Dubai Building Code (2021)

Dubai Building Code

Part D: Vertical transportation

D 38

D.9.8.2

Acceleration and jerk

Lower acceleration and jerk values provide better

perceived comfort for passengers. Table D.39 gives

recommended maximum values.

For bed elevators, acceleration shall not exceed

0.6 m/s

and jerk shall not exceed 1.0 m/s

Speed (m/s)

Acceleration (m/s

) Jerk (m/s

)

0.7

0.8

1.5 to 1.75

0.8

0.9

2.0 to 2.5

0.9

3.0 to 4.0

1.1

≥5

1.2

1.4

Table D.39 Recommended maximum acceleration and jerk at a given

speed

D.9.8.3

Destination control systems

Conventional elevator control systems are the most user-friendly, but they can be less efficient compared to

destination dispatch (DD)/hall call destination control (HCDC), or a destination control system (DCS).
Figure D.25 illustrates a conventional control system and Figure D.26 illustrates a DCS. In a DCS, the passenger

enters the destination floor before entering the cabin. The terminal shows floor numbers or a telephone keypad.

Key

01: Typical floors

02: Boarding floors

Figure D.25

Conventional control system

Figure D.26

Destination control system

Dubai Building Code

Part D: Vertical transportation

D 39

A DCS is preferred under the following conditions.
a)

The elevators in the group do not serve an equal number of stops/floors.

The up-peak traffic is demanding.

There are multiple function areas in floors/mixed use buildings.

Tenants and visitors enrol to get into the building/office premises.

A DCS offers the following advantages over a conventional control system.
1) It improves the time to destination by grouping people travelling to the same

floors at learned intervals.

2) It results in organized lobby space, allowing more people to wait in the lobby.
3) It is able to perform express travel with fewer intervening stops.
4)

It improves system efficiency and handling capacity, allowing a group of

elevators to transport more passengers in a fixed period of time.

5) It allows terminals to be mounted away from the elevator lobby, reducing

congestion in the elevator lobbies.

A DCS offers the following disadvantages over a conventional control system.
i) It has a relatively lower performance during the lunchtime peak.
ii)

For correct and efficient operation of a DCS, each passenger needs to enter their

destination and not tail-gate. Groups of people tend to allow one person to enter

the destination floor, which means the DCS computes that there is only one

person when there could be two, three or more persons.

iii) It is not user-friendly for people unfamiliar with the system. A passenger getting

into the wrong elevator has to exit and take another elevator to reach their

destination.

Table D.40 sets out building types that benefit from a DCS compared to a

conventional control system.

Building type

Conventional system

Destination control system

Residential apartment – occupants are

familiar with the elevator system

Office – occupants are familiar with the

elevator system

P P

Hotel – occupants are unfamiliar with the

elevator system

Hotel apartment – occupants are

unfamiliar with the elevator system

Educational building – stairs are relied

upon to move between classes

Healthcare building (staff area) –

occupants are familiar with the elevator

system

Healthcare building (all other areas) –

mixture of occupants who are familiar and

unfamiliar with the elevator system

Table D.40 Recommendations for destination control systems in buildings

D.9.8.4

Hybrid systems

A hybrid system (historically called an up-peak booster) combines destination control

at the main boarding floor with conventional elevator controls at other floors. A

hybrid system should be used where it is necessary to overcome lag in a DCS during

peak lunchtime occupant circulation.

Dubai Building Code

Part D: Vertical transportation

D 40

D.10 Annex: Vertical transportation design summaries and report template

D.10.1 Vertical transportation selection

summary – Design method 1

Vertical transportation selection summary (Design method 1)

Project name

Form number

Location

Date

Plot no.
Client
Architect
Project type

Project classification

Design

Authority

Estimated population
Number of groups

Occupiable floors
Boarding floors including main lobby

Number of passenger elevators based on

population
Number of passenger elevators based on

boarding floors
Number of dedicated firefighting

elevators
Number of dedicated service elevators
Number of other elevators
Total elevators in the project
Number of escalators in the project
Number of moving walks in the project

