Julianatorens: Facade design

JULIANATORENS A multifunctional tower in The Hague

Facade Design Maria Mourtzouchou Tutor: Roel Schipper MEGA 2017

AR0026 MEGA 3/6/2017

MSc Architecture, Urbanism and Building Sciences track Building Technology TU Delft Faculty of Architecture and the Built Environment

TABLE OF CONTENTS 1. Building Concept

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4 6

2. Facade Concepts

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8

3. Climate Integration

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10

4. Construction System

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12

5. Court Facade

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16

6. South Facade

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24

7. Offices North Facade

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32

8. Hotel & Dwellings North Facade

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34

9. Hotel West Facade

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38

10. Facade Construction

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page

11. Maintenance

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page

1.1 Design decisions of the different program uses 2.1 Requirements of the different program uses

4.1 Detailing 4.2 Installation

5.1 Concept evolution 5.2 Isometric View 5.3 Materialization - UHPC 5.4 Detailing 6.1 Isometric View Dwellings 6.2 Isometric View Offices & Hotel 6.3 PV Panels Performance 6.4 Detailing 7.1 Isometric View 7.2 Materialization - Translucent effect 7.3 Detailing 8.1 Isometric View 8.2 Materialization - Metal Insulated Panels 8.3 Detailing 9.1 Isometric View 9.2 Detailing - External Sunshading System 9.3 Detailing

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page page page page page page page page page page page page page page page page page page page

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13 14 17 19 20 21 25 26 27 28 32 33 33 35 36 37 39 40 41

design evolution

1. Building Concept “Julianantorens� is a high-rise, mixed-use building located next to The Hague Central station. It incorporates the uses of the International Criminal Court (ICC), a hotel, offices, dwellings as well as general uses. The architectural concept of the building wanted the people to experience it from two different scopes; from afar and from nearby. The Court being at the base follows the city grid, whereas the two towers are oriented to the south to maximise energy efficiency. The basic idea was to seperate the Court from the rest of the functions, an idea which is very much enhanced by the facade. The impression of the two towers seems the same whereas the court stands out to be different.

Slab

Two towers

From afar

From nearby

Orientation

Bridges

Separations Final shape

figure 1: stacking of uses

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FACADE DESIGN REPORT | building concept

Typical Hotel & Offices floor plan

Ground floor plan - General uses

Transverse Section

Typical Dwellings floor plan

Typical Court floor plan

East Impression

North Impression

South Impression

West Impression

Longitudinal Section

FACADE DESIGN REPORT | building concept

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1.1 design decisions of the different program uses

Court A “box in a box� concept is used in order to isolate the ICC from the outside environment. This is achieved with an exterior, open Brise Soleil facade with lighweight UHPC panels, which let natural sunlight in and then diffuse it upwards and a second all-glass facade inside. Thus, a corridor is formed perimetrically between these two facades, which creates not only nice routes leading to the courtrooms, but also giving interesting views to the outside.

Hotel The position of the hotel on the site was chosen in a way that it offers a nice view to the city center. The west facade has an external vertical sunshading system to minimise overheating which resembles the rhythm of the court and goes up until the dwellings. On top of the hotel, the facilities provided are a restaurant, a gym and a swimming pool.

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FACADE DESIGN REPORT | BUILDING CONCEPT

Offices The position of the offices on the site gives the best orientation to maximise the benefits of daylight. At the north and east side, a translucent facade achieved with aerogel glazing provides diffuse light and privacy at the same time. At the south a double-skin facade with PV panels is used to improve the indoor environment.

Dwellings The dwellings are placed on top of the two towers providing the best view to the city. At the south side the double-skin of the hotel and offices is continued but it is converted in a buffer zone creating also a balcony for the residents. At the north and east side, metal insulated panels and glazing are alternating.

FACADE DESIGN REPORT | BUILDING CONCEPT

2. Facade Concepts

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FACADE DESIGN REPORT | facade concepts

2.1 Requirements of the different program uses The facade concepts presented on the left page were evolved according to the requirements presented Table 1 which were set in cooperation with the Climate Designer and the Architect. These requirements are based on the needs of the users, on climate parameters with the aim of maximising energy efficiency and on aesthetics. Thus, more than one facade design is needed as a result of the mixed use program with ranging functional requirements and different orientations.

Nevertheless, the bulding should be seen also as a whole and have a consistent appearance. The aesthetic value prevalent in the whole building is verticality. Despite the fact that different facade concepts are created the rhythm is kept the same by alternating two units of glazing with one unit of the relative facade material.

