Hall of Nations Case Study: Space Frame, Structure and Demolition (Raj Rewal)

The Hall of Nations was an exhibition hall at Pragati Maidan, New Delhi, designed by Raj Rewal with the structural engineer Mahendra Raj and opened for the Asia 72 trade fair in 1972. Its walls and roof were a single concrete space frame in the shape of a truncated pyramid, spanning 78 m without a column, and it was cast in place largely by hand. It was demolished on the night of 23 to 24 April 2017. Below: brief, structure, construction, the court cases in dated facts and lessons, with MOA diagrams.

Hall of Nations: the facts

Architect: Raj Rewal (Raj Rewal Associates). Structural engineer: Mahendra Raj. Contractor: Puri Construction, the lowest tenderer, according to Mahendra Raj. Rewal also credits an engineer he names as Dorairaj (Durai Raj in another interview).

Client and occasion: built for the Government of India's Asia 72, the international trade fair held in the 25th year of independence. The V&A says Rewal won a competition for the complex; the M+ archive notes say the commission came under Prime Minister Indira Gandhi. The India Trade Promotion Organisation (ITPO) later ran the site.

Location: Pragati Maidan, New Delhi.

Designed and built: work began in 1969 according to The Hindu; Rewal's office and the V&A date the design to 1970. Completed in 1972. Sources give the construction time as 15, 18 or 22 months (see below).

Type and size: exhibition hall, the largest of four truncated pyramids, with the Nehru Pavilion nearby. 82 m x 82 m at the base and 27 m high, with about 6,700 sq m of column-free floor (Mahendra Raj Consultants); 78 m clear span, inside height 3 m to 21 m (Raj Rewal Associates).

Status: demolished in April 2017. The site is now part of the International Exhibition-cum-Convention Centre, named Bharat Mandapam in July 2023.

What was the Hall of Nations? The brief and the client

Asia 72 was part of the celebrations of 25 years of independence. In his 2017 essay, Martino Stierli, MoMA's chief curator of architecture and design, describes it as a building meant to show India as a modern nation built on science and technology. The Twentieth Century Society's building of the month entry (Christopher Turner, July 2024) notes that Indira Gandhi inaugurated it.

Rewal's own project page, on the Raj Rewal Associates site, sets out the brief as a set of limits: little time, scarce materials, and a labour force rather than machines. He calls the answer "intermediate technology", neither traditional craft nor imported industry. It also places the complex at the centre of 130 acres of exhibition grounds that Rewal planned.

The time limit was real. Rewal told Nirmal Kulkarni in October 2017 (reproduced on Architexturez) that the structure had to go up in 18 months, and told architecture.live in June 2017 that the design took two to three months.

Site and context: Pragati Maidan in 1972

The Hall of Nations was not Pragati Maidan's only experiment. Mahendra Raj Consultants list Charles Correa's Hindustan Lever Pavilion (1961) there, and from 1971 and 1972 Kuldip Singh's M Pavilion and a folded-plate steel pavilion for Delhi Cloth Mills by Jasbir Sawhney. Raj engineered all of them.

The Hall of Nations was the largest of four truncated pyramids linked by ramps (MoMA; V&A). To its west, the C20 entry describes the Nehru Pavilion as an underground gallery, the "negative" of the pyramids, with a mound that recalls a stupa.

Climate shaped what follows: Rewal told Kulkarni his starting point was the strength of the Indian sun. For how ordinary houses in the city deal with the same heat, see our guide to building materials in Delhi NCR.

Hall of Nations concept: a three-dimensional jaali

Rewal had studied space frames while in London, according to the M+ archive notes on his drawings. In the Kulkarni interview he names two other sources. One was Pier Luigi Nervi's concrete trusses: if those could be made in concrete, he asked, why not a space frame? The other was the triangular lattice of Indian geometry, which he traces to yantras and to Mughal screens.

The key idea is that one element did two jobs. A span of 256 ft needed a frame about 16 ft deep, Rewal says, and that depth could also act as a sun breaker. His office describes the result as a version of the jali, the perforated screen that cuts glare and lets air through. If you are designing screens at house scale, our jaali design guide covers patterns, materials and where they work.

Hall of Nations plan and dimensions

Rewal's office describes the plan as a vast square with eight openings, closed by pivoted steel gates and reached by stairs and ramps, with services and facilities tucked under those approaches. Mahendra Raj Consultants say the pyramid stood on eight points. Their figures for the main hall:

Base: 82 m x 82 m.
Height: 27 m.
Floor: about 6,700 sq m of uninterrupted exhibition space.
Each Hall of Industries: 44 m x 44 m, 16 m high.