Authority section

Comments

Reviewed by

Dubai Building Code

Part D: Vertical transportation

D 41

D.10.2 Vertical transportation design summary – Design method 2

Vertical transportation performance approval summary (Design method 2)

Project name

Plot #

Form #

Location

Date

Client
Architect
Project type

Project classification

Is there a VT Consultant

involved?

yes

Group 1

Morning

peak

Lunch

peak

Evening

peak

Estimated

population

Handling capacity

HC5%

Occupiable floors

Average waiting

time (s)

Boarding floors

including main lobby

Average destination

time (s)

Group 1 Group 2 Group 3

Group 2

Morning

peak

Lunch

peak

Evening

peak

Capacity

Handling capacity

HC5%

Speed

Average waiting

time (s)

Door open time

Average destination

time (s)

Door closing time
Acceleration
Jerk

Group 3

Number of

passenger elevators

Morning

peak

Lunch

peak

Evening

peak

Number of

passenger elevators/

fire/service elevators

Handling capacity

HC5%

Number of dedicated

firefighting elevators

Average waiting

time (s)

Number of dedicated

service elevators

Average destination

time (s)

Number of other

elevators
Total elevators in the

project
Total number of

escalators in the

project
Total number of

moving walks in the

project

Declaration: The vertical transportation system in the project is designed within the recommended

parameters, and the parameters selected shall be met by suppliers approved in the UAE.

Remarks by VT Consultant/Lead Consultant

Authority section

Comments:

Reviewed by

Approved by

Dubai Building Code

Part D: Vertical transportation

D 42

D.10.3 Vertical transportation report template for VT Consultants

Table D.41 gives a summary of the minimum information required in the report.

Summary of vertical transportation (VT) design report
Section A

Main report

Purpose of the report

Project overview

Assumptions

Design of vertical transportation (VT) system

Design elements for residences

Definitions of design parameters

Selection of passenger elevators

Selection of firefighting elevator

Selection of service and other elevators

A10

Conclusions and recommendations

Section B

Annexures

Codes and requirements of Authorities

Traffic analysis

Planning information

Requirements from Authorities

Table D.41 Summary of vertical transportation (VT) design report

Dubai Building Code

Part E: Building envelope

E 2

E.1 Performance statements

Performance statement

The performance statement will be met

by following the requirements of:

The building envelope shall safely resist

the loads imposed upon it.

E.4

The building envelope shall reduce the

energy required to cool the building.

E.5

The building envelope shall control

moisture to protect the building, its

users, its mechanical systems and its

contents from physical or chemical

damage.

E.7

The building envelope shall provide

external noise protection to occupants.

E.8

The building envelope shall provide

glazing that safely resists impact, whilst

incorporating measures to prevent

occupants colliding with the glazing.

E.9

The building envelope shall provide

a safe means of opening and closing

windows.

E.9

The building envelope shall adequately

guard against the spread of fire.

E.10

The building shall provide safe access

for cleaning and maintenance of the

building envelope.

E.12

Dubai Building Code

Part E: Building envelope

E 3

E.2

Definitions

E.2.1

Terms

Building elevation:

View showing the image of one side

of the building. A flat representation of one façade.

Building envelope:

Physical barrier between the

exterior and the conditioned environment of a building

to resist air, water, moisture, heat, cold, light, and noise

transfer. For an air-conditioned building, the building

envelope comprises the elements of a building that

separate conditioned spaces from the exterior. Crown

extensions to the façade to cover plant screen cladding

are part of the building envelope. The building envelope

does not include the physical barrier below ground.

Building maintenance unit:

Permanently installed

unit that provides easy and safe access to the building

envelope for maintenance, inspections and cleaning.

Containment:

Glass barrier resisting penetration and

preventing people from falling even after failure or

breakage.

Damp-proof course:

Layer of waterproof material or

construction in the wall of a building near the ground,

primarily to prevent rising damp.

Damp-proof membrane:

Material applied to prevent

moisture transmission.