In particular, the facade units have always floor-to-ceiling height but there are two different spacings from mullion to mullion. For the court and the west facade with the shading system a spacing of 0.90m is used in order to achieve maximum performance. For the rest of the building there is a spacing of 1.25m.

Court

Offices

Hotel

Dwellings

closed space

open, flexible

closed (rooms), open (common spaces)

closed

8:00 - 19:00 5/7 days

7:00 - 18:00 5/7 days

0:00 - 10:00 ; 16:00 - 00:00 7/7 days

00:00 - 8:00 ; 15:00 - 00:00 7/7 days

central

N/E/S

N/W/S

N/E/S/W

21-23 °C

18-23 °C

18-23 °C

18-23 °C

23-26 °C

23-26 °C

23-26 °C

23-26 °C

1 dm3/s per m2

1 dm3/s per m2 operable windows

0,7 dm3/s per m2 operable windows

0,7 dm3/s per m2 operable windows

natural from the back of the judjes; indirect; diffuse

indirect; diffuse; 500 lux

natural; not too relevant

daylight, depending on the rooms

no

yes

yes

yes

no

green/other buildings

not relevant

green/skyline

high insulation

changeable according to the needs

high between the rooms

high between the dwellings

Table 1: requirements of the different program uses

FACADE DESIGN REPORT | facade concepts

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3. climate integration Ventilation, heating and cooling are combined in the same HVAC system. Every function is regulated by a mechanical air supply that ventilates and, according to the necessity, heats or cools the environment. The mechanical supply is sized to provide sufficient fresh air into the indoor environment, but, except for the court block, every space has operable windows that allow the users to directly adjust their environment. The total routing of the ventilation is showed in the Figures 2 and 3 for summer and winter respectively, where the supply and exhaust flows are differentiated to show how the air goes inside and exits the building. The climate of the south facade with the double-skin in the hotel and offices and the buffer zone in the dwellings is illustrated more detailed in Figures 4,5,6 and 7.

operable windows

operable windows

Heat tecovery system between supply and exhaust air Double-skin facade, multi-storey shaft

Double-skin facade, air pre-heating

figure 2:HVAC summer

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FACADE DESIGN REPORT | climate integration

figure 3:HVAC winter

figure 4: summer situation - double skin facade - offices

figure 6: summer situation - buffer zone- dwellings

figure 5: winter situation - double skin facade - offices

figure 7: winter situation - buffer zone - dwellings

FACADE DESIGN REPORT | climate integration

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4. Construction System A unitised system was chosen for the facade construction of the “Julianatorens” because it is the most efficient for a high-rise building. It gives endless possibilities in design freedom whilst keeping a high quality finished product due to pre-fabrication.

The system used in particular is Schueco Facade USC 65 (Unitised System Construction). This system offers an allround narrow face width of only 65mm as well as large unit dimensions with maximum unit weights up to 500kg. In addition, different design variants for frame appearance are provided giving the opportunity of semi-structural glazing.

Another benefit is that with the facade bracket made from glass fibre-reinforced plastic, loads such as solar shading systems can be connected safely and without thermal bridges.

Technical information Thermal insulation Airborne sound insulation Burglar resistance

Values Uf = 1.4 - 2.0 W/(m2K) Rw = 46 dB Class WK2

Air permeability

Class AE

Watertightness

Class RE 1200

Wind load resistance Impact resistance

± 2,25 KN/m2 Class I5 / E5

The system is out of Aluminium and is highly thermally insulated providing a Uf value of 1.4 - 2.0 W/(m2K).

Moreover, all opening types of windows can be implemented from inward-opening turn/tilt vents to outward-opening projected top-hung or parallel-opening vents. The glass thicknesses can vary between 4 mm and 16 mm for single glazing and between 16 mm and 56 mm for double insulating glass whereas the possibility for triple glazing is also provided.

figure 8: schueco facade usc 65

figure 9: impression of all-glass profiles

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FACADE DESIGN REPORT | construction system

figure 10: window frame attachment

4.1 detailing The following details are the profiles used to construct the facade of the building. The standard mullion and transom profiles (Detail 01 & 02) are used to form the unit whereas inbetween a different profile is used (Detail 03) when needed, for example in the case of attaching a window frame.

Moreover, the all-glass transom profile (Detail 04) is used in the cases where the horizontal caps should not be visible in order to enhance the verticality. The all-glass solution is also used for the corners of the two towers (Detail 05).

detail 01: standard mullion profile scale 1:5

detail 02: standard transom profile scale 1:5

detail 03: standard transom profile between unit scale 1:5

detail 04: All-glass transom profile for vertical emphasis scale 1:5

detail 05: all-gLASS cORNER SOLUTION scale 1:5

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4.2 iNSTALLATION The unitised facades are composed out of individual prefabricated elements (Figure 12). This results in a fast and economic installation with limited use of resources in manpower and tooling compared to traditional curtain walls.

