Christopher Alexander's "A Pattern Language" (1977) proposed no residential buildings over 4 stories, due mainly to psychological reasons. I believe he also preferred walkable cities.
>Embodied GHG arguments are being used to fight the demolition
>and replacement of perfectly good existing buildings. But are they
>being used to cut storeys off proposed buildings?
>I have never heard of that.
Well, it wasn't successful, but I made that argument at Toronto and East York Community Council this past summer to try to get floors removed from a development on at 1251-1311 Yonge St, south of St Clair.
Really appreciate this ongoing inquiry. Adding a wrinkle: I've heard the argument that considering household emissions, building taller can result in less household emissions when it is near mass transit and helps create vibrant mixed-use walkable neighborhoods, especially when it has no parking. In this view the upfront and operational carbon of such buildings of any size are outweighed by reduced transportation emissions and taller is better. I find no studies explicitly focused on this balance, but articles like the following and its cited research describe the basic approach: https://www.nytimes.com/interactive/2022/12/13/climate/climate-footprint-map-neighborhood.html. Lloyd- it would be very interesting to hear your view on this angle.
I'd like to see that too. Each additional unit within the city has the potential to create a cascade of commute changes, replacing a long solo car drive from the exurbs with a short transit, bike, or walk
In small doses, towers are inspiring. Height has its place - as occasional spires or
domes on churches and civic buildings that punctuate the skyline, or lookout towers for
defense or amusement, etc.
However, years of experience have shown us the problems with towers:
– increased safe exit risk and limited means of escape due to height
– steals energy from all the buildings it shades in the quarter or increases heat load
from reflected solar onto neighbors
- steals daylight and sunlight from the common urban areas like parks and streets
– steals views from existing buildings
– acts as a vertical-gated community, cut off from the neighbors
– social exclusion via separate entry for the social housing component
– psychological effects on residents, difficult supervision of children after 4 floors
– economics of tall buildings work to the detriment of small-scale entrepreneurial
activity, and can fuel gentrification as well as demolition of historic structures.
– increasingly high embodied energy with increasing height
– net rentable area reduces due to fixed services area (elevators, fire escapes, ducts,
risers, soil stacks…)
– very difficult to achieve very low energy use buildings or renewable on-site production
– dis economies of vertical construction systems
– challenges of operable windows and ventilation above 30 stories
– challenge of maintenance and repair of the exterior
– investment vehicle for international money looking for a “luxury” home that often leads
buildings half empty and apartments totally unaffordable for the “locals”
– implies expensive nodal, heavy rail public transport (thus high- density tall buildings
around stations) rather than distributed lower cost surface mass transit trams Problems with Towers - John Daglish
In small doses, towers are inspiring. Height has its place - as occasional spires or
domes on churches and civic buildings that punctuate the skyline, or lookout towers for
defense or amusement, etc.
However, years of experience have shown us the problems with towers:
– increased safe exit risk and limited means of escape due to height
– steals energy from all the buildings it shades in the quarter or increases heat load
from reflected solar on neighbors
- steals daylight and sunlight from the common urban areas like parks and streets
– steals views from exiting buildings
– acts as a vertical-gated community, cut off from the neighbors
– social exclusion via separate entry for the social housing component
– psychological effects on residents, difficult supervision of children after 4 floors
– economics of tall buildings work to the detriment of small-scale entrepreneurial
activity, and can fuel gentrification as well as demolition of historic structures.
– increasingly high embodied energy with increasing height
– net rentable area reduces due to fixed services area (elevators, fire escapes, ducts,
risers, soil stacks…)
– very difficult to achieve very low energy use buildings or renewable on-site production
– dis economies of vertical construction systems
– challenges of operable windows and ventilation above 30 stories
– challenge of maintenance and repair of the exterior
– investment vehicle for international money looking for a “luxury” home that often leads
buildings half empty and apartments totally unaffordable for the “locals”
– implies expensive nodal, heavy rail public transport (thus high- density tall buildings
around stations) rather than distributed density lower cost surface mass transit trams
Alternative typologies and design codes (missing middle) such as terraces, townhouses, mews houses,mansion blocks, etc of maximum 5 to 6 stories can achieve sufficient densities that with
surface transit (streetcars), sufficient park space, public amenities can achieve a quality
built environment with a good environmental outcome.
The not too large “flat” European city can be serviced with streetcars rather than
expensive heavy train systems (under or overground) that encourage peak densities
(and tall buildings) around stations to economically justify their high infrastructure cost.
This local traditional pattern that arrived after centuries of urbanism can be replicated - if
local zoning regulations allow it.
Most cities seem to be a mix of emergent (unplanned… picturesque) and the formal
interventions (planned … but not necessarily symmetric).
Exellent take on this. Hoffer's finding that slab thickness matters more than height feels like classic reductionism, isolating one variable while ignoring the cascade of design choices that unlock at lower scales. When I worked on a mid-rise retrofit, we had way more flexibilty with timber and natural ventilation than we ever would've in a tower. Seems like the real insight here is optimization matters everywhere, not that height doesnt.
Does this analysis consider how many elevators are needed for increasing the number of floors? If a five story building has one elevator, does a twenty story building still only need one? Once you need more elevator shafts, you lose useful space. The number of elevators depends on use. Office space will have many more people using it than a residential building, so an office building requires more elevators.
And isn't slab thickness a function of intended use? Residential allows for more columns than commercial, so residential slabs can be thinner because spans are shorter.
Christopher Alexander's "A Pattern Language" (1977) proposed no residential buildings over 4 stories, due mainly to psychological reasons. I believe he also preferred walkable cities.
