EMERY ROTH & SONS’ PROPOSAL DIFFERED

SIGNIFICANTLY FROM THE FIRMS EARLIER

WORK OF “WEDDING CAKE” BUILDINGS,

WHICH WERE VERY PREVALENT IN NEW

YORK BEFORE THE 1961 ZONING RESOLU-

TION WAS ADOPTED. IT BECAME A CUBIC

TOWER SHEATHED IN A SIMPLY MODULATED

GLASS CURTAINWALL. AS EARLY MODELS

SHOW, THE INVOLVEMENT OF GROPIUS AND

BELLUSCHI LED TO A MORE CONSPICUOUS

MODERN GEOMETRIC TOWER FORM. THEIR

DECISION TO ROTATE THE TOWER CREATED

THE COMPLETE SEPARATION THAT NOW EX-

ISTS TO THE NORTH AND SOUTH OF GRAND

CENTRAL AND MADE 200 PARK AVENUE THE

FOCAL POINT IT STILL IS.

EMERY ROTH & SONS PRO-

POSAL FROM FEBRUARY

1955

G R O P I U S / B E L LU S C H I /

ROTH PROJECT

LE CORBUSIER, PROJECT

FOR AN OFFICE BUILDING,

ALGIERS, 1938

GIO PONTI,

PIRELLI HEADQUARTERS,

MILAN, 1958

PIERCING THE TOWER ON EITHER SIDE OF THE NEW YORK CENTRAL BUILDING AND THEN CHISELING BULK AWAY AROUND THE PENETRATIONS CREATES

JUST ENOUGH TRANSPARENCY TO ALLOW THE BUILDING TO REMAIN A FOCAL POINT WITHOUT THE COMPLETE REMOVAL OF MASS BETWEEN THE CORE

AND THE WINGS. REMOVED FLOOR AREA IS RELOCATED TO GRADUATED UPPER FLOORS TO SUGGEST SKYWARD ASCENSION. THE OUTER GLASS SHEATH

RESTORES THE BUILDING TO A SIMPLER GEOMETRY.

ADAPTING THE TAPERED FORM OF THE TOWER AS A GEOMETRIC MODULE/MOTIF CREATES A NON-DIRECTIONAL PATTERN ACROSS THE SURFACE OF

THE TOWER – IN KEEPING WITH EARLY MODELS AND RENDERINGS WHICH EMPHASIZED THE FORM OVER THE SURFACE. APPLIED IN A LARGER SCALE TO

THE TOWER ALLOWS FOR MAXIMUM DAYLIGHTING WHILE THE DENSER, SMALLER SCALE AT THE PODIUM CREATES A MORE MONOLITHIC READING MUCH

CLOSER TO PEDESTRIAN LEVEL.

PANAM UNDER GLASS

+

DESIGN INSPIRATION

NORTH ELEVATIONSOUTH ELEVATION WEST ELEVATION

DOUBLE WALL DETAIL SECTION

TYPICAL UNITIZED CURTAIN WALL

OPERABLE WINDOW

OUTER CURTAIN WALL

DAY LIGHT

THE PERCENTAGE OF NATURAL LIGHT IN REGARDS TO THE OVERALL

LIGHTING IS AN IMPORTANT QUALITY CHARACTERISTIC OF INTERIOR

SPACES. THE ARRANGEMENT OF THE LIGHT-DIRECTING SHADE GUAR-

ANTEES THAT LARGE AREAS OF THE BUILDING ARE SUPPLIED WITH DAY-

LIGHT. THE ILLUMINATION WITH DAYLIGHT REDUCES THE USE OF ARTIFI-

CIAL LIGHT AND THEREFORE ENERGY, REDUCES INTERNAL HEAT LOADS,

AND ENSURES A HIGHER COMFORT OF THE USERS.

