Kith Regent Street reads the building before adding anything to it.

Stand at the entrance to Kith's new London flagship and the first thing you look through is a pair of original curved glazing panes about a century old. The vestibule survives from the building's 1920s Neo-Baroque rebuild of John Nash's early-nineteenth-century Regent Street plan.

The project

Nothing on the street-facing elevation has been touched. Everything that makes the project architectural lives on the other side of the glass.

Kith opened at 314 Regent Street on 28 November 2025 — the brand’s first UK standalone, consolidating two adjacent units formerly numbered 318 and 324 into a single two-floor destination on the corner of Regent and Little Portland Streets. Ronnie’s, founder Ronnie Fieg’s first independent restaurant, took a separate entrance at 324a and opened two weeks later, on 12 December. The building is Grade II listed and sits within The Crown Estate’s Regent Street portfolio — the entire 2km street held by one landlord under one conservation framework. A reported 19,000 sq ft across two floors; the figure is consistent across BoF, WWD and Surface but isn’t on Kith’s own channels.

The architect is Porto Architecture, the Brooklyn practice Ben Porto founded in 2020 after a six-year tenure as partner at Snarkitecture. Porto has designed every Kith flagship since, working to Fieg’s creative direction. No UK architect of record has been publicly named.

Context

Kith has been in the UK since April 2019 via a 700 sq ft shop-in-shop in Selfridges’ Designer Street Room. Fieg told BoF that footprint became “a pretty significant business” for the brand’s e-commerce, but it was a visibility play — not an architectural one. The standalone conversation started when the Regent Street building became available. Fieg to Highsnobiety: “I wanted to wait until we found the perfect space. When the building on Regent St. became available, I knew we had found our home.”

That’s the brand story. The strategic story is about register. Kith has been shifting its retail programme toward what Fieg calls elevation — a word he uses himself. The Paris flagship in 2021 put Sadelle’s inside a glass-covered courtyard. The September 2025 launch of Kith Ivy in New York’s West Village — a members’ wellness and padel club with a $36,000 initiation fee, a Giorgio Armani spa and the first Erewhon tonic bar outside Los Angeles — moved Kith into a register that isn’t streetwear and isn’t quite luxury either. London was designed in parallel with Ivy. Fieg, to BoF: “there’s some crossover there [with Kith Ivy] in materiality and how regal the space needs to feel.” The word that keeps coming back across his public statements around London is “elevated.” To Highsnobiety: “The London flagship may be our most elevated space yet.”

The Issue 01 argument sits around this. The 2025-26 material-architecture reset has been concentrated in APAC — the Sanlitun corridor in Beijing, Jing’an in Shanghai, material arguments written onto luxury-retail elevations because the Chinese market rewarded architectural statements. London is what the same argument looks like when the elevation is legally frozen. The Grade II listing doesn’t let the material move to the street. It has to go inside.

The design

The plan reads as a sequence, not an open floor plate. Walk in and the brand uses the existing vestibule as a tonal datum — curved glass, original mouldings — and holds it unchanged. New fixtures are calibrated against it.

Either side of the threshold sits a paired room. Kith Kids occupies one flank, Kith Treats the other, unified by a custom fan mosaic that appears in both and nowhere else. Kids is the brighter of the two: Estremoz marble for a central bench, cloud-like lamps, a cloud-motif ceiling, satin brass accents, Kith monogramming throughout. Treats takes the same fan mosaic against a muted pastel palette — Rosa Portugalo and Azul Cielo marbles, Volakas marble counters, stainless-steel trim, classic bar-style seating. The flanking rooms handle two different audiences and read as a matched pair tonally distinct from the retail core behind them.

Past the threshold, the plan opens into Kith Women — the lightest of the three primary rooms. Custom white oak millwork inlaid with Crystal Tiffany marble forms the fixtures. Estremoz marble lines the walls. A Pentelikon marble band and inlay run the floor, laid as oak herringbone. The treatment aligns directly with the Chicago and New York Women’s builds. Kith’s own blog calls it “reminiscent of recent Kith Women builds in Chicago and New York City” — this is continuity, not reinvention.

