Sama Negm- AUC - ARCH 473/3522

Student Portfolio

The American University in Cairo (AUC)

School of Sciences and Engineering - Department of Architecture

ARCH 473/3522 - Digital Design Studio and Workshop (Spring 2019)

Student portfolio documenting samples of work submitted along the course, including research, experimentation, 3D modeling, digital fabrication, parametric design and modeling, physical model realisation and analysis.

Student name: Sama Negm Student ID: 900192102

© The American University in Cairo (AUC), September 2022

Sama Negm Architecture Student

My name is Sama Negm and i am taking this course a senior in Architectural Engineering. I chose to study architecture because it is a mix between art and engineering. Having the ability to create and play around with designs makes the work interesting however i also like that architecture has guides and principles and technicalities which allows me to be more focused.

Digital design is a field which challenges me but it was so interesting to find out all the possibilities and new design techniques that can come out of it. What i found most interesting about digital design is how efficient it can be once you get the hang of it.

Experimenation of the flow and creases that flexible fabric create so as to solidify a dynamic motion into a static form.

Material Exploration

Horizontal draping fabric forming method conducted by student group in UCLA: David Vuong, Yuna Kubota, Ivan Rodriguez,& Sheena Olimpo

Fabric Formwork Research

What is Casting?

Casting in general is when a forming material such as concrete is poured in a solid mold of a particular shape. This can be an existing solid form such as a bowl or the form can be created such as by wooden sticks to make a box.

What is Fabric Forming?

Fabric formwork is the use of textile materials as the shaping instrument for curing concrete. In normal concrete casting, solid boarding is used for the formwork whereas the common textile used for fabric formwork is a plastic geotextile. Other flexible materials can also be used.

When the textile shape is filled with the concrete mix it adopts the most efficient form possible, since the textile can only carry forces effectively through tension (the material is very flexible and may deflect under the strain of fresh concrete, unlike typical formwork). Thus, varying the amount of fabric at any particular point in the formwork gives the opportunity for engineers and architects to explore new degrees of efficiency of construction as well as new aesthetic possibilities.

Essentially, in fabric forming the qualities and shapes of a particular fabric, such as the texture and folds are what is used in creating the solid form and provide very interesting and non typical forms.

Using fabric to create forms has been an idea adopted by several designers/engineers in the past. Some of who pioneered it were the Centre for Architectural Structures and Technology (CAST) and Heinz Isler, a Swiss engineer who used it as part of his work developing very thin concrete building shells.

Fabric Formwork Research

Smocking:

Smoking is one of the fabric forming techniques. Smmocking is an embroidery technique that helps creates 3D forms from connecting points on a 2D fabric. Hand smocking typically involves marking a regular grid onto the sheet of material to tailor, and connecting the end points of pattern lines where excess material needs to be gathered.

Reflection:

A noticable feature in smocking and a lot of general fabric formwork results is that the form has many interesting creases. These creases sometimes look purposefully formed and other times it is the natural movement of the fluid concrete within the fabric.

I am inspired by the natural flow and creases made by fabric which i will be experimenting with in my project.

Final outcome top and bottom surfaces:

Experiment 1 1 2 3 4

Materials used for support are a stand, wooden sticks and plasticine blocks

A plastic material is supported and given shape using sticks and the blocks. It is crumpled to give creases in the form.

Gypsum mixed with water with ratio 3:2 is added.

Another plastic crumpled sheet added on top for further texture.

Approach:

Use plastic bags to create texture on the surface and movement of the form.

Experiment on creating surface perforations for light penetration.

Final Outcome:

The plastic texture created creases with no shape or pattern on one side so it did not look good from that side. The support gave it a dynamic flow. The gypsum was very flaky and would break off

Plasticine blocks support vertical wooden sticks which will support the model made of fabric.

The fabric is dipped in gypsum and supported on the wooden sticks

Top view of model while drying. Due to heaviness of gypsum, the fabric did not lay as expected.

Final outcome side and top view.

Approach:

Solidifying an existing flexible fabric into a dynamic form.

Material Used: • Fabric • Wood Sticks • Plasticine Blocks

Gypsum Ratio: 2:3

Final Outcome:

It gave an interesting flow to the fabric. If stronger supports were used, the shape of the fabric could have been controlled more.

Experiment 3

1 2 3

Placing smooth rocks inside a fabric mold so that form molds around them.