NATURAL VENTILATION

THE DOUBLE SKIN FAÇADE ALLOWS FOR OPENING THE WINDOWS OF

THE INNER FAÇADE WITHOUT NOISE OR TURBULENCE ISSUES. DURING

MIDDLE SEASONS, A RELATIVELY HIGH DEGREE OF NATURAL VENTILA-

TION IS PROVIDED, THEREFORE VENTILATION OPERATING COSTS CAN

BE REDUCED. THE BUILDING GETS A HIGH SUPPLY OF FRESH AIR, THE

AIR EXCHANGE TAKES PLACE THROUGH OPERABLE WINDOWS.

GIVING THE USERS CONTROL OVER THE TEMPERATURE AND INDOOR

CLIMATE OF THEIR OFFICE FURTHER INCREASES THE COMFORT LEVEL

AND WELLBEING OF THE OCCUPANTS.

THERMAL PERFORMANCE

THE PROPOSED DOUBLE SKIN FAÇADE IMPROVES THE THERMAL PER-

FORMANCE OF THE BUILDING ENVELOPE THROUGH PASSIVE AND AC-

TIVE MEASURES. THE INNER FAÇADE ALONE REDUCES THE HEAT LOSS

THROUGH THE GLAZING BY APPROXIMATELY 60%. BESIDES THE DOUBLE

GLAZED IGU WITH LOW-E COATING, A HIGH PERFORMANCE UNITIZED

CURTAINWALL SYSTEM REPLACES THE SINGLE GLAZED THERMALLY

UNBROKEN SYSTEM. THE OUTER SKIN ADDS ANOTHER GLAZING LAYER

WITH A STRATEGICALLY PLACED FRITTING TO ENHANCE SOLAR SHAD-

ING IN THE SUMMER AND CREATES A BUFFER ZONE WITH PRECONDI-

TIONED AIR DURING WINTER TIMES.

OVERALL THE U-VALUE CAN BE DECREASED FROM 0.86 BTU/HR-SQ FT °F

TO APPROXIMATELY 0.18 BTU/HR-SQ FT °F.

FACADE OVERVIEW

FRITTING

A MAJOR ASPECT OF ENERGY EFFICIENT DESIGN FOR HIGH RISE OF-

FICE SPACES IS THE REDUCTION OF COOLING LOADS. FRITTED GLASS

ALLOWS FOR A FULLY GLAZED BUILDING ENVELOPE WITH REDUCED G-

VALUE THANKS TO THE LOWER PERCENTAGE OF TRANSPARENT AREA.

THE DIAMOND SHAPED AND DOUBLE CURVED GLAZING PANELS OF THE

PANAM’S UNDER GLASS TOWER WILL BE FRITTED ALONG THE TOP SEC-

TION IN ORDER TO LIMIT THE SOLAR RADIATION AT HIGH SUN ANGLES

DURING THE SUMMER MONTHS. IN WINTER TIME, SUN RAYS AT LOWER

ANGLE ARE ALLOWED INSIDE THE BUILDING HELPING REDUCING THE

REQUIRED HEAT LOADS.

SOLAR SHADING

EXTERNAL SHADING DEVICES ARE UP TO 10 TIMES MORE EFFECTIVE

THAN INTERNAL SHADING. THE DOUBLE SKIN FAÇADE ALLOWS FOR IN-

STALLATION OF SHADING ELEMENTS IN THE CAVITY WHERE WIND SUC-

TION AND TURBULENCES ARE ELIMINATED BY THE EXTERNAL GLASS

PANE. COOLING LOADS CAN BE SIGNIFICANTLY REDUCED IN SUMMER

TIME

SOUND PROTECTION

IN ORDER TO INCREASE WELLBEING AND PRODUCTIVITY OF OCCU-

PANTS, SOUND PROOFING OF THE FACADES IS CRUCIAL. THE DOUBLE

SKIN OF PANAM’S UNDER GLASS TOWER NOT ONLY ENHANCES THE

PERFORMANCE IN REGARDS TO SOUND PROTECTION, BUT ALSO AL-

LOWS OPENING WINDOWS WITHOUT INCURRING IN HIGHER SOUND

LEVELS AT THE INNER OFFICE SPACES.

