For John and Lynn McKinven, the realization they'd found their dream home really did sneak up on them because the house they built in Winnetka was never intended to be their fantasy dwelling. It just turned out that way.

The McKinvens’ living-room galleria is a study in light and simple contemporary form. All major furniture pieces are licensed reproductions of modern classics. The family room (pictured top of page) reflects the McKinvens’ penchant for color and whimsy, featuring a collection of antique radios John and Lynn have been accumulating for 20 years.

The McKinvens began five years ago transforming a rather nondescript 1948 brick two-story into a bright and colorful home that perfectly mirrors the mindset of this playful family of five. Little is sacred when it comes to this house: From the whimsical modern art and furniture decorating the airy rooms inside to the irreverent blocks of primary colors used to highlight the contemporary architecture outside, the McKinvens' home is serious about fun.

Lynn McKinven calls it the ideal party house. Neighborhood kids dubbed it the LEGO House. In the summer especially, the place teems with younger ones, who splash about in the swimming pool or frolic on the basketball court. Adults relish the dinner parties, where things really get going when the first wine-tipsy guest pops on one of the vintage hats displayed in the dining room. The rambling house has intimate corners for family togetherness, handles large crowds supremely well and has ample room for indulging in myriad hobbies, from cookie baking to furniture crafting. Some hosts light scented candles when company is coming over; Lynn McKinven flips on her commercial popcorn maker.

"If this house has one thing, it has a great sense of humor," Lynn says.

The LEGO House — "the kookiest house in Winnetka," according to Lynn — is, in the McKinvens' view, nothing more than a modern-day version of the colorful 1894 Victorian "painted lady" the couple restored in Evanston. That house they inhabited, along with several of the post-modern pieces they use today, for eight years. Twelve years ago, the McKinvens moved with their three children to Winnetka into a traditionally styled 1905 stucco house. They adored the location near Lake Michigan, and when the small house on the large wooded lot next door went for sale, the McKinvens leapt to buy it. They moved into their new purchase and began the slow process of adding on to the house's original "nucleus," as Lynn calls it.

"Before we began this huge undertaking, the very first thing we did was put in a pool," Lynn says. "We thought that would help keep our sanity." Then the couple, working with Evanston architect Susan O'Connor Creevy, considered how they wanted to live. "First and foremost, we made a list of the things and hobbies and interests that needed to be accommodated," John says.

Stage One was a garage, woodworking shop, exercise room and office/artist's studio for John, a corporate vice president with a penchant for painting. Stage Two was an addition off the front of the house and included the living room with 28-foot-high ceilings, an intimate dining room, second-floor master suite, foyer and open-air loggia, where the couple entertains on balmy evenings. Bedrooms for the children, ages 14 to 18, and a guest room were carved from existing upstairs bedrooms. Stage Three was the kitchen, which has an open floor plan with room for a dining table and fireplace, computer work station and huge island for projects by Lynn, who in a former life was a professional baker. The third phase also included a practical mudroom/pool house, changing area/dog room (for the family's two pugs) and a laundry room with space and storage for crafts and gift-wrapping.

The fresh white hues of the master bedroom are the perfect canvas for the brightly colored accessories that adorn it.

The overall design — inspired by the work of Italian architect Ettore Sottsass, a favorite of John's and Lynn's — is a whopping success, the pair says. "It brings together all our slightly disjointed activities in a fun way," John says. "Those colored boxes on the outside are an expression of all the different things going on inside." The striking residence might be considered out of place, or even shocking, on the leafy and reserved street, but as Lynn notes, the house is discreetly set back from the road. And besides, "There are no color police in Winnetka," she says. "People love this house. We can't be outside without someone walking or driving by and giving us the thumbs up."

Approaching the LEGO House, which has for its front garden a 64-plant vineyard (grape-growing being a hobby of John's), one would expect the Rubik's Cube look to continue on the interior. But not at the McKinvens'. Their walls are painted a serene white — "that's the irony of the house," John says. The white walls are used to show off the myriad collections, including vintage posters and radios, aforementioned old hats, miniature chairs and life-sized modern furniture. "Our stuff is our color inside," Lynn adds. "We didn't want it to be a place so full of color the eye can't rest."

Lynn has no compunction about mixing antiques into a contemporary interior, though most of the old pieces are also of sleek design. In the foyer, a 1930s Art Deco sideboard — an Evanston antiques shop purchase marking the couple's first wedding anniversary — is set below a modern reproduction of an unusual swing-arm mirror by 20th-century designer Eileen Gray. An Art Deco armoire offers storage in the master bedroom. A late-1800s oak table in the family room serves as a game center; nearby is a Victrola.

"I like bringing the warmth of old in with new," Lynn says. "We like a modern, streamlined look but we didn't want the cold interior usually associated with Minimalism." Other modern classics include a pair of Eileen Gray Bibendum chairs, which bring a royal blue punch to the mostly white and black living room. Black leather and chrome Ludwig Mies van der Rohe armchairs are situated around a glass-topped Le Corbusier dining table.

The McKinvens further softened what could have been sterile spaces by incorporating wood floors in the main living areas, cork floors in the kitchen, exposed-brick walls from the original house in the dining room, and plenty of windows with woodland views. "Every window looks out onto beautiful green," Lynn says. "The thing about this house that I can't stress enough is that once you're here, you'd never know you were in a Chicago suburb. You could be anywhere — yet you can still easily zip downtown. We don't need a weekend house because we have it all right here."

