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Introduction to Space Syntax Between the laptop & the pencil Day Two Harvard University Graduate School of Design 12-13th January 2011 Tim Stonor & Ed Parham
Day One Principles & projects A lecture by Tim Stonor Managing Director at Space Syntax Limited Loeb Fellow at Harvard University Honorary Senior Lecturer at University College London. Day Two Between the laptop & the pencil A workshop with Ed Parham Associate Director at Space Syntax Limited Honorary Research Fellow at University College London. Course structure
Course overview Day Two Part One The Laptop Describing space: Axial models Making Processing Analysing Visualising Part Two The Pencil Why use analysis as part of the design process? Urban analysis components Five spatial design components Group exercise: spatial layout generation Part Three The laptop & the pencil The digital analogue feedback
www.spacesyntax.org The website of the Space Syntax Laboratory at University College London. Links to software, publications, international symposia. www.spacesyntax.com The website of Space Syntax Limited, the consulting arm of the Space Syntax Laboratory. Links to case studies, clients, partners. www.spacesyntaxnetwork.wordpress.com A blogsite, bringing together and summarising both academic and commercial practice out of University College London. Space Syntax resources
The laptop Describing space: Axial models Making Processing Analysing Visualising
3 Main types of analysis: Axial/Segment analysis Typically large scale such as cities or masterplans Analyses relationships between street segments Correlates with patterns of movement, land value/use/density distribution, and social/crimes Depthmap is a piece of software which allows spatial systems to be analysed as graphs of relations. Describing space Axial analysis
3 Main types of analysis: Visual Graph Analysis Typically used for public spaces or complex buildings Analyses patterns of isovists (fields of view) from all points within a defined space Correlates with patterns of pedestrian movement, activity and interaction. Depthmap is a piece of software which allows spatial systems to be analysed as graphs of relations. Describing space Visual graph analysis
3 Main types of analysis: Agent Analysis Typically used for complex buildings or masterplans Simulates patterns of movement using isovists and variable sets of origin/destination parameters Depthmap is a piece of software which allows spatial systems to be analysed as graphs of relations. Describing space Agent based analysis
This session will concentrate mainly on Axial/Segment analysis To carry out this type of analysis the first thing we need is an Axial model An Axial model is the first step in translating a set of spaces into a graph which can be analysed. In the graph each node represents a space in the system. Describing space
Axial models can be generated automatically in Depthmap, or drawn manually in Depthmap or CAD. It may be more time consuming but the act of drawing the lines is a useful way to begin to learn about a spatial network. We will make a model of the spatial system below Making an Axial model
Before starting it is important to make sure the model is drawn consistently by following these rules: Draw the least number of lines to cover every space in the system Every line should be as long as possible and connect to the maximum number of other lines Don’t go through buildings Extend the model to a natural break in the urban fabric at least a 30 minute buffer around the site (3km for pedestrians, 15km for vehicles) Making an Axial model
Import the basemap to CAD Making an Axial model
Draw the longest axial lines first… Making an Axial model
Make sure each line passes through as many convex spaces as possible… Making an Axial model
And that all publicly accessible spaces are connected… Making an Axial model
Until the model is complete Making an Axial model
Until the model is complete The model then needs to be exported to a Depthmap compatible format Using a CAD package DXF R12 works best, using a GIS package MIF works best Making an Axial model
Analysing an Axial model We can then start to analyse the model.
Once we have a set of Axial lines, they can be understood as Nodes in a Graph and we can begin to analyse the relationships between them. The graph below is an extract of our Axial model Analysing an Axial model
Every graph can be justified to count the steps to other nodes from any starting point. Analysing an Axial model Depth measures
Every graph can be justified to count the steps to other nodes from any starting point. The shape of the graph changes from each starting point meaning some spaces are closer to all spaces than others Analysing an Axial model Depth measures
We can calculate the total depth of each node by adding the depth to all other nodes If we divide this number by the number of nodes we can calculate the Mean Depth to all other nodes a b c d e f i g h k j j a b c d e f i g h k 1 2 3 4 Total depth from a = 28 Mean depth from a = 2.8 Total depth from g = 20 Mean depth from g – 2.0 MD = 2.8 MD = 2.0 Analysing an Axial model Depth measures
Choice measures work by splitting the axial model into Segments between intersections Analysing an Axial model Choice measures
Choice measures work by splitting the axial model into Segments between intersections Each segment is then treated as an Origin, paired in turn with every other segment as a Destination, and the most direct route between them plotted Origin Destination Analysing an Axial model Choice measures
Choice measures work by splitting the axial model into Segments between intersections Each segment is then treated as an Origin, paired in turn with every other segment as a Destination, and the most direct route between them plotted Origin Destination Analysing an Axial model Choice measures
Choice measures work by splitting the axial model into Segments between intersections Each segment is then treated as an Origin, paired in turn with every other segment as a Destination, and the most direct route between them plotted Origin Destination The number of times each segment is used is counted for all journies with the result that some are used much more than others Analysing an Axial model Choice measures
These are the core principles behind the measures that Depthmap will run. Both can be carried out over multiple scales simultaneously. Origin Destination j a b c d e f i g h k Analysing an Axial model
Open Depthmap 10 Processing an Axial model
Create a new graph file: File > New, or Ctrl+n Processing an Axial model
Import the CAD model: Map > Import, or Ctrl + I (we will use an extract of Boston prepared earlier) Processing an Axial model
Save the Graph file: File > Save Processing an Axial model
Turn the model into an Axial Map: Map > Convert active map > Axial Map Processing an Axial model
Multiple maps can be added to each graph file by repeating the process They will appear in the list on the left and can be navigated between by clicking on Processing an Axial model
Add unlinks where lines are disconnected (such as bridges over highways etc): Make sure the Axial Map is active, Click on Link/Unlink Icon and select lines to disconnect Processing an Axial model
Run Axial graph analysis: Tools > Axial/Convex/Pesh > Run Graph Analysis Processing an Axial model Although this is a necessary step in making a Segment Map, Axial Maps can be processed and analysed too. Axial Map Radii are defined by the number of steps rather than a metric distance, we would typically use 3, 5, 7.
