A 120-year legacy: How a historic Song Wat building was reimagined for Restaurant Potong

Sojourn anchored the project around the philosophy of adaptive reuse, driven by two key concepts: "preservation" and "the future"—conserving the soul of the original building while introducing contemporary functions that feel wholly unified with its architecture.

This sensitive approach earned Potong (Phase 1) the Best Preservation Design 2024 accolade at the TIDA AWARDS, Thailand’s premier interior design honours. (The team felt immensely privileged to receive the royal trophy graciously bestowed by Her Royal Highness Princess Maha Chakri Sirindhorn).

To Sojourn, the century-old building stands as a testament to genuine sustainability. Constructed with deep pile foundations, solid masonry walls, and high-grade structural steel, its enduring framework has proven its resilience over 120 years.

Sojourn Design Studio began the project with the mindset of archaeologists approaching an excavation site. Exploring the building floor by floor alongside Khun Kim—Chef Pam’s father, who recalled his childhood days within these walls—the team mapped out the distinct historical layers left by the ancestors who built the original dispensary. The building’s true magic lay in this rich "layering of identities" across generations.

Reflecting on the design ethos, Jern explains: "A core part of our design approach was to express the presence of every generation that passed through here—from its days as a traditional pharmacy to its chapter as a wholesale merchant hub in Sampheng, just before Chef Pam took over. We wanted the architecture to feel like a portal through time, connecting guests with the memories embedded in the structure."

Concurrently, Chef Pam’s culinary identity of "Progressive Thai-Chinese" cuisine crystallised alongside Sojourn’s spatial vision. Sojourn translated her personal essence and family heritage into a nuanced design language—one that balances modern femininity, cultural roots, grace, and intensity—honouring original artworks created by Chef Pam’s own ancestor displayed on the exposed plaster walls, aligning seamlessly with her cooking style.

“The moment guests step inside, they are met with an unexpected sense of tranquility that feels worlds apart from the bustling street outside,” Jern reflects. “We preserved the original sign from the Potong pharmacy, the ornate plaster ventilation grilles, the timber beams, and the sweeping wooden ceiling. To evoke the experience of an old-world dispensary, we crafted new timber medicine cabinets and steel shelving to house herbal jars, keeping strictly to the proportions and spatial rhythms used by the original craftsmen.”

“We curated vintage medicine jars throughout the space and kept the original 'Industrial Green' paint on the collapsible steel gates—a relic from its warehouse era. To anchor this, we introduced 'black' as a defining counterpoint, giving the space a refined, contemporary edge. Pairing this green-and-black palette with the century-old timber ceiling, which we gently restored to uncover its original hand-carved details, created a striking contrast against the dark steel and stained timber grain.”

“Moving up to the main dining spaces on the second and third floors—the primary focus of Phase 2—our brief was to evolve the design and customer journey alongside Potong’s culinary growth. The main challenge was maintaining the beloved visual identity of the restaurant while striking the right balance between old and new,” Jern notes.

“The restored timber ceiling remains the focal point, steering the eye toward the balcony where stained-glass windows frame views of neighboring historic facades and tangled street wires. We carried over the green, black, and orange palette, but introduced deeper, more tactile orange tones using slubbed Thai silk hand-woven by local artisans from the Support Foundation at Bang Sai. A standout feature is the genuine gold motif painted onto silk screens by master Thai goldsmiths, honoring the precious materials historically favored in both Thai and Chinese crafts.”

“The wet-plaster walls, finished in what we call 'Shanghai Green', were smoothed to a soft, tactile texture that sets off the dark timber paneling. Another key addition is the bespoke carpet, designed specifically for Potong—a symbolic pattern that softens footsteps across the historic timber floors.”

“Along the Shanghai Green walls, natural light bounces off floor-to-ceiling mirrors that open up the narrow rooms. In Phase 2, we transformed these mirrors into expansive canvases, hand-painting delicate floral motifs across their surfaces—a nod to the porcelain mosaic details (crockery) on Wat Arun’s prang, an iconic Thai art form shaped by Chinese trade during the reign of King Rama III.”