Drained air space:

Air layer within a wall that allows

any entering water or moisture to be drained out.

Glazed element:

Individual element within a building

envelope that lets in light, including windows, plastic

panels, clerestories, skylights, doors that are more than

one half glass, and glass block walls.

Glazing:

Glass that is installed as one of the

components of a wall, floor, ceiling or roofing system.

Gross wall area:

Area of the wall that provides the

thermal barrier of the building. It includes the solid

area and any openings in the wall, such as doors

or windows. It is the actual measured area, not the

projected area on a drawing.

Groundwater pressure:

Pressure of groundwater held

within a soil or rock, in gaps between particles.

Guardrail:

Vertical protective barrier erected along

elevated walking surfaces, exposed edges of stairways,

balconies and similar areas that minimizes the

possibility of fall from elevated surfaces to lower level.

High-rise building:

Building height greater than or

equal to 23 m and up to 90 m, measured in accordance

with the UAE FLSC

[Ref. E.1]

. A more detailed

definition is given in UAE FLSC.

Interstitial condensation:

Condensation which occurs

within or between layers of a construction.

Light transmittance:

Percentage of incident light

that passes through the glazed elements. When this

percentage increases, the amount of daylight that

passes into the building will increase.

Low-rise building:

Building height less than or up to

15 m, measured in accordance with the UAE FLSC

[Ref. E.1]

. A more detailed definition is given in

UAE FLSC.

Manifestation:

Clear markings on transparent glazing

to enable occupants to see the glazing as a hazard to

be avoided.

Mid-rise building:

Building height greater than 15 m

but less than 23 m, measured in accordance with the

UAE FLSC

[Ref. E.1]

. A more detailed definition is

given in UAE FLSC.

Moisture:

Water or other liquid diffused in a small

quantity as vapour, within a solid, or condensed on a

surface.

Mould:

Type of fungus that grows on damp or decaying

material surfaces.

Operational forces:

Forces sustained by the building

envelope during operation of the building, e.g. impact

from equipment or occupants.

Rope access or abseiling:

Form of work positioning

that allows rope access technicians to descend,

ascend and traverse ropes for access and work while

suspended by their harness.

Shading coefficient (SC):

Ratio of solar heat gain at

normal incidence through glazing to that occurring

through an approximately 3 mm thick clear float glass.

Dubai Building Code

Part E: Building envelope

E 4

Shading device:

Projecting fixture that extends outside

the external wall of any building, or a cover (such as

a louver), to protect any door or window from rain or

solar effect.

Skylight or overhead glazing:

Glass or other

transparent or translucent glazing material installed at

a slope of 15° or more from vertical.

Solar reflectance index (SRI):

Index that combines

reflectivity and emissivity, measuring a material’s

ability to reject solar heat. SRI is defined such that a

standard black (reflectance 0.05 and emittance 0.90) is

0 and a standard white (reflectance 0.80 and emittance

0.90) is 100. Materials with higher SRI absorb less heat

and can reduce heat island effect.

Solid metal panels:

factory manufactured panel

consisting of solid metal skin or skins without a core.

Solid metal panels could be aluminium, steel, copper,

zinc, stainless steel, titanium, etc.

Surface condensation:

Condensation which occurs on a

visible surface within a building.

Super high-rise building:

Building height greater than

90 m, measured in accordance with the UAE FLSC

[Ref. E.1]

. A more detailed definition is given in

UAE FLSC.

Thermal bridge:

Component or assembly of

components penetrating through an otherwise

continuous thermal line through which heat is

transferred at a substantially higher rate than through

the surrounding envelope areas. Examples could be a

metal fastener, concrete beam, balcony slab or column.

Thermal insulation:

Materials/products or the

methods and processes used to reduce heat transfer.

Heat energy can be transferred by conduction,

convection or radiation. The flow of heat can

be delayed by addressing one or more of these

mechanisms and is dependent on the physical

properties of the material employed to do this.

Thermal transmittance:

Rate of transfer of heat

through a material(s) or assembly, expressed as a

U-value.