When poured it produced an odd shape so I added more rocks on surface to create further texture.

It failed because the rocks got stuck inside the gypsum due to them not being close enough: gypsum moved between gaps.

Approach:

Using flexible fabric as a mold to hold the model.

using rocks to create texture / pattern on the surface and large perforations through the model.

Material Used:

• Fabric

• Rocks

• Oil Gypsum Ratio: 2:3

Final Outcome:

Failed: Could not remove rocks because they were stuck between the dried gypsum; Had to break it apart.

Reflection

I was able to understand and extract the different variables that affect the outcome. These variables can be controlled in further experimentation.

Variables:

• Gypsum Mix Ratio

• Position of supports

• Surface heights

• Thickness

• Degree of scrunching

• Perforation size

• Perforation position

• Perforation Quantity

I learned that if the mold is very flexible and loose (e.g. plastic bag) then it needs to be supported very well in order to give a desired shape since gypsum can move into any crevice; any fault in the shape of the mold will affect the shape of the model.

Experiment 1 - Development

More plasticine used to make more rig- Creating central core and and forming the plastic around the bulks.

Gypsum Ratio: 1:2

Smoother, more balanced creases than intitial experiment due to use of single piece of plastic on both surfaces.

Perforations breaking open on each other - different sizes formed. Interesting shadows.

Varying surface heights on both sides – more flow.

Better overall shape due to more rigid form.

Parametric Building Block

16 Translation of Experimentation into Parameters

Outline: Semi organic – squarish circle General shape of unit

Centre: Creases lead to center point Main focus of perforation(s)

Curves: Flow between curves creates a surface with creases

Curve Points: Dynamic and varied flow of the different curves – create different crease shapes and sharpness

Perforation(s): Focused around center of the unit

Circular or organic shape

Heights:

Varied to create a flow of shape with one side being higher – like a wave.

Controlled by changing heights of curve points.

Highlighted features of the experimentation model:

Grasshopper and Rhino

Drawing organic square outline shape on Rhino. Give more circular form by fillet.

Offset curves to create different heights Changing Offset distance Changes center hole size

Divide Offset Curves into Points to control heights. Use Random and Construct Domain components to move the curve points.

Can control Domain, Seed, and No. of Points to change the flow and shape of creases.

Grasshopper and Rhino

Use Nurbs Curve to make new curved lines connecting the random points.

Loft the Curves to create Surface. Can now see the creases.

Extrude the surface to create a block with a (controllable) thickness.

Render the block with a light color.

Use Solid Difference to cut out organic circular perforations. Decrease in size as they move closer to edge.

20 Single Panel Variations

Decrease offset step – increases centre hole size

Could change in façade to control amount of sunlight

Increase fillet radius for panel outline

Remove perforations except center – increase solid to void ratio

Increase / decrease number of points on the curves

Change Seed of the random command moving the curve points

Keep constant in cluster for practicality in façade construction and ability to overlap (constant flow shape).

Different Thicknesses – extrusion distance

Keep constant in cluster for practicality in façade construction and ability to overlap

Reflection

This phase allowed me to properly analyze my physical model from the experimentation phase and identify what the main features of the form are in order to be able to think of a logic for the panel.

This phase was interesting because initially i was trying to replicate the shape of the model as it is without thinking about its components and how i would extract the best elements from it. However i then learned that its a step by step process of extracting parameters and finding parametric methods of working with them.

Working on this panel was also very beneficial to me since it is when i learned many new commands on grasshopper and how to manipulate parameters to obtain different outcomes.

PANEL PROPAGATION

Overlapping the panels in a way which creates 3 Dimensional voids between the panels.

This:

• Allows for the sun’s rays to enter in an interesting way through these gaps.

• Gives chance for some self shading of the panels and the perforations.

• Allow for rotation of the panel which allows for controlling void size – thus controlling light going through.

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Cluster Grasshopper Definition

Cluster Design Variations

Rotating panels so they are all aligned

• Reduced void size between panel in top view

More height difference in panel placement.

• Enlarged void size in 3D due to gap in Z direction.

Remove panel perforations in alternate rows Creates different pattern of light

Incrementing size of centre hole in every row / column Percentage of light going through gradually increases.

Higher level of overlap - Less voids between panels so less light and more self shading.

Rotating alternating rows in a way that minimizes size of voids between panels Controllable feature to control light levels

Changing heights between panels more – façade had protruding / recessed panels.