In addition, this construction principle (Figure 11 and 13) is extremely suitable for high-rise constructions, allowing the necessary tolerances with regard to the building movement, and giving the opportunity to finish the building construction floor by floor allowing for parallel construction inside the building.

figure 11: standard element installation

figure 12: overview of the element or unitised facade system

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FACADE DESIGN REPORT | construction system

figure 13: Detail of standard bracket functionalities

detail 06: section of unit attachment to a typical floor scale 1:5

detail 07: plan (A-a) of unit attachment to a typical floor scale 1:5

FACADE DESIGN REPORT | construction system

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5. CoURT FACADE

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FACADE DESIGN REPORT | court facade

5.1 concept evolution The court, being one of the most important elements of the achitectural concept needed a facade that would make it seem an important public building that everyone would recognise.

With the “box in a box� concept, the first design idea evolved was to attach metal panels that would not only create interesting light patterns to the inside but also function as shading (Figures 14 and 17). However, this idea was soon rejected because the pattern created shown in figure n did not let much light in so other solutions like changing the pattern had to be considered.

It may be that the Court does not need direct light but there are also offices required for the Court which need light, a view and contact with the outside environment. These parameters imposed that further design experimentations needed to be done. figure 15: reference project Gateway Plaza Richmond, VA, USA Forum Studio & Longo-Park Architects high-performance glass curtain wall system aluminium panels hung on aluminium extruded tubs with clips and hangers

figure 16: reference project Casuariestraat, The Hague, NL Fokkema & Partners Archittecten second-skin | varied reflections

figure 14: impression of the first facade court design idea

FACADE DESIGN REPORT | court facade

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The first alternatives were to change the existing panels by cutting parts of it to let more light reach the interior (Figures 18 and 19). However, the light being able to penetrate the facade was still not sufficient. Another solution was to use glass panels with transparent and fritted parts (Figure 20) instead of metal ones. However, the concept of the “box in a box� would be almost lost so another solution needed to be considered to match the architectural concept.

figure 17: attachment proposal of the steel panels - first design idea

figure 18: pattern shape exploration

figure 19: first pattern alternative

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FACADE DESIGN REPORT | court facade

figure 20: second pattern alternative

5.2 Isometric view

A freeform parametrically designed shading system composed of ultra high performance concrete panels is designed for the Court facade which met all the parameters. This Brise Soleil facade lets the natural sunlight in and then diffuses it upwards instead of directly onto the building. In addition, the fiber-reinforced UHPC allows the production of thin, lightweight panels with large surface areas, an aspect which iss much preferred since the facade is non-loadbearing supported by the main structure of the building. The spacing of the panels is 0.90m

figure 21: isometric view of court facade

FACADE DESIGN REPORT | court facade

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5.3 materialization - uhpc The material chosen to fabricate the panels for the court facade is ultra-high-performance concrete (UHPC) by DuctalÂŽ. This material combines an ultra-high performance mineral matrix with either organic, metallic, stainless steel or glass reinforcing fibers.

This material was chosen because of the following advantages: 1. It is specifically-designed and developed for architectural applications.

2. It provides architects and designers with the freedom to create custom-made complex shapes, surfaces and textures for a wide range of applications.

3. It offers exceptional strength, ductility and durability.

Many pieces are significantly thinner and require little or no traditional reinforcement.

4. Its unique structure improves environmental performance and overall resistance to contribute positively to life-cycle analysis costs.

5. With its extremely low permeability, water and abrasive elements are unable to penetrate the concrete matrix.

The most important aspect though for choosing UHPC is that thin sections and long spans can be created thus making the panels lighter and innovative in geometry and form. This way the overall facade is substantially more lightweight which was an important aspect for the project since the panels would be supported by the main structure.

As far as the production method is concerned, the court panels are constructed with precast elements. These are manufactured with custom foam moulds which are needed to produce the freeform parametrically designed panels.

