We believe in children's rooms that don't need to be reoutfitted for each age and stage. Here's a playroom we think would work equally well for wee ones and for teens. Over the years, the stuffed animals will inevitably be replaced with books and electronics, but pretty much everything else will endure.
Below: Artemide's Tolomeo Classic Wall Lamp provides ambient and task lighting for those art projects that go into the evening hours. $278 at Lumens.
Below: Instead of buying a toddler-size chair you'll have to replace two years down the road, invest in a chair that your child can grown into. The classic Bertoia Side Chair (shown with a orange-carrot seat pad) is $545 at Design Within Reach. (NB: A limited number of child's size Bertoia chairs were manufactured by Knoll and can occasionally be spotted on eBay.)
Below: Made of hollow injection-molded polypropylene, the orange Cubitec Shelving is amazingly lightweight, strong, and versatile. $245 at Design Within Reach for a kit containing 18 panels (which can create up to six attached cubes). The configuration shown requires two kits.
Below: For floor seating, we like the affordable and portable One-Seater Beanbag in orange with a 100 percent cotton removable and washable cover ($39); or the Classic Bean Bag Chair in orange ($99); both from Land of Nod.
Below: Most child tables are only 18 inches high and are quickly outgrown, but often full-height ( 29-inch) dining tables are a bit of a reach. But with full-size chairs we still prefer the adult-size option. At $99, you won't mind when the solid wood Bjorkudden Table from Ikea gets covered in paint, crayons, and anything else kid crafts offer up.
Below L: I used Farrow & Ball's Borrowed Light with great success in my kid's playroom in London; it would work beautifully as a backdrop for the orange Cubit shelves. Below R: Benjamin Moore's Icy Blue is another good choice.