City plans can include height step-downs towards mid-and-lower density neighborhoods to lower visual & operational impacts.
Benefits & Problems Addressed
Visual transitions: Height tapering minimizes the visual impacts of taller buildings.
Light & shadows: Careful design and shadow analysis will help prevent problems at the deign stage.
Noise & other impacts: Careful design and high performance building materials can mitigate problems.
Tips & Techniques
Best candidate areas: Height transitions are best implemented where cities target density near areas of lower densities along wide avenues. These areas typically include transit stations, corridor redevelopment, and mixed use centers.
Implementation: Height tapering requirements are best determined within small area plans and implemented via zoning codes. Small area plan studies will establish maximum height(s) & formulae for stepped-down heights form the maximum to the planning area edge that abuts existing neighborhoods.
Shadows: Use shadow & wind studies to assess solar access and potential wind tunnels. Shadow studies take into account building orientation & articulation, building mass, protrusions, porches & balconies, setbacks, slope, time of year, deciduous tree canopy, solar panels. Augmented reality apps will be commonplace, allowing visualization of building design and solar access.
Edge treatments: While step-downs lower some impacts, the border between existing neighborboods and new development should consider impacts from alleys, loading zones, landscaping, and trash collection. In addition, quality design, materials and lighting should consider the interface, especially with residential areas. Rooftops and roofing are more visible with tapering, Consider monitoring the performance of design criteria and site plan conditions.
Shallow lots: Narrow lots constrain the ability for gentle tapering. In these cases, the back of new buildings will likely abut the lot lines with loading, parking and yards in the front,
Hot Buttons: Density is typically a sensitive topic with neighborhoods; waste and trash collection areas that abut residential areas; financing mid-rise buildings.
Resources
Avenues and Mid-Rise Buildings page; Toronto, Ontario Canada
Image: Toronto Planning Department, Canada