The monumental functionalist building with distinctive neo-classical elements built in 1938-1942 was designed by the architect Milan Babuška, together with the adjacent building of the National Museum of Agriculture, and has highly modern appearance even nowadays. In 2008, the National Technical Museum celebrated the centennial of its founding as well as the seventieth anniversary of the beginning of construction work on the new museum building, as it was not until mid-October 1938, when the construction could finally start after long negotiations.

Dreams of own building
Technical Museum of the Czech Kingdom (after 1918 called The Czechoslovak Technical Museum), was situated in rented premises of the Schwarzenberg Palace in Hradčany from 1909. Since the Renaissance palace could no longer meet the needs, the efforts to build a new building - besides collecting activities – were the Technical Museum Association's most important objective. In 1921, the Financial Committee was founded to gather necessary funds. Another important task was to find a suitable building site. Various parts of Prague were in consideration, e.g. Dejvice, where the new museum building would be built near the Technical University. Another project, made by the architect Alois Čenský in 1924, was to locate the design of the new historicist building in the area of the present-day Trade Fair Palace in Holešovice. In 1925, the Museum Association bought the piece of land between the today's Sparta stadium and Letná water tower. Several projects were designed for this parcel, including a new project by Alois Čenský and others by renowned architects such as Bohumil Hübschmann, Vojtěch Krcha and Ferdinand Fencl.

Partnership with the Czechoslovak Agricultural Museum
In the early 1930s there were not enough funds to start the construction, and so the Association representatives started looking for alternative ways of financing the construction. Finally, a solution was achieved: cooperation with a wealthy, “influential partner with a strong backing." In 1931, the Technical Museum found such a partner in the Czechoslovak Agricultural Museum supported by the Republican Rural Party. Originally, the Technical Museum intended to sell a part of the land near Sparta to the Agricultural Museum (which was originally going to start construction work in Dejvice), and use the gains for funding a joint building in this site. This resulted in close partnership of the two institutions regarding collections and exhibitions. However, such a proposal caused in both museums certain concerns of losing their autonomy, which eventually reduced the ambitious plan to the concept of the building, where the only common spaces were the central building with the vestibule, office facilities, the meeting room and workshops, with exhibition spaces separated.

The Parcel in Kostelní Street and a Public Architectural Competition in 1935
Neither the joint construction of the building could solve the lack of resources in the Technical Museum funds. The Technical Museum decided to sell the land at Belcrediho Street and received its today´s site in Kostelní Street as a donation from government, while the Czechoslovak Agricultural Museum had to purchase the adjacent land. The Sparta site, originally intended for the museum was used for building the famous Molochov residence designed by Josef Havlíček in 1938.
In 1935 financial situation finally allowed to start the construction of the joint museum building. A public architectural competition was opened, there were 41 submitted sketches by various architects, such as Kamil Roškot, Jan Gillar, Bohumil Hübschmann, František M. Černý, Otakar Štěpánek, etc. However, none of the designs met the requirements, so there was no first prize. Two designs were awarded second prize: one by architect Milan Babuška (1884-1953) and one by Ferdinand Fencl (1901-1983), the common project by František Šrámek and Rudolf Vichra and a design by František Tesař were awarded third prize. The authors of awarded designs were invited to take part in a new tender.
After lengthy and complicated negotiations, Babuška´s design of the joint museum building was selected.