CLEANING AND MAINTENANCE

FOR CLEANING AND MAINTENANCE ACCESS, 2.5’ WIDE WALKWAYS ARE

INSTALLED EVERY 5TH FLOOR. PERSONNEL CAN WALK ALONG THE FA-

ÇADE IN THOSE AREAS AND LOWER THEMSELVES DOWN IN A BOAT-

SWAIN’S CHAIR TO REACH ADJACENT FLOORS.

STRUCTURAL CONSIDERATION

EXTERNAL SKIN CONSIDERATION

THE EXTERNAL FAÇADE IS A REGULAR PATTERN OF

DIAMOND SHAPES AND RECTANGULAR LAMINATED

GLASS PANELS.

USUALLY ON A CURTAIN WALL FAÇADE, THE MULLION

IS WORKING IN TENSION, THE UPPER PART FIXED AND

THE LOWER PART SLOTTED, ALLOWING SMALL VERTI-

CAL DISPLACEMENT.

IN OUR CASE DUE TO THE OVERLAPPING PATTERN,

WE HAVE TO ALTERNATE AND THEREFORE THE LOAD

DISTRIBUTION CHANGES FROM ONE LEVEL TO THE

OTHER.

TO AVOID POINTS OF DIFFERENT VERTICAL DISPLACE-

MENT BETWEEN THE EXTERNAL SKIN AND THE BUILD-

ING STRUCTURE, WE INSERT A SECONDARY BEAM

FIXED TO THE EXISTING STEEL COLUMNS. THIS CON-

CEPT CAN BE EXTENDED FROM THE REGULAR STO-

RIES TO THE ATRIUM’S

FOR THE DIAMOND PANEL, USING A CONCAVE GLASS SURFACE INCREASES ITS RIGIDITY. THEREFORE ITS THICKNESS CAN BE RE-

DUCED, RELIEVING THE LOAD ON THE STRUCTURE.

FLAT VS CONCAVE PANEL SIMULATION WITH MEPLA A LAMINATED CONCAVE GLASS PANEL 3/5”

DISPLACEMENTS

OUR PROPOSAL DISPLAYS A HIGHLY PERFORMING FAÇADE. THE DOUBLE ENVELOPE OF THE BUILDING ENABLES NATURAL VENTILA-

TION. THE OUTER SKIN IS CONCEIVED AS A RAIN SCREEN AND ACTIVATES THE NATURAL VENTILATION. THE INNER SKIN REGULATES

THE INTERNAL CLIMATE.

TO ACHIEVE OUTSTANDING THERMAL PERFORMANCES, UNITIZED CURTAIN WALL SYSTEM IS CHOSEN FOR THE INNER FAÇADE. UNIT-

IZED CURTAINWALL ARE ENGINEERED TO BE FULLY ASSEMBLED AND GLAZED IN A FACTORY ENVIRONMENT. NOT ONLY IT INCREASES

THE SPEED OF FIELD ERECTION, BUT IT ALSO PROVIDES DRAMATIC IMPROVEMENTS OF QUALITY FINISHES AND GLOBAL PERFOR-

MANCES.

TWO MODULUS ARE DESIGNED, ONE INCLUDING OPERABLE WINDOW TO ALLOW AN INDIVIDUAL CONTROL OF THE CLIMATE ENVI-

RONMENT. THE CURTAIN WALL ELEMENTS HAVE BEEN DETAILED TO ACHIEVE EXCEPTIONAL THERMAL, AIR AND WATER INFILTRATION

PERFORMANCE. THE MODULES ARE TOP SUPPORTED AT SLAB LEVEL AND LATERALLY RESTRAINED AT THE BASE.