Rewal's office gives a 78 m clear span inside, with inside heights from 3 m at the edges to 21 m: the free space within the frame. MoMA gives 144 ft long and up to 90 ft high; we could not reconcile that length with the other sources.

No source describes the layout of the four halls closely enough to diagram it without tracing a real drawing, so MOA has not drawn a plan. Rewal's floor plan is in the M+ collection in Hong Kong, with two sections, a perspective and two joint sketches.

Hall of Nations section and structure: Raj Rewal and Mahendra Raj

In section the hall was a truncated pyramid whose sloping sides and flat top were one double-layer space frame. Mahendra Raj, in excerpts published by architecture.live in April 2018, describes the scheme as basically "a pyramid with a double layered space-frame". He made every member the same size in geometry, so that pyramidal units could be placed side by side, and he notes that up to nine members met at some joints.

Schematic section of the Hall of Nations: a truncated pyramid whose sloping walls and flat top are one deep double-layer space frame, drawn as a band of zigzag members; sun rays strike the outer layer and an arrow shows air passing through the open frame; inside, a dashed line marks the 78 m clear span and a note gives inside heights from 3 m to 21 m; below, a dimension line gives 82 m by 82 m at the base, black blocks mark support points and dashed piles go into the ground; to the right a smaller truncated pyramid is labelled as a Hall of Industries, 44 m by 44 m and 16 m high — The walls and roof were one deep concrete frame that carried the span and shaded the hall. Figures are as the named sources give them; the drawing shows the principle, not the real geometry. Diagram: MOA

The chapter on the hall in The Structure: Works of Mahendra Raj (Vandini Mehta, Rohit Raj Mehndiratta and Ariel Huber, 2016), whose drawing captions are reproduced on Architexturez, adds the detail:

The module. A drawing of levels 1 and 2, dated 10 November 1971, shows one module emerging from three inverted pyramids, multiplied across inner and outer nodes until the frame closes as a truncated pyramid.
The member. Each member had a rhombic cross-section with chamfered edges, a 25 cm face and an area of 585 sq cm. The rhombus came out of the search for a joint that was easier to build, and suited the slopes of the pyramid better than a square, rectangle or circle.
The joint. The C20 entry describes nine members meeting at a rhombic concrete joint. Rewal's own sketch of the "nine-point joint" is one of the five Hall of Nations drawings at M+.

Below ground, Mahendra Raj Consultants say the Hall of Nations sat on piles tied by post-tensioned plinth beams, stressed in stages, while the Halls of Industries used spread footings tied with high-tensile steel bars.

Was it the first? The V&A says the world's first and largest-span concrete space frame; MoMA, the largest when completed; Mahendra Raj Consultants, the first in India and possibly the world.

Hall of Nations material and construction: concrete, cast by hand

The choice of concrete was economic: Rewal told Kulkarni that steel in that quantity was not available in India, and MoMA gives the same reason.

The method changed after the design was done. Mahendra Raj's account runs in three steps:

Precast first. With steel members unavailable, he designed the frame in precast concrete members.
No precast bidder. No contractor would take on the accuracy precasting demanded, and the job went to the lowest tenderer, Puri Construction.
Cast in situ. The design was reworked for concrete poured with shuttering and bars already in place, and the joints worked out for precast had to change.

Mahendra Raj Consultants' note agrees: a nine-member joint was developed for precast work, but the builder preferred casting in situ.

Four-part schematic of the Hall of Nations space frame: first, a strip of frame with an outer row of nodes and an inner row offset by half a bay, joined by diagonals into inward-pointing units about 16 ft deep; second, a single dark node with nine members radiating from it; third, the cross-section of one member, a rhombus with chamfered corners, labelled face about 25 cm and area 585 sq cm; fourth, three boxes in sequence: precast design, no contractor for precast, cast in situ; a band at the bottom notes some 300 workers living on site, 50 carpenters making timber boxes and concrete poured by hand and carried up bamboo scaffolding in baskets — The frame was designed as repeating precast pyramid units and then cast in place by hand. Principle only: Rewal's own joint and section drawings are in the M+ collection. Diagram: MOA

The site ran on labour. The C20 entry says about 300 families lived on site, fifty carpenters made the wooden boxes the concrete was poured into, and concrete went up a bamboo scaffold in baskets; the V&A says 300 workers poured it by hand.

