Atlantic Permanent Building, Norfolk: Floodproofing a 1954 Modernist Bank

Sophisticated, modern and convenient: the words used for the rehabilitated Atlantic Permanent Apartments and D'Art Center in Norfolk, Virginia, fit the building just as well when it opened in 1954 as the headquarters of the Atlantic Permanent Bank. Besides preserving the sleek lines of Norfolk's only International Style building, the rehabilitation made it something new: floodproof.

A building in the path of water

The building stands in Norfolk's Art District and the Auto Row Historic District, within walking distance of downtown's restaurants and entertainment — and in the middle of many flood risks. Norfolk's sinking ground, much of it fill, a high water table and stormwater runoff all compound the fact that the building sits next to the lowest point in the area. The city's floodplain rules require elevation and floodproofing for substantial improvements, but raising the building by six feet, above the floodplain and coastal flood hazard levels, made no sense.

Two kinds of floodproofing

The team instead combined dry and wet floodproofing to make the building more resilient while keeping its character-defining features, such as the large historic glass panels at the Boush Street entrance and the strongly horizontal massing.

Wet floodproofing lets water in without lasting harm:

• shatterproof glass;
• moisture-resistant gypsum board with fibreglass on interior walls, to resist mould;
• flood barriers for the entrances — aluminium panels set by hand into steel channels — for low-level nuisance flooding;
• two sump pumps to remove water from inside after a heavy flood.

With these measures, the interior can survive flooding up to six feet above the finished floor.

Dry floodproofing keeps water out where it cannot be allowed in. The elevator shaft and equipment room on the first floor were sealed with waterproof membranes and sealants on reinforced concrete walls and slabs, and electrical circuits and outlets were raised to the base flood elevation, protecting costly equipment that cannot survive floodwater.

A new life

The result is a building that can come through a significant flood and keep serving the community in its new use with its historic identity intact. The former savings bank and office building now holds an artists' collaborative in the double-height lobby, working studios and community classrooms on the lower level, and distinctive apartments above.

Sources

Based on "Case Study: Atlantic Permanent Building, Norfolk, Virginia," published by the National Park Service, Technical Preservation Services; rewritten in hubnx's own words.

• The case study's photograph, credited to Yuzhu Zheng, is not reproduced.