Project: Porthmadog House / Location: Porthmadog, Wales (United Kingdom) / Architect and Interior Designer: Ström Architects / Location: Lymington, United Kingdom / Photo credit: James Silverman
Porthmadog House by Ström Architects is a contemporary project set on a sloping coastal site in North Wales. Designed as a forever home for a recently retired couple, the house features two slate-clad ground-floor volumes, a corten-clad upper floor and terraces that seamlessly connect indoor and outdoor living.
Bringing the owners back to their roots, the 5,100-square-foot two-story home overlooking a serene estuary of the Irish Sea is now fully entwined with its setting, echoing the character of the surrounding coastal landscape, the firm says.
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The house was in planning for a long time, with the couple spending five years carefully curating inspiration before approaching Ström at the end of 2019. “The decision to buy the site was deeply personal, not only a strong connection to the location, but the existing property had once belonged to a childhood friend,” the firm says. “Left derelict for 15 years, the house offered both sentimental value and the opportunity for a new beginning.”
The brief called for a home that could bring new life to this cherished site and be robust enough to withstand the harsh coastal weather. It also needed to be warm, comfortable and deeply connected to its setting. “Maximizing the expansive sea and estuary views was a priority, whilst also creating a sense of permanence and protection,” the firm says. “Trusting Magnus Ström completely, the clients provided only a few specific requests: a snug, a gym and social spaces designed to capture the extraordinary outlook.”
Set between sea and estuary, the home responds directly to its site and to the Irish Sea views. Ström Architects mapped wind, rain and sightlines to determine the building’s form, ensuring the design could withstand the elements while maximizing comfort and resilience year-round.
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The lower ground floor, constructed from Welsh slate, anchors the building and offers resilience against the elements while creating visual continuity inside and out. Above, a corten-clad first floor pivots towards the Irish Sea. The angled volume is framed with steel fins for weather protection, solar shading and privacy, but they do not compromise the expansive views. Below, sheltered terraces form outdoor rooms that remain connected to the coastal setting.
This composition of weight and lightness anchors the house to its coastal setting while elevating its connection to the expansive landscape. The design was developed in collaboration with structural engineers Jensen Hunt Design, ensuring both resilience and elegance in the exposed coastal environment.
“For us, creating a distinct identity for each project is essential,” says Magnus Ström, founder of the firm. “Rather than relying on generic floor plans, every home has its own clear form and architectural language, which I believe is very important for all our projects.”
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Ström says the design maximises both sea and estuary views while providing shelter from the coastal winds. The ground floor volumes are carefully positioned, acting as natural windbreaks, shaping a sheltered entrance court and positioning main living spaces where they enjoy uninterrupted vistas. A Japanese-inspired courtyard channels natural light deep into the heart of the home, creating a serene and tranquil setting for the gym. At the same time, the street-facing elevation remains private and enclosed, and the estuary side opens up dramatically to the light and landscape.
Inside, two slate-clad ground floor volumes hold enclosed functions like the snug, gym and plant room, while the main living areas open between them with floor-to-ceiling glazing. Above, the lighter first-floor corten steel structure spans across, creating sheltered terraces below. The home features an open-plan kitchen, dining and living area, a cinema room, a principal suite, a secondary living/work space and three additional bedrooms for the couple’s children.
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Materiality was central to the design, creating a deliberate duality that reflects both local industry and geology. Welsh slate and corten steel reference the region’s slate-mining heritage and ironworking traditions, but reinterpreted in a contemporary way. Locally quarried slate connects the home to the geology beneath it, while weathering materials such as corten and cedar were chosen for their ability to evolve over time. The firm says the slate’s iron content produces warm orange hues as it oxidises, complementing the rich, rusty tones of the corten above. On the other hand, gray-treated cedar silvers gracefully in the coastal air, completing a palette that feels both raw and refined.
“We wanted to create a home that’s beautiful on day one but becomes even more compelling over time,” Ström explains. “The material palette was chosen specifically to achieve that evolution. Welsh slate, corten steel and cedar were not only selected for their durability but for how they age gracefully, settling deeper into the landscape. This combination is unique to the project and deeply rooted in the history and context of Porthmadog. Unlike other houses in the area–often white and interchangeable–this home feels truly of its place, designed for its location and nowhere else.”
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Continuity between inside and out was central to the design. Slate flows from exterior walls into the interiors, while polished concrete flooring grounds the space with a robust, timeless quality. Engineered timber by Havwoods softens the spaces, introducing warmth, complemented by expansive glazing that dissolves the boundary between house and horizon but ensuring energy efficiency and comfort in a harsh coastal environment. Bespoke oak joinery brings tactile refinement to the kitchen, snug and bedrooms, while a restrained natural palette lets the dramatic views take center stage.
From Ström Architects’ perspective, the concept of “new luxury” is defined by a calm, enduring quality rather than ostentation. Space, light and silence take precedence, followed by tactility and craftsmanship, the firm says. Heavy slate walls provide privacy and shelter, allowing the social spaces to open generously to the bay through expansive glazing. Cosy, inward-looking rooms such as the snug and gym are housed within the protected ground-floor volumes, while shared areas embrace long, uninterrupted views.
“Detailing is deliberately restrained, with bespoke joinery designed to keep surfaces clear and daily life effortless,” the firm says. “Here, luxury is not about opulence or excess, but about connection–to nature, history and the rhythms of life. This home reflects a shift in values: away from objects, toward experiences, and toward spaces that feel rooted, timeless and deeply personal.”