Run Axial graph analysis: Tools > Axial/Convex/Pesh > Run Graph Analysis Processing an Axial model The length of time it takes will increase with model size
Turn the model into Segment map: Map > Convert active map > Segment Map Processing an Axial model
Run Segment analysis: Tools > Segment > Run Segment Analysis Processing an Axial model Check the box to include Choice Always run the radius type as Metric and add the radii you wish to run. Typically we use multiples of 400m as this relates approximately to a 5 minute walk
When processed, the measures will appear in a list on the lower left hand side. Measures can be switched between by clicking on them. Processing an Axial model
When a model is viewed for the first time the colour range will be set to its defaults This means that it may not be possible to see the graph clearly Visualising the results
To adjust the colour range: Window > Colour Range We use Depthmap Classic which puts an inflection in the colour range Use the slider to set the thresholds for the red and blue ends of the scale. This will not change the values in the map but changes how the scale of colours relates to them. Visualising the results
It should look something like this Visualising the results
To look at a Scatter Plot of the graph: Window > Scatter Plot The measure on each axis can be changed Simple statistical analysis such as the correlation between 2 measures can be calculated Visualising the results
New measures can be added to the graph: Attributes > Add Column The measure will appear in the list on the left Adding new measures
To edit the new measure: Attributes > Edit Column Measures already calculated can be used as attributes in a formula by selecting them from the list Sometimes we take the log of a result to understand small distinctions between spaces or combine measures Adding new measures
The pencil Why use analysis in the design process? Useful urban analysis components Five spatial design components Spatial layout generation
Often analysis is seen as preventing creativity in some way. We believe that creative processes should be informed by analysis. If we can identify and define the properties which make something work, and analyse what makes it economically, socially and environmentally successful and sustainable, we can reuse some of these properties. Similarly, if we understand how an area works and what its problems and potentials are, we can synthesise the two together. Why use analysis in the design process?
Urban analysis Location What are the key conditions of a site: Where is it?
What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Log+2 CH RN Urban analysis City wide spatial hierarchy
What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Urban analysis Local scale spatial hierarchy
0 100 200 400 m Congress Street Marrimac Street New Chardon Street Canal Street Friend Street Portland Street Cambridge Street New Sudbury Street Hanover Street Salem Street Tremont Street State Street Union Street North Street New Washington Street John F Fitzgerald Expressway Surface Road Cross Street Prince Street Richmond Street Faneuil Hall Marketplace North Station City Hall Plaza Faneuil Hall Marketplace North Station Haymarket City Hall Plaza What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Where is it busy and when? Urban analysis Movement patterns
0 100 200 400 m Congress Street Marrimac Street New Chardon Street Canal Street Friend Street Portland Street Cambridge Street New Sudbury Street Hanover Street Salem Street Tremont Street State Street Union Street North Street New Washington Street John F Fitzgerald Expressway Surface Road Cross Street Prince Street Richmond Street State Government Center Bowdoin What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Where is it busy and when? Urban analysis Movement patterns
What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Where is it busy and when? North Washington Street Endicott Street Canal Street Congress Street (lower) Friend Street Congress Street (mid) Marrimac Street Cambridge Street Tremont Street New Chardon Street Crossing Hanover Street New Sudbury Street Haymarket Station Government Centre Plaza People per hour [pph] Urban analysis Movement profile
Adults Teenagers & Children Proportion of categories Daily patterns What are the key conditions of a site: Where is it? What is the current spatial hierarchy? Where is it busy and when? Who uses it when? Urban analysis User profile
How do these questions affect a design in terms of: The Location of the site in relation to major land uses? The large scale Linkages it makes? The local scale Layout it proposes? The distribution of Land use? The small scale design of Landscape and Public Realm? How do these components relate to people, the way they move and their activities? 5 core principles of urban design
At the urban scale, we believe there are a core set of spatial components which need to be carefully developed and interact with each other: the Location of the site – what major land uses are nearby and how can the site work with them? the Linkages into the wider network – what is it important to connect to and allow movement to or from? the spatial Layout – where are the streets, public spaces and parks? where is busy, where is quiet? How do vehicles move, is there public transport and where, are any spaces only for pedestrians? Where should urban blocks be bigger or smaller? the Landuse distribution – where are retail, office, residential and mixed uses? How is it distributed through high and low density? Where are secondary uses? the Landscape design – does the smaller scale design coordinate these component? What public realm qualities are important and why? Five spatial design components
We will now carry out a quick exercise to see how analytic information can be used in the generation of design ideas, to show how these principles can be incorporated in the design process, and to show how Depthmap can be used as part of the design process to test and refine proposals. Five spatial design principles
Group exercise Taking the site below purely as a hypothetical exercise, work in groups of 3 – 5 using the information available to develop large scale masterplan concepts. Log+2 CH RN
Group exercise This is meant to be a quick exercise – around 30 minutes. See what happens if you extend streets which connect into the site. Proposals only need to show the key connections, public spaces and urban blocks. Landuses and densities can be labelled on sketches.
