PRESENTATION OF THE PROJECT – THE STAKES

In 2011, the Gaumont-Pathé group decided to restructure the existing building to improve the quality of itscinemas, as well as to properly address the needs and greeting of customers. The general objective of the groupis to progressively renew the image of its movie theaters, often very urban and installed on magnificent sites butsuffering from a sometimes dated image.

The goal is to make them into beautiful cultural spaces, lively in daytime as much as nighttime and flexibleenough so that they can host a diversified program, mixing Film with other cultural events: the image of the MovieTheater in the City must be totally renewed.

The objective of the Gaumont-Pathé group is thus to inscribe a new page in their theaters’ architecture which willbe contemporary and innovative. The emphasis will be put on a very high quality of comfort, of acoustics andvision in the cinemas themselves, but it will also be put on a very high generosity in terms of reception, hallwayspaces and circulation of the public, before and after the movie.

THE SITE – THE EXISTING BUILDING – HISTORY

SITE AND CONTEXT The Alésia Cinemas are located near a large crossroads: their main facade, fully west-oriented, is facing thesouth part of the General Leclerc Boulevard. The building is composed of seven cinemas and located on arelatively deep parcel with a second façade facing the street of Alésia.The main façade on General Leclerc Boulevard is very large (about 25 meters long), in between two adjoiningbuildings very different from one another: a housing building of 7 floors on the right and a mixed-use building oftwo floors on the left.

HISTORY OF THE BUILDING It is on February 4th, 1921 that opened at this location a temple of film, the “Montrouge-Palace” entirely build inreinforced concrete – very daring at the time – with its magnificent unique main cinema of 2800 seats. In 1930,the firm Gaumont will take over the exploitation.A complete transformation is made in 1951 with a brand new theater that is inaugurated on October 10, 1951: thenew cinema of 2000 seats has a large balcony and will keep its beautiful reinforced concrete arcades. The boxessurrounding the stage will disappear.It is also equipped with a wide screen, in order to adapt to the recent trend of movies filmed in a large format,which will lead to the appearance of the famous “CinemaScope” in 1953.During the sixties, the theater loses its name « Palace » and simply becomes the “Montrouge-Gaumont”.

In 1973, like many others, the large main cinema splits into four and the theater becomes the “Gaumont-Sud”.The cinema 1 (900 seats) is built by extending the former balcony, whereas the cinemas 2 and 3 (400 and 300seats) are located in the former orchestra. The small cinema 4, a new room of 120 seats, is located in the upperstories.In December 1986, a new step in the theater’s life happens with the transition to seven cinemas and especiallywith a new façade, completely blue, with a planetary look and a giant clap.The new cinemas 4, 5 and 6 (100, 150 and 150 seats) are built by amputating the back of cinema 1 (whichcapacity is brought back to 520 seats), the cinemas 2 and 3 remain the same and the cinema 7 corresponds tothe former cinema 4 of the Gaumont-Sud.There is an anecdote concerning this clap: for a few months it used to be animated, but after protests in theneighborhoods caused by the noise created by the opening and closing of the clap it was then decided toimmobilize it.

EXISTING BUILDING OF THE ALESIA MOVIE THEATER

The last renovation goes back to May 26, 2004, with the opening of a new “Gaumont-Alésia” and the completetransformation of all spaces (cinemas, hallways, circulation corridors…) into the new identity of GaumontTheaters signed by designer Christian Lacroix.At this occasion, the theater shows a new facade, more sober than its former one.

Of course, the building’s main entrances are situated on the General Leclerc Boulevard. A secondary exit existson the street of Alésia, but no true walkable path or area is emphasized between those two facades. There is aroom on the ground floor that makes joining those two facades impossible, as well as reduces the spaceconsiderably. The paths towards the seven cinemas are relatively short, but they lack a clear and unique guidingline.

THE ARCHITECTURAL DESIGN

The project is composed of a double objective: - First to stage the cinemas in a way that allows to emphasize their volume, both from outside and from inside thebuilding. - Then to stage the movies, but this time directly onto the façade. Here, it won’t be the volumes of the cinemasthat are expressed, but the movies themselves that will be invited…The facades are coated with a network ofLEDs that will become like a canvas for multiple animations: film teasers, cut-out images, colors and abstractshapes can be imagined to make these facades alive.

In this way, the movie theater is looking to find its place again in the city: inside, the architecture will stage uniqueand spectacular volumes; whereas outside, the architecture will be dressed up in moving images and animationsthat will tell the story of cinema…

AN ASSEMBLY OF INTERWINED CINEMAS

The cinemas are assembled together in the project so that almost each of their volume is visible and identifiable.The content of the project is a type of vertical sculpture, where the rooms intertwine one next to the other in anelaborate puzzle.

