Kimbell Art Museum Case Study: Plan, Section and Cycloid Vaults (Louis Kahn)

The Kimbell Art Museum in Fort Worth, Texas, is an art museum designed by Louis I. Kahn for the Kimbell Art Foundation, commissioned in 1966 and opened in October 1972. Its plan is sixteen parallel concrete shells, each about 30.5 m (100 ft) long, and its idea is daylight: a slot at the crown of each shell lets the sky in, and a hanging aluminium reflector throws that light onto the curved concrete ceiling. Below: brief, site, plan, section and structure, materials, light, reception, the 2013 Piano Pavilion and lessons for India.

Kimbell Art Museum: the facts

Architect: Louis I. Kahn, with Marshall Meyers as project architect. Associate architect: Preston M. Geren & Associates. Structural consultant: August E. Komendant. Lighting consultant: Richard Kelly. Concrete consultant: Fred Langford. Landscape: Texas Architect lists George Patton; the University of Pennsylvania archive credits Harriet Pattison. Contractor: Thos. S. Byrne.

Client: Kimbell Art Foundation, with founding director Richard Fargo Brown.

Location: Cultural District, Fort Worth, Texas, USA, on a 3.8 ha (9.5 acre) site given by the city.

Designed and built: Kahn hired on 5 October 1966; ground broken in June 1969; opened on 4 October 1972.

Type and size: art museum, about 11,150 m² (120,000 sq ft). Cost: $6.5 million, or $54 per sq ft in 1972.

Status: open to the public. AIA Honor Award 1975; AIA Twenty-five Year Award (1997 per Texas Architect, 1998 per the Penn archive). Altered: roof recovered twice; Renzo Piano Pavilion added to the west in 2013.

For how to lay out your own sheets, see our guide on how to document a building.

The brief: a foundation, a director and a policy on light

Kay Kimbell, a Fort Worth businessman, set up the Kimbell Art Foundation with his wife Velma in 1935 and, when he died in 1964, left his estate to it to build "a public art museum of the first rank" (Handbook of Texas, Edmund P. Pillsbury). Founding director Richard Fargo Brown wrote the brief. Igor Fracalossi's ArchDaily AD Classics article (2011) says Brown's Policy Statement made natural light a vital part of the design, and that the other architects considered included Marcel Breuer, Mies van der Rohe, Pier Luigi Nervi, Gordon Bunshaft and Edward Larrabee Barnes.

Gifford Pierce's paper "Natural Lighting at the Kimbell Museum" (ACSA, 1998) quotes Brown's pre-architectural programme. Without daylight, he wrote, visitors would feel "vacuum packed in a can". He wanted weather and seasons to be felt inside, yet the same programme said artificial light must be able to do the whole job. That balance is the key to the building. Kahn was hired on 5 October 1966, aged 65 (W. Mark Gunderson, "Rare Forms of Light: The Kimbell Art Museum at 50", Texas Architect, 2022).

Site and context: a park, a row of elms and a west front

The city gave a 9.5 acre (3.8 ha) site in Amon Carter Square Park (Handbook of Texas). Allées of cedar elms were about 30 years old when Kahn started; the design kept them, and Kahn worked out the approach with Harriet Pattison as an "entrance of the trees" (Texas Architect).

The front faces west, to the park. Pierce explains why the vaults run north to south: the slots then gather sun through most of its daily arc, with less difference between summer and winter. The west porches shade the galleries from the setting sun.

Kimbell Art Museum architecture analysis: the concept

Kahn's own words, as Pierce quotes them, set the theme. In "Silence and Light" (published 1970) he asked how anyone could imagine "a building of spaces not seen in natural light". In a 1967 lecture he predicted that rooms structured in concrete would have "the luminosity of silver".

The idea is a single repeated room: a long vault with a slot of sky at its crown. Pierce, drawing on Marshall Meyers's "Masters of Light: Louis Kahn" (AIA Journal, 1979), traces how the section developed:

Meyers's early drawings show a ceiling of two quarter circles joined by a flat strip with the skylight in the middle.
A later version used the cycloid curve, which, by Pierce's account, Meyers suggested to Kahn.
The reflector began as a transparent, lightly mirrored surface.

The roof is the room, and the plan is that room repeated.

Kimbell Art Museum floor plan: sixteen vaults in three units

The builder, Thos. S. Byrne, describes the plan as a modular arrangement of 16 cycloid vaults. Each vault unit is about 30.5 m by 6.1 m (100 by 20 ft) and stands on four columns 0.6 m (2 ft) square at its ends. Between the vaults run flat reinforced concrete channels about 2.1 m (7 ft) wide that carry air conditioning and electrical services.