DETAIL SECTION

STRESSES

INSTALLATION SEQUENCE

EXISITING STRUCTURE

THE STRUCTURE IS COMPOSED OF STEEL COLUMNS COVERED

WITH PLASTER AND STEEL BEAMS SUPPORTING THE PRECAST

CONCRETE SLABS. THE EXISTING STRUCTURE IS ASSUMED TO

BE SOUND AND IS KEPT FOR THE PROJECT.

SECONDARY STRUCTURE

THE ARCHITECTURAL PROJECT INTRODUCES AN ADDITIONAL

EXTERNAL SKIN, THEREFORE INCREASES THE FAÇADE LOADS.

THE EXTERNAL SKIN WILL BE FIXED TO A NEW SMALLER STEEL

BEAM, INDEPENDENT FROM THE EXISTING STRUCTURE IN OR-

DER TO ALLOW UNCONNECTED DISPLACEMENT.

UNITIZED GLAZING SYSTEM

THE INTERNAL SKIN IS A UNITIZED CURTAIN WALL MADE OF

DOUBLE INSULATED GLAZING UNITS. THE PREFABRICATED

MODULES ARE HUNG ALONG THE CONCRETE SLABS TO FORM

THE BUILDING THERMAL ENCLOSURE. UNITIZED CURTAIN WALL

ALLOW QUICK AND CHEAP INSTALLATION PROCESS AND AN

INTERIOR CLIMATE CONTROLLED ENVIRONMENT.

EXTERNAL SKIN

THE EXTERNAL CURTAIN WALL FRAME IS MADE OF STEEL HOL-

LOW SECTION ON WHICH STEEL PLATES ARE WELDED PUNC-

TUALLY . THESE ARE FIXED TO THE INNER SECONDARY STEEL

STRUCTURE VIA THE STEEL CANTILEVERED ELEMENTS. THE DI-

AMOND SINGLE GLAZING PANELS WITH A DOUBLE CURVATURE

ARE NON-OPERABLE. THE RECTANGLE GLAZING PANELS CAN

BE OPENED FOR NATURAL VENTILATION

LEGEND

STRUCTURE 1. EXISTING STEEL PILASTER

2. EXISTING W BEAM

3. CONCRETE SLABS

4. NEW SECONDARY BEAM:

DOUBLE C PROFILE

WELDED STEEL PLATES

INTERNAL SKIN: UNITIZED SYSTEM

5. DOUBLE GLAZING UNIT

6. ALUMINUM FRAME

7. STEEL REINFORCEMENT

8. MULLION’S FIXATION BRACKET

9. INSULATED PANELS

10.OPERABLE WINDOW

EXTERNAL SKIN

11. DOUBLE CURVED SINGLE GLAZING UNIT

12. STEEL FRAME

13. WELDED STEEL PLATE

14. CANTILEVERED STEEL ELEMENT

15. FIXATION BRACKETS

THERMAL PERFORMANCE

VENTILATION SCHEME

ONE MAJOR ADVANTAGE OF THE DOUBLE SKIN FAÇADE IS THE OPPORTUNITY

FOR NATURAL VENTILATION DURING SPRING AND FALL SEASON WHEN THE

OUTSIDE TEMPERATURES IN NYC ARE MODERATE. THE OPERABLE WINDOWS

IN THE CURTAIN WALL ALLOW THE OCCUPANTS TO HAVE ACCESS TO FRESH

AIR WITHOUT ANY NOISE OR TURBULENCE ISSUES.

A BUILDING AUTOMATION SYSTEM WILL OPERATE OPENING THE OUTER SKIN

TO GUARANTEE IDEAL TEMPERATURES IN THE CAVITY. DURING THE SUMMER

SEASON AUTOMATICALLY OPENING THE INTERIOR WINDOWS FOR NIGHT-TIME

COOLING WILL REDUCE THE COOLING LOADS OF THE BUILDING’S HVAC SYS-

TEM.

