The building as well as its artistic decor was designed by František Roith (1876–1942). The austere neoclassical facade of the large building, adorned only with a balcony with six allegorical figures by Ladislav Kofránek, hid a modern and for its time an excellently equipped multi-purpose space.
Beside the municipal library itself there are the library for young readers, library for visually impaired and library for municipal employees, the building also housed two lecture halls, halls for a picture gallery of the Patriotic Society of the Friends of Art, space for Říše Loutek puppet theatre, rooms designed for Antonín Sova Museum and offices for the Municipal Statistical Office.
The interior of the building was conceived in a more ornamental way than the exterior. It combines elements of late Art Nouveau with a strong influence of the fashionable Czech Art Deco of the 1920’s.
The Mayor’s Residence occupies the whole of the first and second floor of the front part of the library. It has a separate entrance from the corner of Platnéřská and Žatecká Street. The first floor contains representative and a reception room, the second floor contains the Mayor’s private apartment, private study and three apartments for the Mayor’s guests.
When decorating the residence, František Roith co-operated with František Kysela, the author of the paintings on the ceiling, carpets, tapestries, upholstery and textile wall covers, Josef Sejpka, who co-operated on the decorative room painting, Emilie Paličková, who made the curtains and lace accessories. Sculptures and decorative accessories are the work of the sculptor Karel Štipla and the painters František Kysela and Josef Sejpka.
The furnishing and decorating of the Mayor’s Residence was completed in 1930. The large tapestry called Work, Science and Art, designed by František Kysela was not put up until 1932.
The representative space of the residence and the apartment contain sculptures by Břetislav Benda, Karel Štipl and Vilím Amort, ceramic works by Helena Johnová and paintings by thirty leading Czech and foreign painters of the 20th century (e.g. H. Boettinger, C. Bouda, O. Bubeníček, K. Holan, O. Matoušek, J. Šetelík, J. Ullamann, A. Weisner, J. Skrbek, O. Hůrka, M. Holý, T. F. Šimon, S. Felkl, O. Homoláč, B. Dvořák, V. Radimský, F. Kavan.). There are also examples of bookbinding and other decorative objects (vases, small statues, porcelain) that the Mayors of Prague received as gifts from prominent personalities and delegations both domestic and foreign cities.
Out of all the Mayors, only Karel Baxa occupied the new official residence, (in office from 1919 to1937). All the other Mayors until present use it only formally. However, the residence has regularly served to accommodate official foreign visits and most of all for protocol and representative purposes.
The importance of the residence and the representative space in the building of the Municipal Library increased after the Old Town Hall was damaged and partially destroyed during the Prague Uprising (8th May 1945). Even after the ceremonial functions of Brožík Hall and the Old Senate had been restored, the Mayor’s Residence in the Municipal Library permanently remained a place of official and representative acts organized by the Mayors of Prague and other supreme organs of the city’s self-government.
From 1994 to 1995, the Mayor’s Residence underwent a general renovation, including a delicate renovation of all the artistic decorations and a necessary modernization of the technical equipment.