How the vaults are grouped:

Three units. Six vaults in the north wing, four in the centre, six in the south wing, separated by glazed joints (Pierce).
A U around an entrance court. Two wings reach west around an entry court of gravel and small trees, and the west vault of each wing is an open porch beside a pool (Historic Fort Worth). Fracalossi describes the west front as three 100 ft bays: two porticoes either side of a recessed, glazed entrance.
Three courtyards. They bring light, air and views into the middle of the plan (ArchDaily). As Pierce saw them in 1996, there was a larger north court, its light softened by rose vines on steel cables, and a smaller south court covered by a white net.
Two levels. Most galleries are on the upper level (ArchDaily); offices are built below grade and open to the parking at the back (Historic Fort Worth).

Schematic plan of the Kimbell Art Museum, north at the top: three units of parallel vaults running north to south, six vaults in the north wing, four in the centre and six in the south wing, with flat service channels between the vaults and a column at each corner of every vault; the westernmost vault of each wing is an open portico with a pool in front; the centre is set back behind an entrance court planted with a grid of trees and closed by a glazed entrance; a larger north court and a smaller south court are cut into the wings; the Renzo Piano Pavilion sits about 65 yards to the west and visitors from the car park arrive on the east side — Sixteen vaults in three units: the plan is one repeated bay, with courts and porticoes cut out of it rather than rooms added to it. Diagram: MOA

One weakness: Kahn meant visitors to arrive from the park on the west, but most came in through the east door from the car park, which he considered the back entrance (ArchDaily). For Kahn's own drawings, see the Kimbell collection at the University of Pennsylvania's Architectural Archives: 34 originals and 6 rendered prints.

Kimbell Art Museum section and structural system

The roofs are usually called vaults, but they do not work like masonry vaults. Anthony Denzer's paper "Picture-Building: Le Corbusier, Louis Kahn and the Problem of Representation" (ACSA, 2002) explains that they are shells, which behave differently from compression vaults: the curved end of each shell carries large tensile loads. The builder and Historic Fort Worth describe them as post-tensioned concrete spanning 100 ft (30.5 m) and supported only at their corners.

August Komendant was the structural consultant (Texas Architect), credited as its structural engineer for 1966 to 1972 by Estonian World (2022). Gunderson writes that at one point Komendant was put in control of the project, as the one party the others trusted.
Komendant shaped the end walls too. Kahn wanted a continuous 5 cm (2 in) glass strip between each shell and its non-structural end wall. Denzer, quoting Komendant's memoir, says the engineer insisted on about 23 cm (9 in) at the columns and 10 cm (4 in) at the crown, so the wall could not be read as holding up the shell.
The design has been checked since. Mikhail Osanov's Bucknell honours thesis (2014) modelled the shells by finite element analysis and found results close to Komendant's hand calculations, with prestressing the main source of their efficiency.

Schematic cross-section of one Kimbell gallery vault: a thin cycloid concrete shell rising from edge beams, split at the crown by a narrow skylight slot bridged by struts; under the slot hangs a winged aluminium reflector with a solid centre strip and a small fin; arrows show daylight entering the slot, bouncing up off the reflector onto the curved ceiling and spreading down to the travertine walls, with a little light passing through the perforations to the floor; flat service channels with ducts sit either side of the vault, and a lower level of offices and services lies beneath the gallery floor — Direct sun is kept off the walls: the reflector throws daylight onto the concrete ceiling, which becomes the light source for the room. Diagram: MOA

Sources do not agree on the width of a vault. The builder gives 20 ft (6.1 m); Pierce describes a 23 ft (7 m) cycloid span plus 7 ft of flat ceiling, with one 2 ft 6 in (0.76 m) skylight per bay. No source we opened explains the difference.

Kimbell Art Museum materials

The builder lists the materials: reinforced concrete, Italian travertine from Bagna di Tivoli, lead-coated copper roofing, glass and steel outside; concrete, travertine, quarter-sawn white oak, anodised aluminium, stainless steel, slate and tile inside.

Concrete as cast. As Kahn directed, the shells were left untouched after the forms came off, so they show the grain and nail lines of the marine plywood, plus patches and puddle marks. From the floor these read as soft variations in the light (Pierce).
Travertine as infill. The end walls under each shell are travertine-faced and carry no load. Denzer quotes Kahn calling it "an unwanted wall anyway".
The roof. Gunderson counts three roofs: two of lead with calcium, and the current one of lead-coated copper.