• The cluster itself flows similar to the way that the panel itself flows, creating unity

• This dynamism may allow for interesting ways that light can enter through the voids in 3D.

30 Double Skin Facade Research

General Definition:

A facade consisting of two layers. Between these two layers there is an intermediate cavity in which air flows through. The two layers are often made of glass. This cavity can generally vary between 0.2 to 2 meters and acts as insulation against extreme temperatures, winds, and sound, thus improving the building's thermal efficiency for both high and low temperatures.

Versatile: Through small modifications, such as opening or closing inlets or outlets or activating air circulators, the behavior of the façade can be changed.

Cold Climate:

Closed cavity - Trapped air heats up from sun and slowly transfers the trapped heat indoorspassive solar heat gain.

Hot Climate: Open cavity - Chimney Effect: differences in air density causes warmer air to rise and escape while denser cool air replaces it. Thus, less heat enters building.

Open Natural Convection:

Air is circulated in the cavity due to buoyancy. This creates  thermal resistance between inside and outside

Closed Natural Convection:

Air is trapped in the cavity and flows due to convection. Heat is transferred inside. Cold Climate.

Forced Convection: Air heated in the cavity is sent to the room space or building entrance with a fan. This system acts as a preheater for the air.

Screening:

Is done using shading devices e.g blinds or louvres; motorized openings, or fans which can be placed in the cavity. These devices protect from solar heat gain and allow diffused light in.

Hot, Arid Climates (Egypt Case):

In hot arid climates, the facade’s configuration is responsible for up to 45%of the cooling loads. The need for air conditioning is needed more in the 9-5 work model of the country, which coincides with the peak temperatures in the day. Natural ventilation is eliminated as an option from March till November.

Dust and high levels of pollution add to the challenge of providing natural ventilation through operable windows during working hours.

Technical Details

Parametric Design Study

Using parametric design, a study developed perforated screens proposed as an outer skin for the aerated/open DSF. The resulting light intensity penetrating the room and is tested for adequacy to the work environment.

The outer skin (perforated screen) is envisioned as a grid of rectangular modules. The different parameters of the modules include the width (w), height (h) and incremental rotation angle (Θ). A total of 540 different cases were simulated to determine the illumination level inside the office space.

• The cavity between the two skins may be either naturally or mechanically ventilated.

• Mechanical fans can be used to solve a humidity problem

• In the context of hot arid climates it is argued that the cavity depth needs to be between 0.6 – 1m) to allow efficient cleaning since dust and pollution levels are high.

• Steel and aluminum supports and frames are used.

Advantages:

• Reduce cooling and heating demand.

• Thermal and acoustic insulation.

• Allow clear views and natural light.

• Allow natural ventilation and air renewalhealthier environment.

Disadvantages:

• High initial cost of construction – higher cost of design and materials.

• Consumes space / takes up ground space

• Needs maintenance

• May fail to function properly if the context /environment changes significantly.

• Cavity may have problems with condensation.

Uses parametric description for the geometry of the façade panels, making the façade responsive to sun exposure and changing incidence angles during the different days of the year.

The screen operates as a curtain wall, sitting 2 meters outside the buildings’ exterior on an independent frame.  Each triangle is coated with fiberglass and programmed to respond to the movement of the sun as a way to reduce solar gain and glare.  In the evening, all the screens will close.

It is estimated that such a screen will reduce solar gain by more than 50%, and reduce the building’s need for energy-draining air conditioning.

Al Bahar Towers, UAE

Hassan, A. G. A. E. (2016). Parametric Design Optimization For Solar Screens: An Approach For Balancing Thermal And Daylight Performance For Office Buildings in Egypt.

Concept:

Responsive Façade that changes the panel orientation and/or protrusion according to angle of incidence.

Sunlight filtration through perforations on the panels.

Rotation: Static Angle of rotation is the same, rotated panels found in certain locations

Protrusions: Responsive Distance of protrusion depends on angle of incidence and what type of room the light is reaching

Grasshopper

Grasshopper Definition Start

Sloped existing building surface: Front view

Initial experimentation of extracted building surface.

Experimentation of overlap, cull index and selecting specific panels to edit.

• Creating segments on the surface using twisted box.

• Number of segments were initially based on the number of glass panels counted on the existing building.

• Placing panels on the segments using box morph.

• Using cull index and list item to try removing and selecting some panelsmethod of creating variation.