Vapour resistance layer:

Material layer within a wall or

roof build-up with a high resistance to moisture vapour.

Window-to-wall ratio (WWR):

Percentage determined

by dividing the glazed area by the total external wall

area of the building envelope. WWR can be calculation

per orientation or per entire building.

Dubai Building Code

Part E: Building envelope

E 5

E.2.2

Acronyms and abbreviations

ANSI

American National Standards Institute

ASCE

American Society of Civil Engineers

ASHRAE

American Society of Heating, Refrigeration, and

Air-Conditioning Engineers

ASTM

ASTM International

BMU

building maintenance unit

BRE

Building Research Establishment

British Standard

BS EN

British Standard European Norm

CFR

Code of Federal Regulations

Ch.

chapter

CPSC

Consumer Product Safety Commission

CWCT

Centre for Window and Cladding Technology

DCD

Dubai Civil Defence

ETA

European technical assessment

FFL

finished floor level

Factory Mutual

IBC

International Building Code

IRATA

Industrial Rope Access Trade Association

ISO

International Organization for Standardization

NFPA

National Fire Protection Association

photovoltaic

SRI

solar reflectance index

technical note

UAE FLSC

UAE Fire and Life Safety Code of Practice

Underwriters Laboratories

WWR

window to wall ratio

Dubai Building Code

Part E: Building envelope

E 6

E.3 References

E.3.1

Essential references

ANSI Z97.1, Safety glazing materials used in buildings
ASCE/SEI 7-16, Minimum design loads and associated

criteria for buildings and other structures

ASHRAE 90.1:2019, Energy standard for buildings

except low rise residential buildings
ASTM D1929, Standard test method for determining

ignition temperature of plastics
ASTM E1300, Standard practice for determining load

resistance of glass in buildings

ASTM E108, Standard test methods for fire tests of

roof coverings

ASTM E119, Standard test methods for fire tests of

building construction and materials
BS 5250, Code of practice for control of condensation

in building

BS 6262-4, Glazing for buildings – Part 4: Code of

practice for safety related to human impact
BS 8102, Code of practice for protection of below

ground structures against water from the ground

BS 8414-1, Fire performance of external cladding

systems – Part 1: Test method for non-loadbearing

external cladding systems fixed to, and supported by, a

masonry substrate

BS 8414-2, Fire performance of external cladding

systems – Part 2: Test method for non-loadbearing

external cladding systems fixed to and supported by a

structural steel frame

BS EN 12600, Glass in building – Pendulum test –

Impact test method and classification for flat glass
BS EN 13501-1, Fire classification of construction

products and building elements – Part 1: Classification

using data from reaction to fire tests
BS EN 13501-5, Fire classification of construction

products and building elements – Part 5: Classification

using data from external fire exposure to roofs tests
BS EN 1364-3, Fire resistance tests for non-

loadbearing elements – Curtain walling – Part 3: Full

configuration (complete assembly)
BS EN 1364-4, Fire resistance tests for non-

loadbearing elements – Curtain walling – Part 4: Part

configuration
FM 4881, Evaluating exterior wall systems
ISO 13785-2, Reaction-to-fire tests for façades –

Part 2: Large-scale test
NFPA 256, Standard methods of fire tests of roof

coverings

NFPA 276 Standard method of fire test for

determining the heat release rate of roofing assemblies

with combustible above-deck roofing components

NFPA 285, Standard fire test method for evaluation

of fire propagation characteristics of exterior wall

assemblies containing combustible components

UL 263, Standard for fire tests of building construction

and materials

UL 790, Standard for standard test methods for fire

tests of roof coverings

Ref. E.1

UAE MINISTRY OF INTERIOR GENERAL

COMMAND OF CIVIL DEFENCE, 2018. UAE Fire and

Life Safety Code of Practice (UAE FLSC). United Arab

Emirates: Ministry of Interior General Command of

Civil Defence.

Ref. E.2

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2005. Standard for systemised

building envelopes. Bath: CWCT.

