The City of Ottawa has adopted two sets of infill zoning regulations affecting 1 to 4 storey residential dwellings. They are summarized below:
Mature Neighbourhoods Overlay (Inner Urban Neighborhoods)
The Mature Neighbourhoods Overlay (Zoning By-law 2012-147) affects dwellings within the inner urban neighbourhoods (Wards 14, 15 and parts of 12, 13 and 17). The Overlay contains regulations intended to recognize the established look along a street. These include regulations on the use of lands in the front and corner side yards including the amount of landscaping, rear lane access, driveway widths and on-site parking, as well as the orientation of the main door, and the minimum amount of habitable floor area required on the first floor, closest to the existing average grade. Flag lot, corner lot, and long semi-detached dwelling developments are introduced and regulated.
A Streetscape Character Analysis is required for development, or an addition in the front, side or corner side yard, or for a private approach, in the area covered by the Mature Neighbourhoods zoning overlay. The guide on how to complete a streetscape character analysis can be found here
Additional information can be found here
Infill II (By-law 2015-228) creates the alternative provisions for Urban Areas in the R1- R4 Zones that affect inner and outer urban wards (Wards 7-18). These regulations affect building height, rear and side yard setbacks, projections above the height limit, including rooftop terraces, projections into required yards, including balconies, patios, etc. The purpose of these rules is to limit building height and mass, privacy issues, sun obstruction, loss of permeable surfaces and soft landscaping to allow for new dwellings and additions that fit in with the established character of the neighbourhood. Sections that govern these areas in the by-law currently are 139, 140 and 144.
Here is a link to sections of the By-law that provide alternative provisions for the Urban Areas.