Grasshopper Definition

Rotated Panels – decrease size of voids – less direct sunlight.

Un-rotated Panels with Big centre perforation – spaces that need more natural light.

Unpaneled – entrance –voids in the façade makes it look more interesting and keeps entrance location clear.

Un-rotated Panels with small centre perforation – diffuses sunlight due to smaller perforations – Voids between them create interesting pattern when light goes through.

Plan Section

• Show differences in panel type along the section + plan.

• Show the gaps where sunlight goes through.

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Verticalaity of DSF against existing sloped facade gives opportunity for slab extensions in upper floors (section).

Progress includes:

Increasing number of facade segments (doubling) in both U and V directions in order to decrease panel size; they were previously too large (about 2 x 2 m).

Creating logic of panel type distribution / design on the facade based on a studied zoning of spaces.

Un-rotated Panels with Big centre perforation – spaces that need more natural light.

Rotated Panels – decrease size of in between voids – closer to South side – reduce direct harsh sunlight rays

Un-rotated Panels with small centre perforation –diffuses sunlight due to smaller perforations – Voids between them create interesting pattern when light goes through.

Public Coworking Lounge

Offices

Meeting Rooms

Offices Offices

Offices

Public Coworking Lounge

Tech Room

More light, consistent –more formal Varied Light patterns – Less formal Less light

Reception

Reception

Least Light

36 Grasshopper Definition

Preparing the Double Skin Facade Surface:

• Create a new curve offset from the existing facade base.

• Copy that curve straught up until it aligns to top of glass facade.

• Loft the two curevs, resulting in a new vertical surface offset from the glass facade.

• Use twisted box to create segements on the facade where the panels can be placed. Number of segments divisible by number of floors (4 panels per floor)

3 types of panels:

• Unrotated-small perforation

• Unrotated - large perforation

• Rotated - small perforation

For every type of panel, it is given a bounding box to control their placement in the segements and to control how they overlap.

Each panel is placed on the segements using box morph.

Cull index and list item is used to control which type of panel is placed on which segments.

Panel Bounding Box

To make the facade responsive, certain panels will be able to protrude in and out, thus controlling amount of sunlight in.

The direction of movement is perpindicular to the facade: use evaluate surface to get the normal direction. Constructed a domain for the range of distances that the panel will protrude with.

Reflection

This phase was the transition into a more realistic design since the panels were being used to create an actual lifesize facade. This brought up new challeneges such as how the facade panels would fit together realistically and how to adjust them so that their scale was logical.

I enjoyed learning new commands for propagation however this phase was time consuming because the pnaels made the files very heavy. This resulted in me learning techniques to make the design process faster and more efficient.

The important outcome of was coming up with a logic for the building interior and exterior based on the concept.

40 Fabrication Process

Grasshopper Definition

The Fabrication process involved preparing the model to get 3D printed. This meant that certain modifications needed to be added to the model through the grasshopper code.

These modifications were:

• Adding a supporting structure to the panels in order to hold them together since they were overlapping and not touching - this would allow the facade to be printed as one piece since everything would be connected via this sruture.

• Scaling the model down to a size suitable for the 3D printing mechanism.

• Ensuring that all dimensions are not less than 2mm since that is the minimum distance that can be 3D printed.

Fabrication Process

Scale surface down by scale 1:50 (factor 0.02).

Adjust all number sliders with the new scale. Ensure all measurements are above 2 mm after scaling e.g support pipe diameter.

Adjust panel thickness extrusion distance) for the scaled model.

Support Structure:

Extract two points from panel surface by deconstructing it as a mesh. Extend lines from the two points perpindicular to the facade by using evaluate surface to get the normal direction of the facade.

Lines act as the support rod - turned into a pipe with suitable thickness for printing.

Support Structure:

Create verical and horizontal rods along the facade, holding the rods coming out of the panels.

This results in a complete steel support mesh between the panel facade and the building glass facade.

Fabrication Process

Grid structurewhen scaled

up to 1:1

• visible at entrance before removing - shows that the proportion of the panel and supports is realistic since the steel bars should be relatively very thin in 1:1 scale.

• Used this scale to check visullay how many rods should hold one panelchose 2 rods per panel.

1:50 Model doesn’t fit 30x30 cm box for 3D printing. Need to rescale to 1:100

Due to the file crashing, the new scaling is done manually:

• Bake 1:50 facade then scale it by factor 0.5 to make it 1:100

• Therefore, readjusted grasshopper measurements to be at least 4mm (before scaling)

Exporting as STL file to open in Snapmaker software for 3D printing.