Ref. E.3

INSTITUTION OF STRUCTURAL ENGINEERS,

2014. Structural use of glass in buildings. 2nd ed.

London: IStructE Ltd.

Ref. E.4

EUROPEAN ORGANISATION FOR

TECHNICAL APPROVALS, 2011. Guideline for

European technical approval for structural sealant

glazing systems (SSGS). ETAG 002. Brussels: EOTA.

Ref. E.5

INTERNATIONAL CODE COUNCIL, 2015.

International Building Code. Section 1404,

Section 1405 and Ch. 20 to 24. Washington: ICC.

Dubai Building Code

Part E: Building envelope

E 7

Ref. E.6

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2012. Impact performance of building

envelopes: Guidance on specification. Technical note 75

(TN 75). Bath: CWCT.

Ref. E.7

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2012. Impact performance of building

envelopes: Method for impact testing cladding panels.

Technical note 76 (TN 76). Bath, UK: CWCT.

Ref. E.8

BUILDING RESEARCH ESTABLISHMENT,

2006. Assessing the effects of thermal bridging at

junctions and around openings. IP 1/06.

Bracknell: BRE.

Ref. E.9

CONSUMER PRODUCT SAFETY

COMMISSION, 2016. Safety standard for architectural

glazing materials. 16 CFR 1201. Bethesda: CPSC.

Ref. E.10

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2019. Safety and fragility of glazed

roofing: Guidance on specification. Technical note 66

(TN 66). Bath: CWCT.

Ref. E.11

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2010. Safety and fragility of glazed

roofing: Testing and assessment. Technical note 67

(TN 67). Bath: CWCT.

Ref. E.12

BUILDING RESEARCH ESTABLISHMENT,

2013. Fire performance of external thermal insulation

for walls of multi-storey buildings. BR 135.

Watford: BRE.

Ref. E.13

CENTRE FOR WINDOW AND CLADDING

TECHNOLOGY, 2016. Assessing cradle and suspended

access equipment. Technical note 96 (TN 96).

Bath: CWCT.

Ref. E.14

INDUSTRIAL ROPE ACCESS TRADE

ASSOCIATION (IRATA), 2014. International Code of

Practice. Kent: IRATA International.

E.3.2

Further reading

INSTITUTION OF STRUCTURAL ENGINEERS, 2020.

Structural aspects of cladding. London: IStructE Ltd.

GREAT BRITAIN, 2013. The Building Regulations 2010,

Approved Document C: Site preparation and resistance

to contaminants and moisture. 2004 ed. with 2010

and 2013 amendments. London: The National Building

Specification (NBS).

GREAT BRITAIN, 2013. The Building Regulations 2010,

Approved Document K: Protection from falling collision

and impact. 2013 ed. London: The National Building

Specification (NBS).

Dubai Building Code

Part E: Building envelope

E 8

E.4 Structural

E.4.1

Strength and stability

E.4.1.1

General

Any part of the building envelope presents a hazard if it becomes detached from

the building. The building envelope and associated openings shall be designed and

constructed to safely resist the loads required by

Part F

and those mentioned in this

section.
The building envelope shall:
a) be capable of safely sustaining, and transmitting to the supporting structure

of the building, all static and dynamic design loads (i.e. dead, imposed,

thermal, seismic, wind, etc.) without fracture or permanent deterioration of its

performance;

be securely fixed to and supported by the structure of the building. This shall

comprise both vertical support and horizontal restraints;

c) be made, where necessary, to accommodate differential movement of the cladding

and the supporting structure of the building (such as differential settlement,

inter-storey drifts, etc.);

be of durable materials/products. The service life of the fixings shall be not less

than the building envelope design life. Fixings shall be corrosion-resistant and of a

material type appropriate for the local environment and exposure conditions;

e) not fully or partially detach from the building (although it may break under the life

safety structural performance level as described in

F.7.13

); and

f) not be a source of noise or be at risk of resonant excitation caused by wind.

