In the world of fashion, Miu Miu is the less expensive sister to the high-end fashion label Prada. And that same sibling dynamic is manifesting itself in the realm of the stores’ retail design.

After 10 years, the SoHo location of Miu Miu was looking tired and out of step.

Earlier this year, the company founder and creative director Miuccia Prada, along with her husband and chief executive, Patrizio Bertelli, summoned their creative team to give the store facelift. The results are now open to the public. At the helm of the renovation was the Italian architect Roberto Baciocchi, who has helped cultivate Miu Miu’s visual identity for more than 25 years. His task: Create a space that would echo the brand’s sophisticated, modern mission, as well as cater to the fluctuating nature of the collections.

Since 1973, Mr. Baciocchi, who is based in Arezzo, Italy, has been a key player in commercial architecture and branding. Under his belt is work on such luxury Italian brands as La Porcellana Bianca (housewares), L’Emporio (leather goods), Granello (fashion) and Gruppo Anteprima (fashion).

Since his first Miu Miu boutique opened in 1982, Mr. Baciocchi has had exclusive creative jurisdiction over all of the brand’s store concepts, designing outposts in places as diverse as Aspen, Colo., and Waikiki, Hawaii. He also oversees design for stores, factories, and showrooms for both Prada and Miu Miu. In recent decades, Prada has evolved into an international fashion powerhouse, and in some ways has outgrown Mr. Baciocchi’s original clean, subdued aesthetic. It was a major shift for the brand that in 2001, Prada employed controversial Dutch architect Rem Koolhaas to design the $40 million Prada flagship store in SoHo. The renowned Swiss firm Herzog & de Meuron was called upon for the Tokyo flagship.

The philosophy behind Mr. Koolhaas’s Prada store is pure spectacle. It’s an elaborate show where mannequins have television sets for heads, and an undulating ramp resembling a halfpipe monopolizes the entire first floor. The renovated Miu Miu is also a place where art and fashion collide, but it is much more intimate and much more of — heaven forbid — a store. Mr. Baciocchi opted for shiny, high-quality fabrics and materials, whereas Mr. Koolhaas delighted in ostentation, exaggerated forms, and a serious “wow factor.”

In the Miu Miu boutique, Mr. Baciocchi reconfirms his chic and refined aesthetic. From the walls down to the accessory display cases, the store is swathed in a shimmering greenish-gold silk brocade fabric that can be swapped out according to the season. This novel feature grants the store extreme versatility and evokes Miu Miu’s theme of regeneration. Rigidity was a major problem plaguing the store’s previous incarnation. The classicizing brocade fabric, which dominates the space, is thoughtfully contrasted with small but effective doses of modern materials such as perforated steel and cast iron. These juxtapositions are intentionally dramatic and instantly noticeable, as is the space’s volume.

Upon entering the boutique, one senses the vast architectural volume — similar to a museum — that creates a sense of autonomy for the consumer and makes the merchandise easily visible. The space at once becomes a place where both fashion and art are displayed and rendered accessible. And similar to other boutiques that seek to combine fashion and art, there is an air of regality and sophistication permeating the air.

My walk through the Miu Miu boutique was an overwhelmingly private and civilized experience, much like visiting a quiet gallery where one can carefully inspect the art and wander around largely unbothered by the staff or the brazenness of the space itself, unlike at Prada. I interrupted my quiet observation to ask a sales clerk about a cubic zirconium-encrusted bracelet in one of the display cases. The self-assured gentleman graciously assisted me, gushing that the outlandish piece of costume jewelry, a far cry from the simple stainless steel watch I had on, was “very” me. Doubtful.

As for the wall displays, the merchandise was displayed as veritable art exhibits: Handbags here are displayed and lit with the same care and thoughtfulness that the Museum of Modern Art would take in displaying sculpture. The handbag displays flanking the entrance, for example, exhibit 40 handbags strategically staggered against brocade-covered walls. Circular recessed lighting fixtures, which emanate light from various rectangular strips of mirror found toward the back of the boutique, also elicit the feel of a modern art exhibit. And that’s what Mr. Baciocchi’s Miu Miu space is all about: modern and traditional views of art brought together seamlessly in the service of commerce and contemporary fashion.