perception of it). They also look to provide memory or focal points to reinforce that feeling and deliver just enough drama to achieve the wow factor without wasting space. “We're seeing home buyers question the sense of heating and cooling a two-story-high family room with a wall of windows,” says Glantz, who instead suggests a one-story space with a flat, 12-foot plate height, using the “roof room” above it as bonus space. “It's not gimmicky. It adds real value and gives the builder some flexibility.”

Design pros also think about the size and placement of furnishings to improve and define circulation through the plan. “When you remove walls between rooms in a smaller house [to open up through-views and share square footage], circulation areas are defined by the furniture,” says Jerold Axelrod, principal of Axelrod & Cherveny Architects in Commack, N.Y. “Our credo is that you furnish the house in the design phase, not after the fact.”

There are, of course, products to expand space even more, including a variety of customizable and modular garage and closet storage systems, full-height telescoing and accordion-fold walls of windows and doors, and even insulation and controlled ventilation products that help create semi-conditioned attic and crawl spaces to accommodate storage needs and mechanical equipment that would otherwise eat up livable footage. “Found space is so important to smaller homes,” says Carol Lavender, president of Lavender Design Group, in San Antonio.

And maybe to all homes, as buyers trend toward a different take on housing's value. “Maybe housing isn't a commodity for resale or to just make a great first impression,” says Glantz, who senses consumers tiring of the big box trend and 600-square-foot master bedrooms that are impossible to furnish. “Buyers want something comfortable to live in that suits their lifestyle.”

SPACE-EXPANDING PRODUCTS

Though rarely called out on the plans or provided as standard on a builder's spec sheet, a variety of products expand closet, garage, and pantry/kitchen storage, eliminate wasteful door swing clearances, and otherwise find precious inches and feet that can be allocated elsewhere and for greater impact. There are, of course, extremes: While retractable furniture may not be mainstream, it's already in modern minivans. Can the suburban home be far behind?

SUBTLE DEFINITIONSTo open up the floor plan and create the perception of a larger space, tear down separation walls and lessen the number and length of hallways between and connecting common rooms in favor of wide, arched openings, columns, furniture, and floor and ceiling treatments to differentiate functions within a large communal space. “The transition between spaces ... is a function of how livable a house is,” says architect Barry Glantz.

LOOK UPBut not too far ... . Consider lowering the plate height of that peaked, two-story window wall to a 12-foot to 14-foot flat ceiling, then offer the space above it—without changing the roof plane—for conditioned storage, mechanicals and duct runs (per ever-stringent code mandates), or other bonus space. With that, push closet ceilings as high as possible. So-called “roof rooms” within the footprint of the house, as well as their traditional (if often unconditioned) placement over the garage, accommodate the increasing need for long-term and seasonal storage and squeeze every inch out of the plan.

REALLOCATE SPACEEven if you can't completely eliminate neglected rooms such as living and dining rooms, the plan can take a few feet from them and place it where it's better (and more often) used. A “family foyer” between the house and the garage provides a drop zone for a variety of modern communication devices, coats, and coins where it's most logical. “It doesn't have to be big, just functional,” says architect Barry Glantz. Look for similar transitional areas near bedrooms, and think about boosting the size of secondary bedrooms (and their closets) with footage from elsewhere in the plan to create more value and livability.

CREATE OPTIONSA gated or shielded motor court easily doubles as a safe play area or sport court, a selling point especially to young families. Similarly, a tandem spot in a three-car garage doesn't have to be just for vehicles: Tell (or show) buyers how it can be converted to a shop or storage area, an optional bedroom, or a flex space, or how it can be used to expand the footage of adjacent rooms inside. “Let the buyer make the decision on what to sacrifice and how to option those choices,” says designer Carol Lavender.

FURNISH FIRSTIn a small plan, circulation areas are defined by furniture placements instead of partition walls, says architect Jerold Axelrod, so take time during the design phase to analyze furniture groupings—based on a realistic number and size of pieces for the target buyer, and place them in the plan. The exercise is especially important to accommodate larger window expanses. It also will help to provide at least two furnishable walls in every room. “Besides,” says architect Barry Glantz, “smaller spaces are easier to furnish than a 20-foot-by-30-foot master bedroom.”

OUTDOOR INTRODUCTIONSEven just a glimpse of an outdoor space, and especially the natural light it brings into the floor plan, makes an impact on a buyer's perception of space and comfort. If the lot, budget, and/or climate prevent a massive outdoor area that shares or expands the footage and function of an indoor space (think outdoor kitchen or dining area), simply create through-views using wall cutouts and interior transoms, long sightlines from the entry to the back of the house, and small windows—in proportion—that provide a hint of what's outside. Shared courtyards, rooftop terraces, and step-out balconies provide other solutions. “Just seeing the outdoors, with some green space beyond it, is imperative,” says designer Erin O'Leary Barker.

GARAGE WORKSGarages are getting tight with behemoth vehicles ... assuming the cars can even fit in at all in deference to yard and gardening tools, sports equipment, seasonal items, and other junk dumped there. New systems reduce the clutter with myriad modular, wall-hung, and mobile cabinets, bins, hooks, and hangers that can be reset or replaced as needs change.

CUSTOM CLOSETSAs with garage storage systems, those designed for closets are both modular and customizable, allowing buyers to design a system that suits them now and then swap out components as their needs change.

SWING LOWWindow walls and doors that fold up against or pocket into the wall remove the need to provide swing clearances while providing a wide-open view of and access to the outdoors. With today's high-performance insulated products, thermal loss is no longer as big a concern.

STOWAND GOFurniture that retracts into the floor or wall and partitions that wheel away or into different positions are the ultimate in flexibility, if a little out there for most mainstream builders and buyers. The concept, though, is sound: Getting multiple functions out of the square footage is critical to an efficient floor plan.