>Embodied GHG arguments are being used to fight the demolition
>and replacement of perfectly good existing buildings. But are they
>being used to cut storeys off proposed buildings?
>I have never heard of that.
Well, it wasn't successful, but I made that argument at Toronto and East York Community Council this past summer to try to get floors removed from a development on at 1251-1311 Yonge St, south of St Clair.
Really appreciate this ongoing inquiry. Adding a wrinkle: I've heard the argument that considering household emissions, building taller can result in less household emissions when it is near mass transit and helps create vibrant mixed-use walkable neighborhoods, especially when it has no parking. In this view the upfront and operational carbon of such buildings of any size are outweighed by reduced transportation emissions and taller is better. I find no studies explicitly focused on this balance, but articles like the following and its cited research describe the basic approach: https://www.nytimes.com/interactive/2022/12/13/climate/climate-footprint-map-neighborhood.html. Lloyd- it would be very interesting to hear your view on this angle.
I have to agree, how does this affect the "walkable cities" idea?
I'd like to see that too. Each additional unit within the city has the potential to create a cascade of commute changes, replacing a long solo car drive from the exurbs with a short transit, bike, or walk
Problems with Towers
In small doses, towers are inspiring. Height has its place - as occasional spires or
domes on churches and civic buildings that punctuate the skyline, or lookout towers for
defense or amusement, etc.
However, years of experience have shown us the problems with towers:
– increased safe exit risk and limited means of escape due to height
– steals energy from all the buildings it shades in the quarter or increases heat load
from reflected solar onto neighbors
- steals daylight and sunlight from the common urban areas like parks and streets
– steals views from existing buildings
– acts as a vertical-gated community, cut off from the neighbors
– social exclusion via separate entry for the social housing component
– psychological effects on residents, difficult supervision of children after 4 floors
– economics of tall buildings work to the detriment of small-scale entrepreneurial
activity, and can fuel gentrification as well as demolition of historic structures.
– increasingly high embodied energy with increasing height
– net rentable area reduces due to fixed services area (elevators, fire escapes, ducts,
risers, soil stacks…)
– very difficult to achieve very low energy use buildings or renewable on-site production
– dis economies of vertical construction systems
– challenges of operable windows and ventilation above 30 stories
– challenge of maintenance and repair of the exterior
– investment vehicle for international money looking for a “luxury” home that often leads
buildings half empty and apartments totally unaffordable for the “locals”
– implies expensive nodal, heavy rail public transport (thus high- density tall buildings
around stations) rather than distributed lower cost surface mass transit trams Problems with Towers - John Daglish
In small doses, towers are inspiring. Height has its place - as occasional spires or
domes on churches and civic buildings that punctuate the skyline, or lookout towers for
defense or amusement, etc.
However, years of experience have shown us the problems with towers:
– increased safe exit risk and limited means of escape due to height
– steals energy from all the buildings it shades in the quarter or increases heat load
from reflected solar on neighbors
- steals daylight and sunlight from the common urban areas like parks and streets
– steals views from exiting buildings
– acts as a vertical-gated community, cut off from the neighbors
– social exclusion via separate entry for the social housing component
– psychological effects on residents, difficult supervision of children after 4 floors
– economics of tall buildings work to the detriment of small-scale entrepreneurial
activity, and can fuel gentrification as well as demolition of historic structures.
– increasingly high embodied energy with increasing height
– net rentable area reduces due to fixed services area (elevators, fire escapes, ducts,
risers, soil stacks…)
– very difficult to achieve very low energy use buildings or renewable on-site production
– dis economies of vertical construction systems
– challenges of operable windows and ventilation above 30 stories
– challenge of maintenance and repair of the exterior
– investment vehicle for international money looking for a “luxury” home that often leads
buildings half empty and apartments totally unaffordable for the “locals”
– implies expensive nodal, heavy rail public transport (thus high- density tall buildings
around stations) rather than distributed density lower cost surface mass transit trams
Alternative typologies and design codes (missing middle) such as terraces, townhouses, mews houses,mansion blocks, etc of maximum 5 to 6 stories can achieve sufficient densities that with
surface transit (streetcars), sufficient park space, public amenities can achieve a quality
built environment with a good environmental outcome.
The not too large “flat” European city can be serviced with streetcars rather than
expensive heavy train systems (under or overground) that encourage peak densities
(and tall buildings) around stations to economically justify their high infrastructure cost.
This local traditional pattern that arrived after centuries of urbanism can be replicated - if
local zoning regulations allow it.
Most cities seem to be a mix of emergent (unplanned… picturesque) and the formal
interventions (planned … but not necessarily symmetric).
Watch Patrick Condon - The flat city: https://www.youtube.com/watch?v=E0BPYmE1xhk
Visit very/ultra light trams and tracks :
- https://trampower.co.uk
- https://www.coventry.gov.uk/coventry-light-rail
- https://tig-m.com/
Exellent take on this. Hoffer's finding that slab thickness matters more than height feels like classic reductionism, isolating one variable while ignoring the cascade of design choices that unlock at lower scales. When I worked on a mid-rise retrofit, we had way more flexibilty with timber and natural ventilation than we ever would've in a tower. Seems like the real insight here is optimization matters everywhere, not that height doesnt.
Does this analysis consider how many elevators are needed for increasing the number of floors? If a five story building has one elevator, does a twenty story building still only need one? Once you need more elevator shafts, you lose useful space. The number of elevators depends on use. Office space will have many more people using it than a residential building, so an office building requires more elevators.
And isn't slab thickness a function of intended use? Residential allows for more columns than commercial, so residential slabs can be thinner because spans are shorter.