Publications on 19th-century dwelling architecture in Riga so far have been focused on particular periods. But the issue is not yet examined completely. The article deals with Riga city architect (Stadtbaumeister and Stadtarchitekt) Johann Daniel Felsko's contribution to design, construction and reconstruction of dwelling houses from the 1840s to 1880, invoking analogies detected in Riga and Europe. The study is based on unpublished and unknown original projects that are kept in the Latvian State History Archive, the Riga City Construction Board Archive and the Latvian Museum of Architecture. In terms of style Felsko's dwelling houses are mostly close to Neo-classicist principles and decorative elements that were typical of his early period and later were supplemented with a gradual adoption and use of stylistic and spatial options provided by Historicism. In the 1840s when Felsko started his professional career, having completed his studies at Copenhagen Royal Academy of Art, dwelling houses in Riga were designed and constructed according to exemplary facade albums worked out in Russia. Information on projects accepted at that time has survived in the City Construction Board records where the building's measures and construction foremen are specified. This situation is clearly exemplified by Felsko's approval to build a private dwelling house at the corner of Elizabetes and Kalku Streets. During the next decade construction in Riga was significantly affected by the City port blockade caused by the Crimea War. This favoured a total concern with reconstruction of buildings. Several trends are to be singled out. One of them is related to ground floor reconstructions for the benefit of the owner's business activities. In particular cases a partial or complete removal of historical decorative elements has been detected. The second trend meant extension and setting up of conveniences. Wings of buildings designed after exemplary facades were supplemented with a corridor along the width of the building with an entrance door from the street.