Results:

Extremely heavy file; snapmaker crashed in several trials. Several trials included:

• Deleting elements from rhino.

• Changing the maximum distance value in STL export.

Finsihed 1:100 model beside 30x30 cm box

Environmental Analysis

Importing the epw file of Cairo’s weather data. Producing the wind rose and the sun path from the epw file into the rhino file. Control time of year and day - chose noon (12 pm) since the facade faces south west and noon sun shines most on it.

Radiation analysis Environmental Analysis

Radiation Analysis on the glass facade shows a significant reduction in solar radiation due to the double skin facade, increasing thermal comfort. The top of facade and entrance gain a large radiation which needs to be reduced.

Solution: Shading devices above entrance and top slab - reduced solar radiation. Maintained some areas with semi high radiation - assign functions that are not negatively affected by high radiation e.g. storage, warm lounge.

Virtual Reality Building Experience

Connection of support bars to the glass panel and the slabs are unclear. Adjusted connections to glass panel mullions

Virtual Reality Building Experience

Shadow patterns creates a path indicating the outdoor space. No openeing created to the outdoor space.

Added door. Support bars would be adjusted around the door and so that they would not create obstacles in the terrace.

Virtual Reality Building Experience

Lighting patterns displayed (8:00 am).

Interior of office space, shows how it has less light than the lounge space (above), reducing possibilities for glare and discomfort.

Unrotatedsmall perforation

Rotated - small perforation

Unrotated - large perforation

Ground Floor: Reception

In 2D plane, light goes through panel center perforation. Recpetion floor has alternating variety of wide and narrow openings - more interesting / less formal.

First Floor: Offices

Offices have consistant small openings, letting in a more regular and simple light pattern for formal uses.

50 Plans - Lighting and Shadows

Sunlight patterns produced by the panels in every floor.

Floor 0: reception floor with varied shapes on the floor due to having two different panel types as well as unpanelled entrances.

Floor 1: Private offices and meeting rooms: more regular consistant pattern and less light - more formal.

Floor 3: More floor area with light patterns of varied sizes - more informal (coworking public space + lounges)

Floor 5: Clear contrast in lighting where the rotated panels are found; creates a sense of a path to the outdoor terrace.

Project and Course Reflection

The second project was a lot more challenging than the first due to it being on a much larger scale and having a lot more technicalities to adhere to. What made me struggle the most was the speed of rhino and grasshopper; they would continuously crash would made me feel like i was not able to optimize my design sufficiently. However i like the final outcome of the facade, especially after seeing it through the VR experience and seeing the different shadows formed.

Both projects overall taught me a lot about grasshopper and the benefits of parametric design. It was very different from any other course i have taken and a different approch to designing. The best part was being able to see the designs transforming between the different alternatives and developments. Looking back at the initial stage of physical experimentation, i am happy with how i was able to transition a physical idea into a double skin facade design.

Biblography

• Veenendaal, Diederik, et al. “History and Overview of Fabric Formwork: Using Fabrics for Concrete Casting.” Structural Concrete, vol. 12, no. 3, 2011, pp. 164–177., https://doi.org/10.1002/suco.201100014.

• Scherer, Annie Locke. “Concrete Form[Ing]Work: Designing and Simulating Parametrically-Patterned Fabric Formwork for Cast Concrete.” Blucher Design Proceedings, 2019, https://doi.org/10.5151/proceedings-ecaadesigradi2019_193.

• Souza, E. (2019, August 20). How do double-skin façades work? ArchDaily. Retrieved October 23, 2022, from https://www.archdaily.com/922897/how-do-double-skin-facades-work

• Souza, Eduardo. “How Do Double-Skin Façades Work?” ArchDaily, ArchDaily, 20 Aug. 2019, https://www. archdaily.com/922897/how-do-double-skin-facades-work.

• Hassan, Asmaa G, and Asmaa Hassan. “Parametric Design Optimization for Solar Screens: An Approach for Balancing Thermal and Daylight Performance for Office Buildings in Egypt.” Academia.edu, 1 Oct. 2016, https://www.academia.edu/28856880/

• “Fabric Formwork - Fabric Formed Concrete.” Google Sites: Sign-In, https://sites.google.com/site/fabricformedconcrete/introduction/fabric-formwork.

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