E.4.1.2

Wind loadings

Wind load shall be calculated in accordance with

Part F

or by wind tunnel testing

carried out in accordance with

Part F

Test loads simulating wind loading shall be applied perpendicularly to the building

envelope at its weakest point.

NOTE: Pressure coefficients often vary across the building envelope. Higher pressure

is expected at corners.

E.4.1.3

Permanent fixture loading

Building envelopes which are intended to support permanent fixtures and/or building

maintenance equipment attached to either internal or external faces shall be capable

of withstanding, without excessive deflection or permanent deterioration of its

performance, the forces arising from these fixtures, including during use.

E.4.1.4

Operational forces

The building envelope shall be capable of sustaining and transferring the following

loads without any reduction in its performance:
a) a horizontal load applied on the surface of panels or on framing members in

accordance with Section 4.5.1 of ASCE/SEI 07-16;

b) a uniformly distributed load of 0.6 kN/m

or a 1 kN vertical load, whichever is the

most onerous, applied anywhere on internal ledges, horizontal framing members

or horizontal surfaces; and

c) loads resulting from the operation of cleaning cradles, anchor restraint points,

equipment or operators.

Parts of the building envelope protecting occupants from a change in level greater

than 760 mm shall either be designed to withstand the forces given in Section 4.5.1

of ASCE/SEI 7-16 or be provided with a guardrail in accordance with

B.4.2.5.2.

Balustrades and guardrails at balconies, terraces, roofs and changes in level greater

than 760 mm shall conform to

B.4.2.5.2

E.4.1.5

Thermal movements

The building envelope shall be capable of accommodating changes in dimension and

shape of its components resulting from changes in service temperatures, and from

differential service temperatures between the inside and outside of the building,

without any reduction in its performance.

Dubai Building Code

Part E: Building envelope

E 9

E.4.1.6

Deflection

Under the action of the most onerous combination of loads, the deflections of

building envelope components shall be limited such that no defect occurs, and

deflections are fully recovered after removal of loads.
The allowable limit deflection shall be determined by material properties, the distance

between points of attachment and the methods of attachment.

NOTE: The deflections given in Table E.1 are generally acceptable in line with Part 3

of the CWCT Standard for systemised building envelopes

[Ref. E.2]

Component

Measurement

Maximum deflection

Storey-height assemblies,

other than masonry

Between points of

attachment to structure

1/200 for span ≤ 3,000 mm

5 mm + 1/300 for
3,000 mm < span < 7,500 mm

1/250 for span ≥ 7,500 mm

Opaque infill panels

in secondary framing,

excluding glass

Between points of support

1/360 for brittle material such as stone
1/90 for non-brittle materials such as

aluminium or steel
Manufacturer recommendation shall also

be sought.

Framing containing glass:

Single glass
Insulating glass units

Between ends of frame
Between ends of unit

1/125 span of member
1/175 span of double-glazed unit
Manufacturer recommendation shall also

be sought.

Table E.1

Maximum recoverable deflection under design load

Deflection limits of main structural elements are given in

F.8

E.4.1.7

Fixings

Fixings to secure the building envelope shall be selected based on the proven

performance of the fixing. Manufacturer test data is generally determined using a

European technical assessment (ETA), a British Standard (BS), a European Norm

(EN) or an ASTM International (ASTM) standard.

The strength of fixings shall be selected based on tests using materials

representative of the material into which the fixing is to be anchored, taking account

of any inherent weaknesses that might affect the strength of the fixing (e.g. cracks in

concrete due to shrinkage and flexure, or voids in masonry construction).

The design of any component shall address the consequences of failure of any

individual fixing.
Fixings shall not be welded.

E.4.2

Structural use of glass

Glass used structurally, or glass that is not supported by load-bearing framing or that

is providing in-plane restraints to components, shall be designed with redundancy

in the system. The redundancy shall be such that if failure or breakage of the glass

occurs, the loading is shared by adjacent components.

NOTE: The Institution of Structural Engineer’s report on structural use of glass in

buildings

[Ref. E.3]

gives further guidance.

