Greenhouse Exhibition Hall, Hengshui Botanical Garden (衡水植物园温室展览馆)

Hengshui Botanical Garden, in Hebei, was planned in the south of the city on a natural wetland next to Hengshui Lake. The local authorities wanted a country park and cultural platform open to residents, with ecotourism and plant education. The practice Interval Architects (空格建筑) designed a series of buildings there: the greenhouse hall, an aquatic plant museum, the Botanic Art Center, nicknamed the “tower of bricks”, and a botanic research centre.

The greenhouse hall is dated 2016 to 2021 in the credits published by gooood. The architects' texts contradict each other on completion: the Chinese text places that of the building series in 2019, the English text says 2019 to 2021, and the project sheet gives 2021. The designers set aside the giant sphere often seen in display glasshouses, judged ill-suited to the wetland, in favour of repeated steel modules made with the same moulds to cut cost and construction time. They cite the Crystal Palace of the 1851 World's Fair as their historical reference.

The garden reopened on 1 May 2026 after a refit, with free admission on that occasion according to local press, and new spaces: a children's park, a bird-observation station and a rest area for older visitors. A provincial press article of 6 September 2026 lists the greenhouse hall among the facilities that are “fully open”.

The hall rests on the repetition of inverted pyramidal steel units whose assembly forms a folded roof; the main structure is 18 m high. Thirteen trapezoidal concrete bases, standing on a red brick plinth, carry the units, which are wrapped in a glass curtain wall. The components are prefabricated with the same moulds and parameters, and a mixed structural system leaves the interior free of columns.

Hebei's heavy snowfall explains the steep roof slopes: downpipes at the junctions of the pyramids collect meltwater into a cistern. Roller shading blinds are hidden behind the curtain wall, auxiliary lighting is built into it, and the climate-control systems are concealed in the beams and trusses. Small timber volumes, the “space-boxes” (shops, offices, washrooms, storage), slip beneath the envelope; their height is 4 to 6 m in the Chinese text and 3 to 4 m in the English text. The main entrance, to the north-east, is an unglazed pyramidal steel unit that creates a shaded space; three secondary entrances open to the west, towards the lake, and to the south, towards the loop road. The floor area is 3,113 m² gross in the project sheet, about 3,000 m² in the architects' introduction and 3,570 m² in local press.

The architects planned two zones. The tropical zone puts tall trees at the centre of each pyramidal unit and low seasonal flowers on the four sides. The sand-and-desert plant zone occupies a separate, lower unit in the south, to meet these plants' particular needs for area, temperature, humidity and soil.

Local press on 1 May 2026 describes a constant-temperature greenhouse plant hall (恒温温室植物馆) of 3,570 m² gathering more than 200 tropical, subtropical and desert species, and names bougainvillea trunks (三角梅桩), 鸭脚木 and date palms (海枣). Another article, of 6 September 2026, credits the garden as a whole with more than a thousand species and 22 themed gardens; it does not detail the contents of the hall.

The hall occupies the southern part of the garden, at the edge of the central lake, facing the Botanic Art Center and its brick tower across the water. The main entrance is to the north-east; two secondary entrances lead down to the lake on the west, and a third joins the loop road to the south.

The visit can continue to Hongfu Terrace (鸿鹄台), the garden's highest point with a view over the whole park, and to the panoramic platform of a 36 m chimney, which the press of 6 September 2026 lists among the facilities that are open. The architects mention, for the lake, a migratory bird passage from mid-October to early November, and the garden opened a bird-observation station in 2026.