The house has plenty to look at, what with all the collections, but the rooms in no way appear cluttered, a case for the benefits of decorating editing — "There's nothing in this house we don't love," Lynn says — and clever display planning. To house the colorful 1930s and '40s Bakelite radios the McKinvens have been collecting for the past 20 years, they designed a black-stained built-in display case that surrounds a fireplace and flat-screen TV in the family room. Simple white shelving in the living room shows off white porcelain Rosenthal vases — an interesting effect against the white walls that is simultaneously graphic and subtle. The same concept, this time using white blocks, is used in the master bedroom to hold Lynn's quirky and colorful handbag collection. A vintage stainless-steel medicine cabinet on the first floor houses a group of miniature reproduction chairs.

The dining room features a vintage hat collection and exposed brick walls that were part of the original house.

"Serious" art is also highlighted throughout the LEGO House. Paintings by Charles Seliger, Tom James and Winnetka's own Lark MacPhail — along with John's work — adorn the walls. A 4 1/2-foot-high sculpture by New Orleans kinetic sculptor Lin Emery was a purchase from a dear friend and neighbor who had displayed the work outdoors. "We had secretly loved it for years," Lynn says. "When she told us she was moving and having a house sale, we asked about it — something we never would have done otherwise." The sculpture's weathered-aluminum moving parts (which as a whole resemble a bird) was restored to a shine and looked so fantastic the McKinvens didn't have the heart to move it back outside. The sculpture now holds court in the living room. Floating high overhead in that room's white gallery-like space is a colorful mobile; its primary red parts pick up the unexpected red paint Lynn chose for the window mullions. "I had the mobile for years without using it," Lynn says. "That's one of the arts to collecting — sometimes you don't know where you're going to put something when you buy it."

Even the downstairs powder room (take a look at the vintage rocketship gumball machine) showcases a collection. The family refers to it as the "marble bathroom" — not for its black-and-white marble floors but rather the toy marbles, saved by John and Lynn from their childhood, that line the baseboards and door frame. "Even though we are committed to Modernism and all its purity, our philosophy is that life is short and our home should be inviting and comfortable and fun," Lynn says.

The LEGO House is also huge. ("I never wanted a large house," Lynn insists. "Apparently we don't know how to judge size from blueprints.") And even with huge houses, storage can be a problem. The McKinvens planned ahead. Lynn, not surprisingly, gets into the holiday spirit no matter the holiday and has a closet dedicated solely to seasonal decorations. A home office/homework station in a kitchen corner efficiently holds computer and fax equipment and miscellaneous paperwork. The mudroom is tiled and has a line of bright red lockers that store assorted items including bathing suits and pet food. The children's bedrooms were each outfitted with a new closet and work space. Back downstairs, there is a closet devoted to Lynn's entertaining collection, which includes no less than 150 pieces of glassware and, in the kitchen, food is kept in a refrigerator-freezer combo that spans 6 feet.

Hobbies are an important part of the McKinvens' lives, and their house was designed to handle interests beyond collecting. John's studio at the back of the house is where he deals with corporate homework (as Lynn calls it), chills out listening to his album collection (yes, he has a turntable), and works on his art. The adjacent exercise room has a mirrored wall and a treadmill, exercise bike and other workout equipment.

The basement, with a big-screen TV and 14-foot-long sofa, is the ultimate teen hangout; the eldest son and his buddies are poker fiends, so the space is also furnished with a felt-topped poker table (built by father and son in the garage woodworking shop). In the kitchen, Lynn's two convection ovens and pair of professional mixers are put to use making her specialty cakes and chocolate chip cookies; the giant island has lots of room for baking projects and doubles as "buffet central" during informal gatherings. Telephone talk could be considered a pastime, so Lynn designed a British-inspired phone booth in a nook around the corner from the kitchen; cell phones and text-messaging, she ruefully notes, have rendered the booth pretty much obsolete.

Dubbed the LEGO House by neighborhood kids, the multi-colored exterior is “an expression of all the different things going on inside the house,” John says.

Herbs and vegetables (including sweet corn) are grown in a plot outside the kitchen window. The front yard vineyard is a result of John's grape-growing fascination, an interest he developed during trips to France. He ordered the vines — primarily a hybrid red variety — from upstate New York, and the entire family had a hand in their planting. The vines have taken off despite the bitter and somewhat shady conditions.

Having a vineyard in suburban Chicago is "pure stubbornness and folly," John says with a laugh, adding that so far the "wine from it is absolutely awful." But since the first harvest three years ago, when the McKinvens' "foot crushing" tradition began, the grapes have grown into a fun, all-ages family endeavor.

The McKinvens, who enjoy life from a base that holds all the amenities and charm and adventures of a summer camp compound, clearly didn't let any future resale value dictate their house's design. As Lynn says, "We designed it for what we love. We haven't regretted anything" — which perhaps is a perfect definition for the phrase "dream home."

And next on the LEGO House to-do list?

"I'd like to put an observatory on the roof," John says in all seriousness. "I'd like to expand the house up into the treetops to get nearer to the stars." Then our dreamer chuckles. "Well, we'll see. It's something to think about."