All the shapes of the bleachers of the inside of the cinemas will be visible from underneath, in order to formbeautiful stair-like ceilings.

These ceilings will then be extended into the adjacent space, to create foyers partially made of stairs: theaudience is hosted in small amphitheaters which steps go down towards the entrances of the cinemas. These willconstitute “off” projection spaces, additional spaces where once again, film is present and multiple.It looks like the orchestra of the cinemas would come further out of the cinemas perimeters, to continue towelcome the audience in an atmosphere filled with of a halo films and projections…

THE FACADES: PLEATS OF ANIMATED SURFACES

In the urban context of the project, the main façade on the General Leclerc Avenue will play a major role: it islocated right at the exit of the metro Alésia, facing a rather large and generous sidewalk. The authorized height is21 meters on this part of the avenue, whereas the length is about 25 meters. It is then about 500 square metersof façade that rise of this very visible part of the avenue.

In fact the façade is composed of a dozen of vertical threads. Each thread is supporting several facets,successively oriented upwards or downwards.In the center part, those large pleats are glazed and then covered with bars of LED evenly displayed, in order toform a large animated net.On th edges of the façade, the large pleats are opaque and made of a metal cladding, either covered by the samestructure coated in LEDs, or simply pleated to reproduce the rhythm of the LEDs.If the density of LEDs is veryhigh at the center, itbecomes lighter as it getscloser to the edges of thefaçade: the objective is tomake the image (or images)lighter and more blurredgradually as we go furtheraway from the center. Theproject does not aim toincorporate a rectangularscreen, but to show ananimation in a poetic way, oralmost artistic. Thus he barsof LEDs are lighter and endwith the incorporation of justa few LEDs that give theimpression of a light stipplingthat shades off into thepleats of the metal cladding.

The pleats integrate this time discreetly the constraints of the Urban Planning regulations: we do not feel a breachbetween the lower simple part and the upper part of the façade, fractioned by successive retreats. On thecontrary, the project is developed on 12 vertical strips, each following their own pleats. Those pleats can be eitherindependent, to offer a unique image different from the next pleat, or they can form a whole with one imageanimating all the LEDs.The possibilities of animations are multiplied.In the lower part and on its last section, each strip refolds upwards, to form almost horizontal surfaces: thiscreates a large canopy with an overhang of about 3 meters onto the sidewalk. These panels forming the canopyare also covered in LEDs, to offer the audience this time from close by, different animations that they couldalmost touch…The audience will feel like they are “going inside the image” as they enter the building…

During daytime, the project isforemost constituted by thosetwelve strips which go down fromthe roof to become a protective andwelcoming canopy. The visibility ofthe LEDs will be delicate, and as wego along towards the center, theanimations of the LEDs will bebecome more The strongestreadability will be the one of thepleats in the daylight, and that of ametal fabric encircled with a halorom the animated LEDs.

The façade will give a homogenous impression; the folds will be very perceptible. The more one will go towardsthe lower part, the more the led animations will be visible and luminous. The presence of the metal cladding willbe clear and a little shimmering under a somewhat strong natural light in his south-west orientation.

At night, the animated LED will be much brighter. But sowill be the interior of the building, made also luminous bythe amphitheater lights and lights in the circulationspaces. In this way, the LEDs animation will look like itwas created on a translucent filter. This double vision,superimposing both the screens of LEDs and thebuilding’s interior spaces will give the project a uniquepresence on the square of Alésia.

Generally, the perception of the façade will happen mainly from theoutside, but it can also be very important from inside the building.The different paths to the cinemas, the foyers, walkways, generousbleachers, are all paths that can highlight the façade and allow allpublics to discover it, from backwards. And it will be just as beautifula facade from the inside: made of large windows protected by a netof LEDs, it will offer a view of the boulevard from above, of thechurch across the street, but also of the sophisticated work of theled bars steadily attached in the metal fabric.At dusk, the light of the LEDs will be slightly visible from inside thebuilding, creating halos of light in the circulation spaces and foyers.

The dense implementation of LEDs bars will also play a role of sun visor on this slightly sunny façade. The solarand heat supplies (because the sun-visor is outside) will be diminished.The façade on Alésia Street will be of equal importance in the project, because it will also be an entrance to themovie theater contrary to the current organization of the building. The wish is to make this theater more visibleand welcoming in the neighborhood and this entrance on the Alésia Street is therefore essential.This façade offers variations of the concept imagined on General Leclerc Boulevard, but in a much more discreetway. Its size, smaller, allows the activation of a small animated surface made of some pleats in the strips.