The south wing of the Kimbell Art Museum seen from the lawn under a blue sky: an open concrete portico with a curved lead roof at the west end, a shallow pool in front of it, and a row of six cycloid vault ends along the side, each a travertine wall under a concrete arch with a thin glass strip between them — The south wing in 2011: the open portico on the west, and the six vault ends that repeat along the side elevation. Photo: Carol M. Highsmith, Public domain, via Wikimedia Commons

Kimbell Art Museum lighting: the natural light fixture

Pierce and the Richard Kelly Grant tell how the reflector was resolved:

Glass first. Bent glass with a thin aluminium coating looked good in Plexiglas models, but cost, durability and code rules for overhead glass ruled it out (Pierce).
Kelly's material. Richard Kelly moved from acrylic to perforated aluminium: reflective, partly transparent, cheaper and easier to maintain (Richard Kelly Grant).
The curve. In February 1969 Kelly drew the reflector curve freehand. About a year later Isaac Goodbar, an associate of Edison Price, calculated its coordinates by computer (Richard Kelly Grant).
Failed prototypes. In June 1971 two full-size prototypes went up. One let noon sun onto the south-facing walls; the other was too dark. Frank Sherwood of the Fort Worth associate office proposed a solid top strip with perforations either side. Tests ran for eight months; a 15 cm (6 in) fin was added after opening (Pierce).
Where art is not hung, as in the lobby and library, the reflectors are fully perforated (Richard Kelly Grant).

Pierce measured the light on 22 March 1996, a sunny day. At midday the sky above the skylight read about 9,700 lux (899 foot-candles), the ceiling about 230 lux (21.5 fc) and a gallery wall about 57 lux (5.34 fc). At midday 54% of the wall light came from the ceiling and the rest from incandescent lamps: sky brightness cut by a factor of over a hundred.

The limits: a museum guard told Pierce that a passing cloud dims the galleries suddenly enough to unsettle visitors, and on dull days the ceilings turn grey. Kelly's linear electric light under each reflector was cut for budget, and track lights went in (Richard Kelly Grant). Daylight is the ambient light; lamps light the paintings.

Interior of the Kimbell Art Museum looking along a vaulted hall: a long concrete cycloid ceiling with a row of curved aluminium reflectors hanging below the skylight slot at its crown, travertine walls, square concrete columns in the foreground, an oak floor, and a glazed wall on the right — Inside in 2021: the reflector runs the length of the vault and the concrete ceiling glows with the light it throws upward. Photo: Joe Mabel, CC BY-SA 4.0, via Wikimedia Commons

Climate and services

Air and power run in the flat channels between the shells, so the curved ceilings carry no ducts (Thos. S. Byrne). More light comes from the courts, the lunette glazing at the vault ends and the glazed joints between the units (Pierce). Kelly advised on ultraviolet filtering for the skylights and on vines in the courts to soften the light (Richard Kelly Grant).

Reception: praise, delays and a fight over an extension

Awards. AIA Honor Award in 1975 (Historic Fort Worth). AIA Twenty-five Year Award: Gunderson says it won at local, state and national levels in 1997, its first year of eligibility; the Penn archive gives 1998.
Critics. Gunderson quotes Ada Louise Huxtable after her first visit: the museum was "even more beautiful than I expected".
Delays. Kahn's contract assumed three years; ground was broken without complete construction documents, and relations on site were strained (Texas Architect).
The 1989 extension. In 1988 director Edmund Pillsbury proposed extending the vaults north and south; after protests it was dropped in 1989. Esther Kahn wrote in the New York Times that her husband "felt he had created something that was perfect in itself" (quoted in Texas Architect).

The Renzo Piano Pavilion (2013)

The extension was built as a separate building. Renzo Piano Building Workshop designed it from 2007 to 2013, with Kendall/Heaton Associates of Houston, about 65 yards (59 m) west of the Kahn building, facing its west front:

It roughly doubles the gallery space and adds education studios, a 298-seat auditorium, a library and an underground car park, with about half its footprint below ground (RPBW).
Its roof combines glass, wooden beams, aluminium louvres, photovoltaic cells and fabric (RPBW).
David Dillon's Architectural Record report (May 2010) gave 85,000 sq ft (about 7,900 m²) and a $70 million budget at design stage, and quoted Piano: "at the right distance for a conversation".
Its garage brings visitors up on the west, so they reach Kahn's front door as he intended (RPBW).

What designers in India can take from it

These are our reading, not claims made by the sources.

Bounce daylight, do not admit it. Indian skies are bright for most of the year. A narrow slot and one reflective surface turned a very bright sky into soft room light here. For museums, libraries and studios, try north-south roof slots over a reflector or white soffit, and test the section in a model under real sun.
Give services their own strip. In Indian institutional buildings, where air conditioning often comes later, a planned service zone between structural bays saves the ceilings from being cut up.
Bring the engineer in at concept. The section is as much Komendant's as Kahn's, down to the width of the glass at the ends. A thin shell left as the finish needs careful formwork, supervision and a structural engineer from day one.
Budget for mock-ups. Two full-size reflector prototypes failed. A full-size mock-up of a jaali, louvre or skylight costs little next to a building that does not work.