Group exercise This is meant to be a quick exercise – around 30 minutes. Sketch designs and do not be afraid to make mistakes or try lots of ideas. Proposals only need to show the key connections, public spaces and urban blocks. Landuses and densities can be labelled on sketches.
Group exercise In around 30 minutes time we will model the proposals and use Depthmap as a performative tool to select the most suitable designs and refine them.
The pencil and the laptop The digital analogue feedback Updating models Developing designs
Why cant we just use an optimisation algorithm to refine the network? Often the constraints on design come from components which are difficult to model – opinions of neighbours, political pressures etc. We could make a model which takes into account these factors, but it would be very slow and resource hungry. The benefit of the Space Syntax model is that it can be adapted and re-run quickly, that it can be translated directly into a design, and that the relationships it analyses are fundamental to the way a city works. The digital analogue feedback
The first thing we need to do is translate the sketch into an axial map. We can do this in two ways – scanning the sketch and modelling in a CAD program, or very quickly adapting the model in depthmap Updating Axial models
To use the scan, first of all save a copy of your existing axial map. Using this as a base we then need to remove the site area. To save time we will also crop the model to a 15km radius from the site. We have this already prepared. Updating Axial models
To use the scan, first of all save a copy of your existing axial map. Using this as a base we then need to remove the site area. To save time we will also crop the model to a 15km radius from the site. We have this already prepared. Updating Axial models
To use the scan, first of all save a copy of your existing axial map. Using this as a base we then need to remove the site area. To save time we will also crop the model to a 15km radius from the site. We have this already prepared. Updating Axial models
To use the scan, first of all save a copy of your existing axial map. Using this as a base we then need to remove the site area. To save time we will also crop the model to a 15km radius from the site. We have this already prepared. Updating Axial models
Now we need to add the sketch design and update the model. Updating Axial models
Try to extend existing lines where possible and remember the earlier rules of drawing an axial map. Draw the longest lines first… Updating Axial models
Make sure all spaces are connected with the least number of longest lines... Updating Axial models
Until the model is complete Updating Axial models
As an alternative to scanning and adapting the model in a CAD package, it can be edited more quickly but less accurately in Depthmap. Use the Axial model Layer in Depthmap and make sure it is editable. Each map can be expanded by clicking the + sign Made editable by clicking the pencil And turned on or off by clicking the eye Updating Axial models
The lines in the Axial Map can now be edited. Clicking on them with the arrow tool will allow you to select them and stretch the lines. Updating Axial models
The lines in the Axial Map can now be edited. Clicking on them with the arrow tool will allow you to select them and stretch the lines. Updating Axial models
Or new lines can be drawn using the Line tool. Updating Axial models
We can then process the model in Depthmap using the same process explained earlier: Make a new graph: File > New Import the DXF: Map > Import Turn it into an Axial Map: Map > Convert Drawing Map, choose Axial Map Add the unlinks: Map > Import, then Tools > Axial/Convex/Pesh > Convert Data Map Points to Unlinks Run the Axial Analysis: Tools > Axial/Convex/Pesh > Run Graph Analysis Turn it into a Segment Map: Map > Convert Active Map, choose Segment Map Run the Segment Analysis: Tools > Segment > Run Segment Analysis, make sure to include choice, use a metric radius and enter the radii you wish to analyse. (This will take around 25 minutes on the cropped model, to reduce the time now we can just process it for local radii (400m and 800m) but remember this will only show us part of the picture.) Adjust the colour ranges and look at the results: Window > Colour Range, choose Depthmap Classic Updating Axial models
Analysing results You should end up with something like this:
You should end up with something like this: Analysing results
You should end up with something like this: Analysing results
You should end up with something like this: Analysing results
You should end up with something like this: Analysing results
You should end up with something like this: Analysing results
You should end up with something like this: Analysing results
And now the difficult bit: What do these patterns mean for the design? Does the design integrate with the surrounding area? What is its impact on the local area? Are land uses in the right place? Are tall or dense buildings in places which are easy to get to? Are public spaces likely to be busy or quiet? What type of character and activity profile is likely to develop? Does this design answer the five spatial principles we started with? If not, change it and re-test it until it does. Developing designs
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