Sources disagree on time: 15 months to analyse, design and build (Mahendra Raj Consultants), 18 months (Rewal; the V&A says just over a year and a half) and 22 months, within budget (The Quint, 26 April 2017).

Black and white photograph of the Hall of Nations at Pragati Maidan: a large truncated pyramid made of a lattice of concrete triangles, closed with panels in some places and open in others, rising over a paved forecourt, with concrete stairs and ramps climbing to an entrance on the right under a cloudy sky — The Hall of Nations in 2008, nine years before it was demolished: the lattice is both the structure and the facade. Photo: Ariel.huber, CC BY-SA 3.0, via Wikimedia Commons

Light, climate and services

The frame was the climate system. Rewal told the C20 that the building was a three-dimensional jaali, left open without glass for years, so air moved through it and it needed no air conditioning. The sun hit the outer layer of members while the inner face, 16 ft further in, stayed in shade.

By December 2006, in the photo below, the triangles of the sloping faces held glazing with patterned screens and darker solid panels. We found no dated source on when the hall was enclosed.

Looking up inside the Hall of Nations: a grid of concrete space frame members forms the flat ceiling at the top of the pyramid, with lights hung between the members, while the sloping sides are a triangular lattice filled with glazed panels with patterned screens and darker solid panels — Inside in December 2006: the same concrete members carry the roof and filter the light through the sloping walls. Photo: Ramesh lalwani, CC BY-SA 4.0, via Wikimedia Commons

On services, the sources say little beyond the plan: eight gated openings with facilities beneath the approaches, for exhibits Rewal's office lists as "from books to bulldozers".

Reception, and why the Hall of Nations was demolished

INTACH included it, with the Nehru Pavilion, in a list of 62 modern buildings it forwarded to Delhi's Heritage Conservation Committee (HCC). Museums including MoMA and the Centre Pompidou asked the government to preserve it (The Quint), and the C20 entry records appeals from ARCASIA and the International Union of Architects.

The dated facts, from the Delhi High Court's 2019 judgment, The Hindu's court reports reproduced on Architexturez, and the sources named:

Date	What happened
November 2015	ITPO announces redevelopment of Pragati Maidan into a convention and exhibition centre; the Hall of Nations and Hall of Industries are to go (The Quint).
24 February 2016	The High Court dismisses Rewal's first writ petition, W.P.(C) 1146/2016: pending requests for heritage status cannot stall redevelopment (as recited in the 2019 judgment).
20 April 2017	Justice Sanjeev Sachdeva dismisses W.P.(C) 2731/2017, which asked for the buildings to be declared works of national importance. He relies on the HCC's decision that only buildings over 60 years old qualify (The Hindu, via Architexturez). An INTACH petition was listed for 1 May.
Night of 23 to 24 April 2017	ITPO demolishes the Hall of Nations, the Halls of Industries and the Nehru Pavilion (MoMA; C20). The Quint dates it 25 April.
27 April 2017	A Division Bench of Acting Chief Justice Gita Mittal and Justice Anu Malhotra hears Rewal's appeal; his counsel says he will seek restitution (The Hindu, via Architexturez). The appeal was later disposed of as infructuous.
28 May 2019	Justice Rajiv Sahai Endlaw dismisses Rewal's suit, CS(COMM) 3/2018, which sought reconstruction under Section 57 of the Copyright Act (judgment).
26 July 2023	The new International Exhibition-cum-Convention Centre on the site is inaugurated and named Bharat Mandapam, ahead of the G20 Summit in September 2023 (Outlook).

So, why was it demolished? The owner, ITPO, wanted the land for a larger exhibition and convention centre, and the HCC's 60-year threshold meant the building had no heritage protection. The 2019 judgment found that an architect's moral rights under Section 57 do not let him object to the demolition of a building or claim damages for it. It also said the owners had owed Rewal a duty to tell him in advance and explain their reasons, and had erred in not doing so.

Rewal, Mahendra Raj and others called the demolition an outrage (The Quint).

What designers in India can take from it today

Our reading, from the sources above:

Make the structure do the climate work. The same frame depth carried a 78 m span and shaded the interior. Ask whether a structural layer can also be the shading layer before adding another.
Design for the builders you will get. The precast design was reworked when no contractor would precast to the needed accuracy. Talk to likely contractors before fixing a system.
Bring the engineer in as a co-author. Rewal set the form; Raj made it buildable and redesigned it when the method changed. Involve the structural engineer at concept stage. Rewal's Asian Games Village gets its own case study in this series.
Keep your archive. The building is gone, but drawings at M+, a model at the V&A and the engineering record in a book keep it studied. Document your own work; our case study field checklist shows what to record.

