The verdant grounds of the Calouste Gulbenkian Foundation in Lisbon are a popular spot for cultural events, weekend sunbathing, and general frolicking. The 18-acre landscape was initially completed in 1969 by landscape architect Gonalo Ribeiro Telles and benefitted from later transformations and rehabilitations, notably a substantial mid-1970s recovery by landscape architect Antnio Viana Barreto. The garden complements the Foundations exquisite late modernist headquarters and museum, designed by Portuguese architects Ruy dAthouguia, Alberto Pessoa, and Pedro Cidtime, that also opened in 1969. But things changed in 1983: The addition of the Centro de Arte Moderna (CAM), designed by British architect Leslie Martin, within the garden became an imposition and a dead-end in the outdoor circulation. Even the Gulbenkians official history states that CAMs construction destroyed the gardens most beautiful views. The garden was itself built on Santa Gertrudes Park, a popular destination that previously supported fairs and a racetrack. Its terrain, including a lake, dates from the 1860s, when a Swiss gardener created a landscape to complement a new neoclassical palace, complete with a medieval-looking stone wall that encircled the grounds. In 1957, the Gulbenkian purchased six-sevenths of Santa Gertrudes Park on which it would realize its campus. (The building and its wall remain in place at the southwest corner of the grounds.) The remaining seventh of the park was acquired by the Gulbenkian in 2005, and the transaction set in motion the ability to extend the garden beyond CAM.Kengo Kuma & Associates and landscape architect Vladimir Djurovic, and others expanded the garden and remodeled CAM. (Fernando Guerra)An international competition to expand the garden and remodel CAM was launched, and a proposal by Kengo Kuma & Associates (KKAA) with Oporto Office for Design and Architecture and Lebanese landscape architect Vladimir Djurovic with Traos na Paisagem Lugar Invisvel was selected from a shortlist of heavy-hitting architects, six Portuguese and six international. The commission was awarded 2019, and new gardens and the renovated building opened to local and international fanfare at the end of September. On a tour just ahead of these festivities CAM director Benjamin Weil demonstrated how transformative this rework will be for the museum.Upon ApproachIn Djurovics new landscape, the biggest change is a new access point: Along the street, the imposing battlements have been removed and replaced by a waist-high wall set back from the street and contoured into a bench. Theres still a gate that can close off the gardens, but now the existing trees shade the praa (plaza), which is usable by alfacinhas (people from Lisbon). The ramparts have come down, revealing a friendlier, more accessible institution. Upon approach, one glimpses KKAAs most striking addition to CAM: a new porch, or engawa, which references the open-air corridors that ring inner rooms in traditional Japanese dwellings. The shade structure runs the length of CAMs footprint, about 300 feet, and in section arcs from a low edge (just above my head) up to the top of the existing facade but is set off, allowing light to wash behind it. On top, the roof is surfaced in 3,274 square white azulejos, while the bottom is finished with overlapping runs of ash.The new porch, or engawa, references the open-air corridors that ring inner rooms in traditional Japanese dwellings. (Fernando Guerra)Propped up on paired tapered steel columns aligned with CAMs existing structural bays, the roof was realized with Buro Happold as a rigid plate with timber box sections infilling between fabricated steel beamsan economic solution with the intention of avoiding deflection over time. The taut sharpness of the canopy as it cantilevers is the key to its weightless appearance.The canopy gets more complex with a second smaller portion at the new museum entrance. Here, the parabola-like roof drapes down and briefly flashes its wooden belly to the park, while the roof tiles peek over the steel edge. Above, the steel is tied to the existing structure, so there are no columns against the building, which further heightens the floating sensation. While the competition-winning imagery, rendered by Luxigon, played up the sense of two shingled surfaces propped up on impossibly thin columns, the feeling survives in the built form, albeit with beefier columns, less like chopsticks and more like clothespins.Interior ArchitectureBeyond a new canopy on CAMs northern entry facing the rest of the grounds, the renovation also fully retooled the museums interior. Perhaps the biggest change is the addition of almost 10,000 square feet of gallery space. Basement rooms were dug out beneath the engawa, adding valuable area that is now accessible via a metal meshlined stair and atrium. Within CAMs Gund Halllike main gallery, the most noticeable change is the inclusion of beefy seismic cross bracing in two locations. (The space now hosts a large, site-specific installation of hanging pieces by Portuguese artist Leonor Antunes in dialogue with selections from CAMs holdings.) In the adjacent low-ceilinged galleries, the ash from Kumas engawa returns as ceiling cladding, along with a new strip of windows that allows viewers to look up and out at the new soffit.Interiors of the museum were also renovated. (Fernando Guerra)CAMs main gallery hosts a large, site-specific installation of hanging pieces by Portuguese artist Leonor Antunes. (Pedro Pina/CGF)One of the new offerings will be an Open Storage program, where more of CAMs 12,000 artworks can be publicly shown. Additionally, the lobby sports the H-Box by Portuguese-French artist and architect Didier Fiza Faustino, a futuristic pod that screens videos by international talent, though the idea is to rotate pieces.KKAAs work continued through the building, with upgraded bathrooms, windows and doors, walkways, seating, and theater. Though spare, there are nice moments: Check out the combined concrete spiral staircase and metal-mesh lounger on your next visit. Even the staff offices are improved with walls of white cork and tables designed by KKAA, and youll be able to sit in KKAA-designed furniture in the new restaurant and gift shop. An added bonus is that the signage is designed by Kenya Haras Hara Design Institute. Though only open for about a month, the project is already the subject of a new book published by AMAG.Nearly 10,000 square feet of space in the basement is now gallery space. (Fernando Guerra)The PortugalJapan ConnectionWhile the commission to a Japanese architect may have caused grumbling among local talent, it illuminates a longform set of architectural exchanges between Portugal and Japan: Renowned Portuguese architect lvaro Siza was in part inspired by the buildings he saw in Japanese architecture magazines that circulated in the 1950s despite the censorship of the Salazar regime. And going further back, the Portuguese were the first Europeans to arrive in Japan in the 16th century (a history dramatized in Martin Scorseses 2016 film Silence). Sizas early Casa de Ch da Boa Nova, for example, drew inspiration from both Japanese and Finnish precedents, and there is a slight stylistic throughline from this masterpiecewhose roof is sandwiched in warm wood and red clay tiles and levitates above the rocky coast north of Portoto Kumas hovering structure. Its fitting that a portion of Sizas archive is held at the Gulbenkian, and a retrospective of his work was on view there over the summer. The resonance is detectable with younger practices: fala atelier got its start during a stay in the now-deconstructed Nakagin Capsule Tower. The cultural exchange continues in the opening festivities: One of the inaugural displays showcases the relationship between artist Fernando Lemos and Japan after he studied calligraphy there (complete with shoji-like exhibition design), and a series focused on contemporary Japanese art offers pieces by artists Go Watanabe, Chikako Yamashiro, and Yasuhiro Morinaga. Additionally, during the vernissage, a crowd of alfacinhas explored the garden and packed under the engawa to hear a moderated conversation between Kuma and Weil.During an opening a moderated conversation between Kengo Kuma and CAM director Benjamin Weil took place. (Joanna Correia)Back to the GardenKKAAs effort improves CAMs clunky, 1980s home to better accommodate its collection and mediates the buildings presence in the garden. In time, likely the most welcome benefit will be the expanded grounds as the planting grows in. Lisbon is lovely in part because of the constellation of leafy praas that dot its hills. The Gulbenkian is one of these, and this expansion is the latest flower in the blossoming relationship between the foundations landscape and its architecture.