For Kahn in South Asia, see our IIM Ahmedabad and National Assembly of Bangladesh case studies. If you are choosing a museum or gallery thesis, our list of B.Arch thesis topics by typology is a place to start.

Visiting the Kimbell and seeing the drawings

The Kahn building now holds the permanent collection, and temporary exhibitions are in the Piano Pavilion (Architectural Record, RPBW). For hours, admission and directions, check the museum's website, kimbellart.org. Approach from the west, through the trees and under a portico, to enter the building as it was designed.

See how Indian studios handle light, concrete and courtyards: browse projects by MOA members.

FAQ

When was the Kimbell Art Museum built?

Louis Kahn was hired on 5 October 1966, construction began in June 1969, and the museum opened on 4 October 1972. The Renzo Piano Pavilion next door opened in 2013.

Who was the architect of the Kimbell Art Museum?

Louis I. Kahn, with Preston M. Geren & Associates as associate architect, August Komendant as structural consultant and Richard Kelly as lighting consultant. Historic Fort Worth calls it his last project before his death in 1974.

What materials were used in the Kimbell Art Museum?

Concrete, post-tensioned in the shells; Italian travertine for the infill walls and floors, quarter-sawn white oak for floors and doors, anodised aluminium for the reflectors, stainless steel, glass, and a lead roof that has been replaced by lead-coated copper.

How many vaults does the Kimbell Art Museum have, and how big are they?

Sixteen, in three units of six, four and six. Each is about 30.5 m (100 ft) long and is given as 6.1 m (20 ft) wide by the builder, with 2.1 m (7 ft) service channels between them.

How is the Kimbell Art Museum lit?

Daylight enters through a 0.76 m (2 ft 6 in) slot at the crown of each vault, hits a perforated aluminium reflector and bounces onto the concrete ceiling, which lights the room. Track lights light the paintings themselves.

Sources

Texas State Historical Association, Edmund P. Pillsbury: Kimbell Art Museum, Handbook of Texas, 1976, revised 18 June 2020: founders, bequest, site, cost, area, opening (accessed 3 Nov 2026)
Texas Architect, W. Mark Gunderson: Rare Forms of Light: The Kimbell Art Museum at 50, Sep/Oct 2022: team, commission and opening dates, cost per sq ft, roofs, 1988 to 1989 extension, awards, quotes (accessed 3 Nov 2026)
ACSA, Gifford Pierce: Natural Lighting at the Kimbell Museum, 86th ACSA Annual Meeting and Technology Conference, 1998, pages 89 to 93: Brown's programme, orientation, reflector history, light measurements, courts (accessed 3 Nov 2026)
ACSA, Anthony Denzer: Picture-Building: Le Corbusier, Louis Kahn and the Problem of Representation, 90th ACSA Annual Meeting, 2002, pages 523 to 526: shell behaviour, Komendant and the glass strips (accessed 3 Nov 2026)
Richard Kelly Grant: The Kimbell Art Museum: Kelly's role, reflector material and curve, artificial lighting (accessed 3 Nov 2026)
Thos. S. Byrne: Kimbell Art Museum: vault and column dimensions, service channels, materials, area (accessed 3 Nov 2026)
Historic Fort Worth: Kimbell Art Museum: U-plan, porticoes, below-grade offices, 1975 AIA Honor Award (accessed 3 Nov 2026)
ArchDaily, Igor Fracalossi: AD Classics: Kimbell Art Museum / Louis Kahn, 31 March 2011: Brown's policy, shortlist, west front, courtyards, back entrance (accessed 3 Nov 2026)
Architectural Archives, University of Pennsylvania: Kahn: Kimbell Art Museum: drawings held, credits, 1998 award (accessed 3 Nov 2026)
Bucknell University, Mikhail Osanov: Evaluation of the Design of Komendant's Cycloidal, Thin Shell Roofs at the Kimbell Art Museum Using Finite Element Analysis, honours thesis, 2014, abstract (accessed 3 Nov 2026)
Estonian World, Silver Tambur: A book about Estonian engineer August Komendant published by Birkhäuser Verlag, 1 November 2022 (accessed 3 Nov 2026)
Renzo Piano Building Workshop: Kimbell Art Museum Expansion: dates, team, programme, roof, siting (accessed 3 Nov 2026)
Architectural Record, David Dillon: Piano Conceives a Respectful Addition to Kahn's Kimbell Masterpiece, 28 May 2010 (accessed 3 Nov 2026)
Kimbell Art Museum: kimbellart.org, linked for visiting information only (accessed 3 Nov 2026)