If you are choosing a thesis on exhibition or public buildings, our B.Arch thesis topics by typology lists related briefs.

Seeing the Hall of Nations today

There is nothing left to visit: the site is now Bharat Mandapam. To study the building:

Drawings: M+ in Hong Kong holds five Hall of Nations items from 1970 to 1972: a perspective, a sketch of the shading and sun breakers at the joint, the nine-point joint, a floor plan and sections SD and SG.
Model and print: the V&A in London holds a model of the complex made by Rewal in 2016 for the legal case (E.1-2024), and a presentation screenprint. MoMA notes that other material went to collections including the Centre Pompidou.
Engineering: the chapter on the hall in The Structure: Works of Mahendra Raj (pages 152 to 179), and the Mahendra Raj Consultants project page.

Looking for an architect who thinks about structure and climate together? Find an architect on MOA.

FAQ

Who designed the Hall of Nations in New Delhi?

Raj Rewal was the architect and Mahendra Raj the structural engineer. Mahendra Raj names Puri Construction as the contractor. It opened in 1972 for the Asia 72 trade fair.

When was the Hall of Nations built?

Design began in 1969 or 1970, depending on the source, and the hall was completed in 1972. Sources give the construction time as 15, 18 or 22 months.

Why was the Hall of Nations demolished?

ITPO demolished it in April 2017 to redevelop Pragati Maidan into a new exhibition and convention centre, now Bharat Mandapam. Delhi's Heritage Conservation Committee had not protected it because it was under 60 years old, and the High Court dismissed Rewal's petitions.

What was the Hall of Nations made of?

Reinforced concrete cast in situ, as a double-layer space frame of rhombic members with chamfered edges, used because steel was not available in the quantity needed. The gates were steel.

What were the Hall of Nations dimensions?

Mahendra Raj Consultants give 82 m x 82 m at the base and 27 m high, with about 6,700 sq m of column-free floor. Rewal's office gives a 78 m clear span and an inside height of 3 m to 21 m.

Sources

Raj Rewal Associates: Hall of Nations, Pragati Maidan, New Delhi, 1970 to 1972 (accessed 4 Nov 2026)
Mahendra Raj Consultants: Exhibition halls: Hall of Nations and Halls of Industries (accessed 4 Nov 2026)
Mehta, Mehndiratta and Huber: Drawing no. 101.ITF.55C, Reinforcement layout at levels 1 and 2, from The Structure: Works of Mahendra Raj, 2016, via Architexturez (accessed 4 Nov 2026)
MoMA, Martino Stierli: Remembering the Hall of Nations, New Delhi, 29 August 2017 (accessed 4 Nov 2026)
The Twentieth Century Society, Christopher Turner: Hall of Nations and Nehru Pavilion, Delhi, July 2024 (accessed 4 Nov 2026)
M+: Raj Rewal Drawings and Drawings, Hall of Nations, 1971 to 1972 (accessed 4 Nov 2026)
Victoria and Albert Museum: Model of the Hall of Nations and Halls of Industries complex and presentation screenprint (accessed 4 Nov 2026)
Architexturez, Nirmal Kulkarni: Excerpt from an interview with Ar. Raj Rewal, New Delhi, 27 October 2017 (accessed 4 Nov 2026)
architecture.live, Nirmal Kulkarni: The Hall of Nations: A Lingering Memory, 23 April 2018 (accessed 4 Nov 2026)
architecture.live, Anupriya Saraswat: Stories of the Symbol: discussing the Hall of Nations with Raj Rewal, 9 June 2017 (accessed 4 Nov 2026)
The Quint, Maanvi: Losing a Heritage: A History of Pragati Maidan's Hall of Nations, 26 April 2017 (accessed 4 Nov 2026)
The Hindu, via Architexturez: HC Bench says petition moved by architect Raj Rewal doesn't challenge heritage panel guidelines, April 2017 (accessed 4 Nov 2026)
The Hindu, via Architexturez: Will appeal for restitution of Hall of Nations: Rewal, April 2017 (accessed 4 Nov 2026)
High Court of Delhi: Raj Rewal v Union of India and Ors, CS(COMM) 3/2018, judgment of 28 May 2019, via LiveLaw (accessed 4 Nov 2026)
Outlook: PM Modi unveils IECC complex at Delhi's Pragati Maidan, names it Bharat Mandapam, 26 July 2023 (accessed 4 Nov 2026)