WELCOMING THE PUBLIC

As mentioned above, the wish was to make the project more fluid and more accessible to all types of audiences.The entrance into the space is made through a hallway that extends from one side of the building to the other,from Général Leclerc Boulevard to Alésia Street.In this wide, light and open space, all the functions of reception are installed: in the first part coming from theboulevard is the ticket office, the information desk, the ticket machines and information points and the snacks anddrinks shop including a coffee and leisure space. A little further on the left are situated different paths toward theentrances of the cinemas, upstairs and downstairs, and further again, towards Alésia Street is situated a calmerspace, where one can watch teasers or films.

If one wishes to go to one of the cinemas in the upper-story, they go through a game of footbridges, walkwaysand escalators that takes you on different mezzanines at the right angle of the façade. In fact, the space ismajestic because it is a three heights atrium, connecting all the circulations together. The publics can see eachother, discover the space underneath them or above them, discover the view on the street…In the middle of this game of stairs, footbridges and escalators, wide bleachers are installed: they are facing theentrance of the cinemas and punctuate the promenade of the public. These bleachers are yet another place formeetings, encounters and for taking a break before entering the cinema.The slope of the stairs is going down towards the entrance wall to the cinemas, which allows imagining numerousprojections on this wall, that you can discover standing or seating on the stairs. A first taste of the chosen moviefor instance.

TECHNICAL ASPECTS

A LIGHT FAÇADE SUPPORTING THE LEDS

General display of the façade

The main façade, on the General Leclerc Avenue, is almost entirely made of glass. Behind the façade are locatedseveral walkways that allow the audience to enter the cinemas. The façade creates a connection, both ways,between the street and the audience going to the movies, may they be entering or leaving the cinemas or simplywaiting in the walkways.

A façade like a cascade of pleated strips

The façade is cut into a series of vertical strips. Each strip is composed of a series of inclined planes that zigzagsdown along the façade. In the lower part of the façade, those strips go beneath the entrance gates where they arefolded towards the exterior to form a large glass canopy above the sidewalk.

A curtain wall made of steel

The structure of the façade is composed of rectangular steel profiles that take support on the walkways situatedbehind the façade, onto which they transfer the wind pressure. However, as the walkways have low verticalinertia, all the vertical charges of the façade are brought back to the ground at the street level. In the upper part,the structure turns over to become the framework structure of the roof. The rectangular profiles are then replacedby hot-rolled profiles, hidden behind a suspended ceiling. The horizontal stability of the roof structure is insuredby crossed braces, and the stability of the façade is insured by an action in Vierendeel to make sure that thestructure can work in Vierendeel, and that the connections are embedded properly.Entire portions of the façade’s grid will be pre-fabricated with weld connections, in units of transportable size.The mounts of the façade are doubled when there is a variation of level or when two strips are out of level on thefaçade. The exposed side of the mount is coated and insulated in order to avoid thermal bridges caused by thenon-alignment of the mounts.

The filling panels

The façade is made of very large units and of glazed panels of large dimensions (from 1,70 meters wide and upto 4,7 meters height.) The glass is double glazing with a solar layer. The use of the large glazed panels reducesthe thermal loss of the building since the losses around the joints of a curtain wall are more important than thelosses through a high quality glazing. Consequently, by reducing the linear quantity of joints, we increase the Uvalue of the façade. The LEDs placed on the exterior of the window allow creating a sun visor and reduce thesolar supplies.The opaque parts are either composed of opaque and insulated filling panels inserted in the curtain wall, or madeof cladding panels situated at the exterior of the insulating material on a concrete wall. The opening parts of thefaçade (firemen façade) are located in the opaque areas.

LED supports

The U-shaped bars that support the LEDs are attached to frames made with steel rectangular profiles. To allowaccess to the back of the LEDs (to clean the windows for instance), one panel out of two can slide behind theneighboring panel. Consequently, the LEDs are displayed on two planes that are organized in vertical stripes,with one stripe slightly protruding from the other. The sliding panels are mounted on rails.

A PIXEL CURTAIN FOR THE FAÇADE

The facade of the project was the object of a specific conception, between a luminous installation and a digitalskin. More than 60 000 light points, displayed on 12 meters height and 19 meters width and independentlycontrolled, allow the diffusion of images and luminous atmospheres on the Général Leclerc Avenue.The support, a metal cladding placed in front of a large window, was the main technical challenge, but in fact alsoa major attraction. Indeed, the nocturnal perception of the bright interior of the building and, superimposed, amovie teaser or poster, points out the Alésia theaters in a singular and attractive way in the neighborhood, like acurtain of pixels. The canopy covering the main entrance continues this display process, with the possibility toshow information related to the number of visitors.

The luminous sources in LED were designed to be as functional in daytime or nighttime, by adjusting theintensity. Their gap or “pitch” leaves empty spaces that the eye can perceive as one comes closer to the entrancegate. This intentional optical effect also allows offering a different urban image depending on the point of view,from a clear-cut vision to a pixel mosaic.