IN ORDER TO CONTROL THE STACK EFFECT AND FOR A BETTER SOUND PRO-

TECTION, THE FAÇADE WILL BE DIVIDED INTO SEVERAL SEGMENTS OF AP-

PROXIMATELY FIVE FLOORS. EACH SEGMENT WILL HAVE OPERABLE UNITS

AT THE BASE TO LET IN COOL AIR AND THE TOP TO VENT OVERHEATED AIR.

THE DIAMOND PATTERN ALLOWS FOR ALTERNATING THE OPENINGS TO AVOID

CROSSING OF EXHAUST AND FRESH AIR.

WHERE THE DOUBLE SKIN CAVITY IS TRANSFORMED INTO ATRIA, MULTI-STO-

RY VOIDS ARE CREATED AT DIFFERENT LEVELS OF THE TOWER. THESE ATRIA

BRING ADDITIONAL DAYLIGHT AND FRESH AIR INTO THE BUILDING.

THEY CREATE AREAS WHERE OCCUPANTS CAN ENJOY INTERESTING OUT-

LOOKS, BRINGING A RICHNESS TO THE WORKSPACE. FURTHERMORE THE

ATRIA GIVE THE BUILDING A SENSE OF TRANSPARENCY AND LIGHTNESS FROM

THE OUTSIDE.

WINTER

IN WINTER TIMES THE FAÇADE CAVITY CAN BE

USED AS A BUFFER ZONE. PRE-CONDITIONED AIR

THAT HAS BEEN HEATED UP BY THE SUN ALLOWS

FOR INDIVIDUALLY CONTROLLED NATURAL VENTI-

LATION WITH WARM FRESH AIR. THE HIGHER TEM-

PERATURE OF THE GLAZED CURTAIN WALL SUR-

FACE CREATES A HIGHER AMBIENT TEMPERATURE

AND THEREFORE INCREASE THE COMFORT LEVEL

FOR THE OCCUPANTS. THE LOW SUN ANGLE AL-

LOWS FOR NATURAL LIGHT TO REACH DEEPER

INTO THE BUILDING, HELPING TO REDUCE LIGHT-

ING LOADS.

SUMMER

THE MAIN FUNCTION OF THE DOUBLE SKIN IN

SUMMER IS TO REDUCE COOLING LOADS FOR THE

BUILDING. THE SPACE BETWEEN THE TWO SKINS

WILL BE VENTILATED, THROUGH THE STACK EF-

FECT WARM AIR WILL VENT OUT AT THE TOP AND

COOLER AIR CAN BE DRAWING INTO THE CAVITY

FROM THE BOTTOM. OPENING THE WINDOWS FOR

NIGHT COOLING CAN BE AN EFFICIENT WAY TO RE-

DUCE COOLING LOADS. MORE IMPORTANT IS THE

USE OF EXTERNAL SHADING SYSTEMS WHICH ARE

LOCATED IN THE CAVITY. THE SOLAR RADIATION

REACHING THE INSIDE OF THE BUILDING CAN BE

REDUCED BY UP TO 90%

ENERGY CONSIDERATIONS

IN NYC EXISTING LARGE OFFICE BUILDINGS CONSTRUCTED BEFORE 1980 HAVE THE FOLLOWING BUILDING ENERGY USE BENCH-

MARKS:

COOLING: 15.5 KBTU/SFT (49 KWH/SQM)

HEATING: 14.4 KBTU/SFT (45 KWH/SQM)

INTERIOR LIGHTING 16.07 KBTU/SFT (51 KWH/SQM)

WATER HEATING: 0.4 KBTU/SFT (1.3 KWH/SQM)

VENTILATION: 3.1 KBTU/SFT (10 KWH/SQM)

INTERIOR EQUIPMENT 15.94 KBTU/SFT (50 KWH/SQM)

IT CAN BE ASSUMED THAT THE CURRENT METLIFE BUILDING HAS SIMILAR VALUES IN REGARDS TO ENERGY CONSUMPTION. MAIN DRIV-

ERS FOR THE DEMAND OF ENERGY ARE COOLING, HEATING AND INTERIOR LIGHTING. THE FOLLOWING PARAGRAPH EXPLAINS THE

ENERGY SAVING STRATEGIES OF PANAM’S UNDER GLASS TOWER.