Jern adds, “We added contemporary layers as subtly as possible, turning the space into a gentle 'guessing game' where guests discover which elements are historic and which are newly crafted.” This interplay brings a fresh dynamism to the heritage structure.

On the third floor, the ancestral room retains a deeply nostalgic atmosphere. The team imagined how Chef Pam’s ancestors—cultured individuals who studied pharmacy and art abroad 80 years ago—might have styled the space upon their return. They preserved the original plaster ceiling and decorative moldings while shifting the palette to deep burgundy, brown, and gold. Timber wall paneling was introduced for thermal insulation, alongside a Chinoiserie mural depicting nine tigers, representing the original founding family members.

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On the balcony, the original glasshouse area was updated with celadon-green louvred shutters to manage acoustic echo and heat gain.

Meanwhile, the fourth-floor Opium Room offers an intimate, moody retreat. Drawing inspiration from the quiet of the night and golden stars scattered as if from Pandora’s box, the space pairs deep navy-blue window frames with dark green walls, accented by gilded lacquerwork that lends a sophisticated, captivating allure.

Adapting a century-old commercial building into a comfortable, light-filled environment required clever spatial solutions. With its narrow five-metre frontage extending deep into the plot, natural light and airflow were inherently limited. The design team resolved this by carefully introducing new window openings and light wells through internal walls nearly 50 centimetres thick—originally built to double as bomb shelters during wartime. At the same time, they retained the central ventilation shaft, allowing natural breezes to flow through as intended.

A favorite feature among guests is the glass elevator that glides slowly between floors. Its measured speed is a deliberate safety feature tailored to the tight lift shaft, fitted with surround sensors to ensure complete safety within the compact historic structure.

Solar heat gain was another major factor, particularly on the rooftop (formerly the Peacock Room), which had been an exposed outdoor terrace. To transform the sun-drenched space into a comfortable lounge, the team built a European-style glasshouse overhead, complete with traditional louvred shutters to filter harsh sunlight—creating one of the restaurant’s most memorable architectural details.

For Sojourn Design Studio, sustainability is rooted in the thoughtful use of resources. The building relies on an efficient VRV climate control system powered by a single outdoor unit tucked away on the roof, serving as the central hub for the entire building. "We wanted to keep the balconies free of air conditioning compressors so they wouldn't radiate heat or clutter the facade," Jern explains. This keeps the exterior clean while keeping energy consumption in check.

Behind the scenes, wastewater management was treated with equal importance. Converting a historic building into a high-end restaurant demands rigorous sanitation standards. Potong installed grease traps and treatment systems to ensure no untreated kitchen runoff enters the public drainage system, taking a responsible approach toward the surrounding neighborhood.

During Phase 2, circular design principles were woven throughout. Privacy screens were built from reclaimed timber, wrapped in Thai silk from the Support Foundation, and detailed with gold leaf applied using modern non-allergenic adhesives. A key highlight was the upcycling of broken porcelain shards into hand-painted floral wall art—an idea inspired by Wat Arun’s mosaics, which repurposed porcelain brought over on trade ships.

Executing the project within tight site constraints proved to be the ultimate test. Phase 2 had to be completed within a strict one-month timeline. Song Wat’s narrow, bustling streets meant large delivery trucks could not park to unload materials. Furthermore, internal pathways had been enclosed with glass during Phase 1, requiring every element to be hand-carried up steep, narrow staircases.

To navigate these challenges, Sojourn relied entirely on off-site prefabrication. "Our drawings were exact, and every piece was pre-cut off-site. There was zero construction waste generated on location," Jern explains. This approach ensured seamless assembly within the short timeframe while achieving a major environmental win: zero site waste.

The transformation of this 120-year-old building stands as a testament to combining artistic vision, structural problem-solving, and a profound respect for heritage. It demonstrates that sustainability begins by preserving what came before—giving historic structures a meaningful new chapter so they can continue telling their story for years to come.

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