Spanish architect Emma Martí has converted an 18th-century townhouse on the Balearic island of Menorca into the intimate eight-bedroom Hevresac Hotel, taking over all of its five floors from basement to attic.

The building, which originally belonged to a local merchant and privateer, is set in the historic centre of Mahón – a former trade hub that still bears traces of French and English culture after spending many years under colonial rule.

Hevresac owners Ignasi Truyol and Stephanie Mahé brought Martí on board for the renovation in part because she was an old friend, who they thought could be trusted to conserve and enhance the spirit and character of the building.

Martí's aim for the project was to fill the building with light and life while preserving its wealth of existing architectural elements, from wooden beams and mosaic flooring to stucco walls and staircases.

"The aim of the project was to create a fresh and inspiring hotel that values the beauty of the existing architecture," said the hotel's owners.

Hevresac's original floors, covered variously in wooden parquet and encaustic cement tiles, were carefully preserved.

In areas where it was not possible to retain the original elements, Martí chose a new design language using modern equivalents of these original materials, including micro-cement.

The renovation process revealed both the stucco on the walls and the original paintwork on the beams, uncovering part of the building's hidden history.

The original wrought iron columns in the living room are now a celebrated feature. Less noticeable but equally interesting is the Masonic symbolism on the wrought-iron railing of the marble staircase at the entrance.

Martí also wanted to preserve the original room structure of the townhouse.

To allow for this, she added private bathrooms within each of the existing bedrooms using a lightweight timber framing system made of solid Flanders pine, while three-ply spruce boards form partitions, headboards and wardrobes in each bedroom.

"Martí's intention is for the new materials to coexist and harmonise with the originals, providing a new language, lightness and contemporaneity," the owners said.

A new staircase – also utilising spruce ply – now coexists with the original staircase, providing an alternative route through the Hevresac Hotel.

The material is key to the contemporary language of the new insertions, which sit clearly differentiated alongside layers of the building's past.

"I like to work with an honest and frank attitude towards the island's architectural heritage," Martí told Dezeen. "I wanted it to be clear what our intervention was, not to highlight it but to highlight the value of what existed in the building."

To fill the spaces with natural light, several skylights were added on the upper floor, with one above the main stairwell as well as three new openings in the facade.

In the basement, the vaulted ceiling made of local marés stone required an intervention to lighten the space.

Martí's response was to remove a bay of the existing vault and install a new, more comfortable staircase to link the ground floor with the basement and flood the space with light.

Hevresac's choice of furnishings reflects Mahón's cosmopolitan history, including an eclectic assembly of antique, vintage and contemporary pieces from all over Europe.

Among them are Nanimarquina rugs, Achille Castiglioni lights and some of Marcel Breuer's Cesca chairs, as well as items from Menorcan antique dealers including Alcolea & Kraus and Antics Antigüedades.

"It's a kind of synergy," the owners said. "Together, the components project a warm, creative and personal composition, which is more than the algebraical sum of those individual pieces."

Martí, who founded her self-titled studio Emma Martí Arquitectura in Menorca in 2013, has since completed a number of projects on the island.

Among them is a work retreat inside an abandoned girls' school, with design-driven spaces where businesses can host meetings or team-building sessions.

The photography is by Pol Viladoms