In Vienna, in 1992 the municipality created a new zoning class, “EKLW: a recreational area Kleingarten for all year living”. Wiener Kleingartengesetz (the Viennese Allotment Gardens Act) was then amended so that gardeners could build a larger house in EKLW-type Kleingärten. This study investigates the amendment's influence on the spatial characteristics of Kleingärten focusing on housing renovation. The comparison of traced land use in 2011 with the data of the past study in 1999 demonstrated that EKLW-type Kleingärten actually have larger houses than EKL-type Kleingärten and that the largest variation in house areas were found in the older EKLW-type Kleingärten. The main reasons for this, inferred from interviews with the gardeners, were as follows: that some of small houses built initially for seasonal stays still remain as they have been because the gardeners have used their plots for a long time or have inherited their plots with memories of their family; and that old narrow paths demand extra costs for housing renovations.In contrast, the newer EKLW-type Kleingärten have only houses large enough to live in year round. Thus, both the older and newer EKLW-type Kleingärten are becoming residential places although their speeds are different. Indeed, this housing renovation of EKLW-type Kleingärten has negative effects considering the loss of green spaces inside urban areas. Nevertheless, it can be evaluated positively in that it prevented the release of green belt land and the urban sprawl beyond the Green Belt. Thus, the amendment of Wiener Kleingartengesetz contributed to keep Vienna's urban form compact.