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FACADE DESIGN REPORT | court facade

4 to 8 times higher compressive strength than conventional concretes

Compression behaviour is almost linear elastic up to the maximum stress and exhibits no damage to the material during this phase

figure 22: Stress curve - deformation for a sample of DuctalÂŽ with metallic fibers

The fibers give the material a ductile behaviour during bending The ductility behaviour observed during bending is characterised by multiple cracks before the stress peaks, without localization and without the presence of any major cracks

figure 23: bending behaviour

5.4 detailing

d10

d09

detail 08: court typical floor section scale 1:20

FACADE DESIGN REPORT | court facade

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detail 09: detail of court typical floor section scale 1:5

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FACADE DESIGN REPORT | court facade

detail 10: detail of court typical floor section scale 1:5

FACADE DESIGN REPORT | court facade

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6. south FACADE

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FACADE DESIGN REPORT | south facade

6.1 Isometric view dwellings

A buffer zone is created at the south side of the dwellings as a continuation of the double-skin facade at the lower levels of the offices. Two units of glazing and one unit of PV panels are altenating keeping the rhythm of 1.25m from mullion to mullion.

figure 24: isometric view of dwellings south facade

FACADE DESIGN REPORT | south facade

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6.2 Isometric view offices & hotel

At the south side of the offices a doubleskin facade is constructed. Again two units of glazing and one unit of PV panels are altenating keeping the rhythm of 1.25m from mullion to mullion. figure 25: isometric view of offices south facade

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FACADE DESIGN REPORT | south facade

6.3 PV Panels performance Within the sustainability concept of the high-rise building, PV panels are placed in the south facade as well as on the roofs of the two towers in order to try and approach a nearly zero-energy design. In Table 2 the total energy produced is calculated which represents the 32% of the heating and cooling demand.

PV Panels PV Panels integrated integrated in the in the double skin facade double skin facade androof on the roof and on the

E = A * r * H * PR E = Energy (kWh) A = Total solar panel Area (tm²) r = solar panel yield (%) H = Annual average irradiation on tilted panels PR = Performance ratio, coefficient for losses

Mechanical Mechanical Room Room Heat Recovery Heat Recovery System System

Orientation

A (m2)

r

H (kWh/m2)

PR

E (kWh)

0o South

2.208,8

0,2

1.098,7

0,9

436.795,8

0o South - East

1.038,5

0,2

886,6

0,9

165.729,3

36o South

2.753,0

0,2

1.266,6

0,9

627.626,187

Total

1.230.151,3

table 2: calculation of the energy produced by the pv panels

Geothermal Heat Geothermal Heat Pump System Pump System FACADE DESIGN REPORT | south facade

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6.4 detailing

d12

detail 11: dwellings typical floor section scale 1:20

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FACADE DESIGN REPORT | south facade

detail 12: detail of dwellings typical floor section scale 1:5

FACADE DESIGN REPORT | south facade

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d14

detail 13: double-skin offices typical floor section scale 1:20

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FACADE DESIGN REPORT | south facade

detail 14: detail of double-skin offices typical floor section scale 1:5

FACADE DESIGN REPORT | south facade

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7. offices north FACADE 7.1 Isometric view

For the north facade of the offices, aerogel is used in order to achieve the translucent effect. Two units of triple glazing and one unit of double glazing filled with aerogel are alternating keeping again the rhythm of 1.25m from mullion to mullion. With this concept more light is able to enter the open plan offices ensuring privacy at the same type with the semi-transparent areas.

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FACADE DESIGN REPORT | offices north facade

figure 26: isometric view of offices north facade

7.2 materialization - translucent effect Aerogel is a material that is 98.2% air and it is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas.

The result is a solid with extremely low density and low thermal conductivity.

aerogel properties

7.3 detailing

detail 15: north offices typical floor section scale 1:20

FACADE DESIGN REPORT | offices north facade

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8. hotel & dwellings north FACADE

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FACADE DESIGN REPORT | hotel & dwellings north facade

8.1 Isometric view

At the north side of the hotel and dwellings metal insulated panels are used for the wall construction to ensure the privacy required by these uses.

Two units of glazing and one unit of sandwich panels are altenating keeping again the rhythm of 1.25m from mullion to mullion.

figure 27: isometric view of hotel & dwellings north facade

FACADE DESIGN REPORT | hotel & dwellings north facade

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8.2 materialization - metal insulated panels The material chosen for the walls of the hotel and dwellings is Kingspan’s Optimo™ Smooth insulated metal panel. It is a single component insulated metal panel product, thus producing faster on-site installation compared to multipart foam insulated panels, while minimizing construction delays and potentially saving on labor costs. Moreover, the metal insulated with foam panels provide air tightness, low thermal bridging, and thermal performance of high R-value.

The exterior face is 22 Ga. Smooth Galvalume® wheras the core material consists of Polyisocyanurate (PIR) and it provides a double tongue and groove interlocking rainscreen joint. The U-value is 0.15 W/m2K at 24oC. This material was chosen because of the following advantages: 1. The core consists of continuous, rigid insulation offering superior airtightness performance.