COOLING LOADS

THE HIGH COOLING LOADS IN EXISTING OFFICE BUILDINGS CAN BE DIVIDED INTO INTERNAL LOADS AND EXTERNAL LOADS. SOLAR

GAINS THROUGH THE FACE MAKE FOR 30% OF THE COOLING DEMAND (4.65 KBTU/SFT), INTERNAL LIGHTS CONTRIBUTE 36% (5.58

KBTU/SFT).

THE PROPOSED DOUBLE SKIN FAÇADE ALLOWS FOR AN INSTALLATION OF EXTERNAL SHADING ELEMENTS. THE TRANSMITTED SOLAR

ENERGY CAN BE REDUCED BY MORE THAN 90%. FURTHERMORE THE DAYLIGHT DIRECTING SYSTEM WILL REDUCE THE INTERNAL

COOLING LOADS FOR ARTIFICIAL LIGHTING BY APPROXIMATELY 20%.

EXAMPLE: SOLAR ENERGY = 1000 W/M²

REDUCTION VALUE: FC = 0,05 / 0,57 = 0,08

INTERIOR LIGHTING

WITH THE FULL HEIGHT GLAZING THE AMOUNT OF NATURAL DAYLIGHT FOR THE OFFICE SPACES CAN BE INCREASED. IN ADDITION THE

DAYLIGHT DIRECTING SYSTEM WILL DIRECT LIGHT DEEPER INTO THE BUILDING AND THE DEMAND FOR ARTIFICIAL LIGHTING CAN BE

REDUCED BY APPROXIMATELY 20%, ENERGY SAVINGS OF UP TO 3.2 KBTU/SFT CAN BE EXPECTED.

HEATING LOADS

VENTILATION

A DOUBLE SKIN FAÇADE ALLOWS FOR NATURAL VENTILATION DURING THE SPRING AND FALL SEASONS. IN THE WINTER PRE-

CONDITIONED AIR FROM THE CAVITY CAN BE USED FOR VENTILATION AND CONTRIBUTE TO ENERGY SAVINGS.

ENERGY SAVINGS

GLAZING WITHOUT SHADING

G-VALUE (GLAZING) = 0,57

TRANSMITTING SOLAR ENERGY = 570 W/M²

GLAZING + EXTERNAL SHADING

G-TOTAL-VALUE = 0,05

TRANSMITTING SOLAR ENERGY = 50 W/M²

HEATING LOADS ARE PREDOMINATELY

CAUSED BY HEAT LOSSES THROUGH THE FA-

ÇADE. FOR THE METLIFE BUILDING 8.6 KBTU/

SFT ENERGY CONSUMPTION CAN BE ASSO-

CIATED WITH THE SINGLE GLAZED BUILDING

ENVELOPE. IMPROVING THE GLAZING AND

INTRODUCING AN AIR TIGHT CURTAINWALL

IN COMBINATION WITH A SECOND EXTERNAL

SKIN WILL REDUCE THE HEAT LOSS BY AP-

PROXIMATELY 60%.

THROUGH ALL MEASURES DESCRIBED IN THE

PREVIOUS PARAGRAPHS, ENERGY SAVINGS

OF 25% OR MORE CAN BE ACHIEVED. INTE-

RIOR EQUIPMENT AND LIGHTING HAVE HIGH

POTENTIAL FOR IMPROVEMENT IN ORDER TO

ENHANCE THE OVERALL PERFORMANCE OF

THE BUILDING.