He proposed an innovative "stepped boulevard" arrangement, where buildings would be set at an angle to the line of the street, thus maximizing light into the apartments.

His father, Antoine-Julien Hénard, was a professor of architecture at the École des Beaux-Arts, known as the "architect of the 12th" for his work in the 12th arrondissement of Paris.

[2] During the planning for the Exposition Universelle (1889) Hénard proposed installing an innovative continuous train system to move visitors around, reducing fatigue and improving flow.

[5] The moving sidewalk project was rejected, but Hénard was assigned as a sub-inspector to help oversee construction of the huge Palais des Machines.

[11] Hénard designed the Palace of Electricity for the exposition, at the end of the Champ de Mars facing the Eiffel Tower.

[12] Hénard also designed the Hall of Illusions, a hexagonal structure with a Moorish appearance where the interior walls were covered in mirrors.

[13] For his work on the 1900 exposition Hénard received a gold medal in architecture and was made a knight of the Legion of Honour.

[14] Hénard also worked with various organizations concerned with health, philanthropy or professional services as an expert on urban planning considerations.

[18] Among other innovations he proposed in his Études sur les transformations de Paris were multi-level crossroads, train tracks and metro lines and elevators.

[21] Hénard wanted to develop better radial thoroughfares, and to take the opportunity presented by demolition of the old city fortifications to build a ring road and new parks and housing.

He received strong support from organizations such as the Musée Social, and from other urban planners, but was opposed by real estate investors who feared the impact of his planned 75,000 apartment units.

[21] His diagrams of major cities in Europe where their patterns of radial and ring roads were emphasized were used to support urban plans in the United States, such as those prepared for San Francisco and Chicago by Daniel Burnham.

[20] Hénard proposed various solutions to the problem of efficient traffic flow through road intersections, including a form of cloverleaf interchange.

[25] In urban planning, Eugène Hénard was attached to the idea of combining solutions to practical requirements, particularly those arising from the development of motoring, with aesthetic objectives.

"[26] In the traditional view of sanitation inherited by Baron Haussmann, it was thought that wide, straight tree-lined boulevards cutting through the city would reduce the danger of epidemics by letting healthy air circulate freely.

[34] His streets included conduits for gas, electricity, compressed air, drinking water, pneumatic tubes for letters, telephone lines and so on.

[36] Hénard was the first to propose the concept of an artificial ground level, which influenced later urban architects such as Auguste Perret and Le Corbusier.

[40] However, Hénard presented his innovations within the framework of the contemporary Parisian fin-de-siècle decorative style, while Le Corbusier thought a new urban form would better meet the needs of the new age.

[46][b] Eugene Hénard also proposed to unite the Palais-Royal with the Banque de France headquarters by removing the Rue Radziwill.

[47] For Eugene Hénard, the general circulation of Paris would have benefited from the creation of the new Avenue du Palais-Royal as a "sort of aorta artery placed at the heart of the city, and by its powerful pulsations regularizing the central movement.

"[47] The project also included:[48] For Eugène Hénard, the assembly formed by the arch through the Palais-Royal, the star junction, the square of the Comédie-Française with its fountains and the triumphal arch of the Louvre would create a group of sites in the center of Paris where monumental art would provide additional and undeniable beauty to the city.

In the middle of the square, a large circular funnel 20 metres (66 ft) in diameter would provide light and air to radiating underground pedestrian galleries and the Metropolitan station.

This was supported by the Musée Social, which in 1910 asked citizens to vote in the forthcoming elections for candidates who backed the parkland and urban conservation programs.

[57] Hénard campaigned forcibly to establish "spaces planted with trees, covered with grass and decorated with flowers with a surface at least equal to that of Parc Montsouris".

[59] With sizes that varied from 9 to 12 hectares (22 to 30 acres), the new parks were to be Levallois, Batignolles, Clignancourt, la Villette, Pré-Saint-Gervais, Charonne, Ivry, Vaugiard and Issy.

The purpose of the project was to ensure that every person was at most 1 kilometre (0.62 mi) from a large park and 500 metres (1,600 ft) from a garden or square.

[61] Eugène Hénard stated that in the areas dedicated to sports, the cafes and restaurants that wanted to establish themselves would generate revenue that help cover the costs of developing and operating the parks.