Okayama Prefectural Office West Building

Maekawa Returns to His Own Site, Fourteen Years On

The Okayama Prefectural Office West Building (岡山県庁西庁舎, Okayama-kenchō Nishi-chōsha) is a five-storey reinforced concrete office block in Uchisange, Kita Ward, Okayama City, completed in February 1971 to a design by Kunio Maekawa, and entered on Japan's register of Tangible Cultural Properties on 3 December 2024.

It stands west of the main office block and the assembly wing, both of which the same architect had finished in 1957. Fourteen years separate the two campaigns, and the West Building is where you can see what changed in Maekawa's thinking during them.

The Agency for Cultural Affairs records it as reinforced concrete, five storeys above ground and one below, with a building area of 702 square metres and a rooftop tower. Its registration number is 33-0372. Of the three registered buildings on the site, it is the smallest in footprint and the last to be built.

Concrete Instead of Glass

The main building of 1957 wraps its upper storeys in black-framed curtain walling, glass and steel hung in front of the structure. The West Building does something close to the opposite. Its walls are struck concrete, left as they came out of the formwork, and the structure is the appearance.

From the third floor up the outer wall projects beyond the storeys below. Deep balconies run behind that projection, and the depth is the point: shadow gathers in them, so the elevation reads as carved rather than applied.

Look at the west front and a grid emerges. Vertical mullions and horizontal handrails, both in concrete, divide the facade into a lattice. The prefecture's registration assessment describes the resulting elevation as light in feel, which sounds contradictory for a building this heavy until you stand in front of it and see how much of the wall is actually void.

Ribbon windows appear here as well, one of Le Corbusier's five points for modern architecture and a thread running through the whole complex. The contrast between this concrete grid and the black glass next door is the most instructive fifty metres of walking anywhere on the site.

The Ground Floor Gives Itself Away

At street level, most of the West Building is not enclosed at all. Apart from the entrance hall, the entire ground storey is piloti, an open colonnade under the mass above. A stair opening at the centre leads down to the underground passage linking the buildings on the site.

Maekawa had used piloti at the main building in 1957, lifting two storeys of floor to make a covered void people could walk through. Here he applied the same device at smaller scale and to a more practical end, since the West Building sits in the interior of a working government compound where movement between blocks matters more than a ceremonial approach.

The effect is that the building appears to rest on air. Its bulk begins at first floor level, and beneath it the ground continues uninterrupted toward the courtyard and the main block.

A Quiet Piece of Engineering History

In July 2004 the prefecture completed seismic strengthening of the West Building using base isolation. The building was separated from its foundation by bearings that absorb ground movement instead of transmitting it into the frame.

This deserves attention. Base isolation retrofits on existing mid-rise office buildings were still uncommon in Japan at that date, and the method was chosen partly because it strengthens a structure without adding braces and thickened walls to the elevations. The concrete lattice Maekawa designed survived the work intact. Further refurbishment followed in 2024.

The complex as a whole was selected by DOCOMOMO Japan in 2016 as a significant work of the modern movement, on criteria including composition by line and plane rather than ornament, and technical achievement expressed as design. The West Building satisfies both readings, in 1971 through its formwork and in 2004 through what was placed beneath it.

The prefecture's assessment for registration argues that the three buildings together represent the architectural expression of post-war democracy and the realisation of modernism at the scale of a large government complex. The West Building is the part of that argument concerned with continuity: a later addition that harmonises with what came before without imitating it.

Visiting

The prefectural office grounds are open and ungated, so the West Building can be viewed at any hour. The west front, where the concrete lattice is fully legible, faces away from the main approach, which means most visitors miss it. Walk around to that side. Standing under the ground floor piloti and looking up at the underside of the projecting wall is the other view worth taking.

Interior access is limited, since the building houses working offices. Photography from the grounds and surrounding streets is unproblematic; ask at reception about interiors.

The prefecture runs a free guided tour of the office complex, roughly ninety minutes for about ten people, opening with a short presentation on Maekawa before the walk. Applications go through the Okayama Prefecture electronic application service, open on the first day of each month and close seven days before the date. Groups of ten or more contact the building control division on 086-226-7504. Note that the published route centres on the main building, so confirm what is covered.

Offices close on weekends and public holidays. Buses bound for Asahigawasō from JR Okayama Station reach Kenchō-mae in about ten minutes; the station is around twenty-five minutes on foot. Visitor parking costs 100 yen per hour. The main building's ground floor, a short walk away, has a public canteen and a gallery corner on Maekawa's work, both free to enter on weekdays.

Two more Maekawa buildings stand within walking distance, the Hayashibara Museum of Art and the Tenjinyama Cultural Plaza of 1962. Seeing the three in sequence, 1957, 1962 and 1971, shows the shift in his handling of concrete more clearly than any book.