Through checkout, the palette compresses. Walnut replaces white oak. Belvedere marble walls replace Estremoz. Calacatta Vagli marble tables anchor the floor. The herringbone deepens to dark-stained wood. Diamond-tufted green velvet and Kith-embossed leatherwork handle the soft finishes. Plaster moulded ceilings with recessed lighting complete the register — and this is where Fieg’s sharpest design move sits. To Dezeen: “Existing elements like the ceiling gave us the opportunity to design into the foundation in a way that makes it feel like we’ve always been there. Incorporating our K&K crest into the ceiling and adding brass inlays along the moulding are examples of how we were able to weave our DNA into the space in a cohesive and seamless way.” Kith’s chief web officer Dan Elmoznino told BoF during a walk-through that this is the brand’s largest dedicated men’s space globally.

The principal stair anchors the Women’s zone and leads down. A single named marble — Calacatta Fantastico Arni — with satin brass handrail and detailing. Kith Crest artwork meets the visitor at the lower threshold. The stair is the project’s signature architectural move: a continuous piece of stone furniture that carries the material conversation downstairs without shifting register.

The lower level continues the men’s palette at a deeper tone. Belvedere marble forms display cases and benches. A Calacatta Fantastico Arni band traces the perimeter of dark-stained oak flooring. Brass parquet inlay and K&K embossed velvet wall panels introduce warmth and acoustic damping. Footwear and luxury vintage sit here, and so does a McIntosh-powered listening room — four MC611 monoblock amplifiers, a C55 preamplifier, a DS200 streaming DAC, dual MT5 turntables, two XRT1.1K loudspeakers, each unit carrying custom Kith and Kith Records branding. Fieg told Highsnobiety that the audio system arrived after the architectural design was complete, and that he redesigned the lower level around it. That’s a mid-programme scope change, visible in the plan.

Nine named marble varieties across one build. Three timber registers. A single-marble signature stair. The material density is the argument — and it lives entirely inside the listed shell.

Ronnie’s sits next door and reads differently. Separate entrance at 324a, cocktail lounge with vintage-style barstools in red leather, dark wood-panelled main dining room, family-style booths under a gallery of black-and-white New York photography, takeaway café and outdoor seating. Dezeen reports red marble and fabric paired with dark wood; the specific marble variety isn’t named in any primary source. The programme took two years, per Fieg to BoF.

The build and the cost read

No primary-source cost or programme figures have been published. What follows is estimation with reasoning shown.

Upper Regent Street sits in the Crown Estate’s most expensive retail tier — indicative Zone A rents on this stretch are in the region of £600-900 per square foot, per market-comparable 2024-25 CBRE and Savills reporting. For a 19,000 sq ft unit the lease commitment alone runs into eight figures over term, before fit-out.

The fit-out specification is heavy. Nine named marbles sourced and installed at flagship quality. Custom millwork in white oak and walnut across two floors. A signature stair that is its own cost centre. A custom fan mosaic in two rooms. Brass parquet inlay. A reference-grade McIntosh audio system with custom branding plus the acoustic treatment to support it. K&K embossed velvet wall panels. Diamond-tufted green velvet upholstery. Plaster moulded ceilings with recessed lighting and integrated brass inlays carrying brand marks. The restaurant programme at Ronnie’s is a separate cost line — commercial kitchen, bar, FF&E, MEP load distinct from retail. Listed-building specialist trades for the interface with the historic vestibule and the retained 1920s fabric carry a 10-15% premium on design fees and programme against a non-listed equivalent.

Triangulating against publicly-disclosed comparable fit-outs — On Running’s 2023 Regent Street flagship, Hunter’s global flagship on the same street — the likely range is £5m-£8m fit-out, weighted toward the upper end given the restaurant programme and material density. Programme likely ran 14-18 weeks on-site preceded by 6-9 months of design and Westminster City Council listed-building consent; total programme from commencement of design to retail opening likely 18-24 months. The McIntosh redesign Fieg described would have driven a mid-programme change order — visible in the final plan, not visible in the delivery schedule, which hit 28 November on the nose. Ronnie’s slipped two weeks, which is standard for restaurant commissioning.

No indicators of value-engineering in the published coverage. No indicators of cost overrun. Kith is an independent brand — Fieg declined revenue discussion to BoF in November — and this capital is deployed from the brand’s own balance sheet, not a luxury group’s.