REFINED ACOUSTICS:

The usual acoustics problems in movie theaters come from the necessity to strongly isolate the cinemas frominterior and exterior noises, to minimize the noise of technical equipment, and to ensure an internal sound that ismuffled enough to allow the restitution without color of movie soundtracks.The acoustic characteristics of cinemas are determined based on the reference guide “French CinemaRegulations” established by the technical commission for image and sound.

The project of the movie theater Alésia presents multiple specificities that imply additional acoustic issues and anincreased complexity. Partly thereof:

 Multiple adjoining housing buildings, that should properly be protected from high sound levels that will begenerated in the cinemas;  A mixt structure made of concrete and a metallic framework, which induces us to find comprehensivesolutions for each case.  The will of the client to be able to offer amongst the 8 cinemas of the future theater, some cinemasequipped with a system of sound immersion (3D audio system).

The necessary preservation of the perimeter walls of the existing building, onto which the future structure willpunctually lean on, constitutes another major constraint on the acoustic level, because it will introduce noise andvibrations transmission paths towards third parties.To soundproof the cinemas from each other and from the residents in regards to the given constraints, we haveminimized as much as possible the structural bearing points. Also, it was anticipated to use principles of doubleand self-supporting soundproofing on the walls of the rooms, in the ceilings (suspended soundproof ceilings onsuspension springs), but also on the floor (false floor and broken-away rows of seats on anti-vibration mounts).Concerning the internal acoustic atmosphere of the cinemas, it must be specifically meticulous in order to allow atruthful reproduction of the soundtrack and to avoid parasites and echo phenomena.

We must distinguish the common cinemas from the cinemas where immersive audio diffusion is planned. In thefirst case, the absorbing acoustic treatments considered have been tested many times. In the second case, theinnovative choice of an immersive diffusion in cinemas 3, 5 and 8 is specific because this process includes theinvolvement of a large number of additional speakers on the ceilings and on the walls, compared to a standarddiffusion. In this way, it allows to offer an optimum spatial diffusion of sound and a feeling of being immersed intothe sound action of the films.

A MIXED STRUCTURE

The restructuring operation of the Gaumont Alésia movie theater will start with partial deconstruction works andstructural works allowing completing, within a first phase realized conjointly with the waterproofing and façadeworks, the core and shell of the building.These deconstruction works and structural works will be done in a context that has a high level of constraints, onregulatory, technical, programmatic, architectural and operational levels.

The technical constraints are the result of numerous factors:

- Site constraints, including the presence in the parcel’s subsoil of a former extraction quarry for limestoneexploitation that will need to be reinforced, - The constriction of the construction work zone inside the preserved facades strongly cluttered up by thestabilization apparatus holding from inside and outside those facades until full completion of the permanentsuperstructure of the building, - The programmatic imposition to realize eight cinemas for a total number of about 1400 seats, thus makingobligatory the reduction of the size of the structures and their acoustic, thermal and secondary additions to theminimum, -The necessity to set up an entrance hall and foyers offering a high quality of space in the residual volumesremaining after the implantation of the eight cinemas and the technical and administrative facilities.

The construction works then include, after the preceding phases of clearing and asbestos removal works in theexisting buildings:

1/ a phase of reinforcing the quarry, and the realization of perimeter walls as a retaining infrastructure, 2/ the realization of the reinforced concrete frameworks of the infrastructures, including the vertical and horizontalpanels in rooms 1 to 4, 3/ the realization of the reinforced concrete frameworks of the superstructures, including the vertical circulations,the surrounding inclined reinforcement panels in rooms 5, 6 and 7 leaning against the party-walls, 4/ the realization of the steel frameworks conceived to lighten the building reduce the impact of the structures andallow a fast implementation, while minimizing the construction work’s nuisance.

These structures make an indivisible power set, relying on a minimum number of load-bearing points at the angleof the surrounding walls, and on a simple line of tubular poles, made of both steel and concrete, doubling theglazing façade without impeding the free space of the entrance hallway and of the foyers in the levels L2 to L4.Apart from the strip of walkways surrounding the façade on Avenue Général Leclerc that rests upon this line ofpoles, the remaining reinforcement walls and floors of the foyers and cinemas will transfer their charge throughthe intermediary of two master beams, crossing the width of the building without any further support, which willcome rest upon the surrounding reinforcement walls at the north and south of the building.

Those beams, place at the rear of cinemas 6 and 7 for one, and 8 for the other, will be subjected to the impact ofmany openings (double-door entrance to the cinemas, control rooms, underground escalator passageways,networks) ; consequently they are designed and calculated in Vierendeel beam for one and the other one as abeam truss, and will require a specific study of implementation, through means of mobile and exceptional liftingdevices requiring special authorizations from the City services.All these structures will be fireproof, either through the use of pasty products, or through the use of intumescentpaint in the case of the visible structures (including the mixt poles).