2. The exterior skins contain a substantial amount of recycled content, and the panels themselves are recyclable.

3. It is simple to attach, reducing installation errors.

detail 16: panel joint detail scale 1:5

detail 17: Optimo™ Smooth insulated metal panel detail scale 1:5

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FACADE DESIGN REPORT | hotel & dwellings north facade

8.3 detailing

detail 18: north Hotel & dwellings typical floor section scale 1:20

FACADE DESIGN REPORT | hotel & dwellings north facade

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9. hotel west FACADE

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FACADE DESIGN REPORT | hotel west facade

9.1 Isometric view

At the west side of the hotel and dwellings metal insulated panels are used again like at the north facade with the difference that an external sun shading system is also used to avoid overheating of the interior. Two units of glazing and one unit of sandwich panels are altenating, however, in this situation the rhythm of the court facade is continued with mullion to mullion spacing of 0.90m.

figure 28: isometric view of hotel west facade

FACADE DESIGN REPORT | hotel west facade

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9.2 detailing - external sunshading system The Brise Soleil System chosen for the west facade of the hotel and dwellings resembles the one of the court keeping the same rhythm. This rhythm, namely a spacing of 900mm was defined in collabortion with the Facade designer after considering the azimuth angle at the building location.

Moreover, the blade size was calculated to be 300mm according to this spacing. In addition, the product chosen, namely the VersoleilTM SunShade single blade system offers the possibility of -35o to 35o blade angle which makes the shading even more efficient and easily changeable.

This specific sun shading system was chosen because of the following advantages: 1. Standardized solution for seamless integration 2. Highly versatile design allows for variable blades options 3. Innovative mounting design allows for multiple angles maximising shading performance 4. Tested for combined wind, snow and dead loads 5. Thermally broken attachment method 6. Screw spline construction 7. Potential Leadership in Energy and Environmental Design (LEED) credits

detail 19: plan of blade connection to the unitised mullion profile scale 1:5

detail 20: section of splice joint connection of blade to the unitised transom profile scale 1:5

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FACADE DESIGN REPORT | hotel west facade

9.3 detailing

detail 21: west Hotel typical floor section scale 1:20

FACADE DESIGN REPORT | hotel west facade

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10. FACADE construction

11. maintenance

The facade construction system is unitised as already mentioned which means that on-site assembly hours, resources in manpower and tooling are minimised. Another advantage is that the building construction can be done floor by floor allowing for parallel construction inside the building. This means that as soon as the main structure of the corresponding facade is ready, the facade construction can start. Individual pre-fabricated elements are put and fixed with a bracket allowing the necessary tolerances with regard to the building movement. This results in a fast and economic installation.

The building maintenance is a very important aspect for the building in order to achieve a long lasting quality for the facade. It prevents degradation and corrosion of the surface materials and maintains aesthetics. For this reason, the facade should be cleanded minimum twice a year. Besides the cleaning, access to the facade is also important for maintenance purposes.

Internally, access can be realised from the floors, from the double skin facade maintenance walkway, from access doors, etc. Externally, the two towers can be accessed and cleaned by a singular crane system. BMUs (Building maintenance units) can be placed on top of the two towers roofs perimetrically on a track system to provide maximun coverage. The crane type unit (Figure 29) has a cantilevering and adjustable arm so that all sides of the towers can be reached easily. BMUs have high capital costs and are exposed, nevertheless they are safe, easy to use and have low operational costs. For the court because of the ununiform shape of the panels it is not possible to have crane acccess. For this reason, a maintenance crane (Figure 30) will be needed which may cause a minor incovenience in the circulation of the ground level access, however, it is the easiest and the most cost efficient solution.

The facades of “Julianatorens� are non-loadbearing so they should be attached to the main structure which means that as soon as the metal and concrete works have finished the facade construction can start. Being a high-rise constructed of large scale elements, a tower crane will be necessary so that the different panels can be hoisted easily.

For the court as soon as the main structure is ready the units of the inner leaf can be attached to their set location.

There is a rigid frame supporting the exterior facade which carries both vertical and horizontal loads. For the double skin facade, first the inner leaf is constructed and at the same time the outer leaf can be erected. and then the external one with the PV panels. The same principle applies also for the single skin facades. The units are every time attached on the main structure, which consists of a ribbed composite floor supported by steel HE sections and HEM 400 beams every 4 meters. An additional UPN profile is used to connect those beams in the cases of the two-layered facades (court, dwellings, double-skin) in order to withstand deformation because of the facade weight.

figure 29: track system at roof level

figure 30: maintenance crane

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FACADE DESIGN REPORT | construction & maintenance

“julianatorens� physical model

court facade fragment physical model