The End of the Joint Museum Building Idea
At the end of 1935, the architect in charge of the project was selected to commence the construction work and it seemed that nothing could stand in the way of the initiation of construction, except - as it soon turned up - the way itself, in this case public road No. 741 crossing the building site of the Technical Museum. Official regulatory reasons put an end to the idea of the joint museum building, specifically the Prague authorities' requirement ”to provide the site with an adequate communication instead of the existing public road extending Ovenecká Street". Based on the regulatory plan from 1931, there were supposed to be two buildings in the current location of the two museum buildings. But after the launch of the competition, both sites were unified by the Ministry of Public Works with the approval of the State Regulatory Commission. Only a little later – during the architectural competition for a joint building - Prague authorities demanded the construction of public passage instead of the public road that had originally crossed the piece of land in the Ovenecká Street.. Although this plan seemed feasible at the beginning, it soon became a compelling issue that resulted in temporary suspension of preparatory work on joint building in February 1936. The claim of the public road issue became insolvable, and in addition to its principal role of the joint concept "terminator", it aslo became a “troublemaker” delaying the construction work on the independent building of the Czechoslovak Technical Museum until 1938. The meeting of both institutions' representatives in 1936 showed the regulatory purposes were not the only reasons that brought to an end the ambitious concept of what they called Museum of the Czechoslovak Work. The existence of two separate museums in one "tailored" building had to be abandoned because of disagreements among the representatives (the most important ones were the difference in opinions about the heating, equipment protection, the size and height of rooms, admission issues, not to mention possible economic benefits that museums might have in their own buildings). Besides the close proximity of buildings and their uniform architecture, the new street called Museum street, there are also decent reminders of the original common plans: two corner boards on the east corner of the building of the Agricultural Museum and the western corner of the building of the National Technical Museum. Boards were supposed to be decorated with figurative sculptures and supported by the upper beam of a projected "pergola" above the Museum Street. The Pergola was going to be the last tangible connection between two separate buildings. Even the design of such a connector was gradually about to minimized. On the plaster model of 1937, there was a monumental colonnade with entablature raised to the height of two buildings on the south façade. But the letterhead of Technical Museum already displayed building (yet unfinished at the time) with a significantly lower colonnade. The final reason to reject the design idea was the lack of interest. The best explanation could be found in the statement of the Agricultural Museum representatives to the initiator and promoter of cooperation - the Technical Museum, which in January 1938 suggested that the pergola be raised not on the south, but on the north side of the buildings. The Agricultural Museum responded to this proposal by the rejection of the pergola construction, stating that„in this way pergola totally lacks any purpose and is not therefore sufficiently justified in modern architecture and the similar programme line of the two museums is expressed in the uniform architecture.“

The National Technical Museum Construction
Together with the end of the joint building idea, also the winning project was buried. The Czechoslovak Agricultural Museum addressed the architect Milan Babuška to design a new separated building. The Technical Museum eventually reached the same decision. The long and dramatic process of finding a new architectural design of the two museum buildings began. The architectural style of both building was already determined during the construction of the National Agricultural Museum, which began in 1937, one year before the construction of the National Technical Museum.
Although the decision of separating the buildings was already made in 1936, it took as long as two years to get funding, the building permit and especially to negotiate with former users of land in the Kostelní Street (this consisted of the road originally owned by Prague authorities, and the football pitch owned by Deutscher Fussball Club Prag). The construction work therefore commenced in October 1938, at the beginning of the Second Republic, and a major part of construction work continued in the Protectorate. Despite obstacles such as material savings demonstrated in the implementation of the Directive on Iron Use Reduction, and thus reduction of utility load in the eastern and western wing of the second and the third floor, the shell construction reached the same height of the adjacent buildings of the Agricultural museum. In 1941 the German occupation authorities confiscated the new building under construction as well as the Schwarzenberg Palace, selected as the site for the military museum. In exchange for the two objects the Technical Museum was given the premises in Prague Invaldovna, which was used as a museum depositary for many years until the floods in 2002.

A New Dramatic Chapter in the Museum History
The new building in Letná confiscated by the German occupation authorities was completed to meet the needs of the headquarters of the Protectorate Postal Administration. Limited space continued to be a problem even after the nationalization of the museum in 1951. The Technical Museum had to share the building with many other "tenants" (eg. Ministry of Interior, Geodetic and Cartographic Institute) until 1990.
The architecture of the building has not changed much until the reconstruction in the 21st century, Apart from the granite facade on the bottom of the base made in 1950s. Unfortunately, certain interior details designed by Babuška were not carried out until the recent reconstruction by Ing. Architect Zdeněk Žilka.
Despite the apparent integrity of the building, the original idea was to divide the project into two construction phases, of which only the first one was implemented. The eastern part of the museum site was to be built in the second phase of museum construction that actually never started. In 1940´s Milan Babuška created series of designs for the completion of the second stage, that drew one´s attention particularly by spectacular planetarium. Even later designs, including those from 1957 by architect Bohumír Kozák, remained unrealised. Kozák tried to enrich Babuška´s neo-classical functionalism with a huge side wing and the observatory. Completing of the museum building thus remains a task to be done.