E.4.3

Structural use of silicone

The structural use of silicone in the building envelope shall be in accordance with

ETAG 002

[Ref. E.4]

Dubai Building Code

Part E: Building envelope

E 10

E.4.4

Materials

Building envelope materials and components shall meet the requirements given in

F.6

and IBC

[Ref. E.5]

, Section 1404, Section 1405 and Ch. 23 to Ch. 26.

The properties of glass used in the structural design shall be in accordance with

ASTM E1300.

E.4.5

Impact resistance

The building envelope shall be capable of withstanding applied or transferred impacts

that might occur during normal use (whether accidental, e.g. an object being kicked,

or deliberate, e.g. during maintenance) without sustaining damage that is not

repairable and without deterioration of its performance.
The test energy impacts for opaque areas should be not less than those given in

Table E.2, in accordance with CWCT TN 75

[Ref. E.6]

Soft and hard body testing shall follow the procedures in CWCT TN 76

[Ref. E.7]

Areas of

exposure

Description

Soft body

Hard body

Safety

Serviceability Safety

Serviceability

Areas within

1.5 m of ground

or adjacent

finished floor

level (FFL)

Area accessible to the

public and building users.

Chance of accident

occurring and of misuse.

500 J

120 J

10 J

Other accessible areas.

Some chance of accident

occurring or of misuse.

500 J

120 J

10 J

6 J

Areas between

1.5 m to 6 m

above ground

or above

adjacent FFL

Area liable to impacts

from thrown or kicked

objects.
Might also be subject

to impact during

maintenance which

might impose a higher

impact energy.

350 J

120 J

10 J

6 J

Areas more

than 6 m above

ground or

above adjacent

FFL

Area mainly subject

to impact during

maintenance which

might impose a higher

impact energy.

350 J

120 J

3 J

Table E.2 Exposure categories and minimum impact test energy for opaque areas

Dubai Building Code

Part E: Building envelope

E 12

E.5 Energy conservation

E.5.1

Energy compliance method

There are two compliance routes for energy performance, as shown in Figure E.1.
Where the performance method in Figure E.1 is to be used, the reference building

shall be equal in shape, size, orientation and operational patterns to the proposed

building. Calculation shall be determined in accordance with ASHRAE 90.1:2019,

Appendix G, except for the minimum requirements for building envelope, equipment

efficiencies and other parameters and conditions that are listed in the elemental

method in Figure E.1.

Compliance will be demonstrated if the annual energy consumption of the proposed

building is equal to or lower than the annual energy consumption of the

reference building.

Figure E.1 Flow chart for energy compliance method

ENERGY COMPLIANCE METHOD

ELEMENTAL METHOD

PERFORMANCE METHOD

All buildings shall conform to:

E.5.2.1 Maximum glazed area

E.5.2.2 Orientation of glazed facades

E.5.2.3 Building envelope

performance

H.4.8.1

Energy efficiency – HVAC

equipment and systems

H.7.2

Lighting power density –

Interior

Using a calculation tool such as

dynamic thermal modelling

Calculation shall compare the annual

energy consumption of the proposed

building with that of a reference

building.

Dubai Building Code

Part E: Building envelope

E 13

Figure E.2

Orientation of glazed façade

E.5.2

Elemental method requirements

E.5.2.1

Maximum glazed area

Except for shopfronts, the total WWR of glazed façades for conditioned spaces shall

not exceed:
a)

40% of the gross wall area for residential buildings; and

60% of the gross wall area for all other building types.

E.5.2.2

Orientation of glazed facades

For every orientation of the building, the percentage of the building elevation that

is glazed shall not exceed the values in Table E.3. Orientation shall be defined by the

angles in Table E.3 and as shown in Figure E.2.

Orientation of glazed element

Perpendicular angle from North

(

)

Percentage of glazing per

building elevation

North

−22.5° ≤

< 22.5°

≤80%

Northeast

22.5° ≤

< 67.5°

≤70%

East

67.5° ≤

< 112.5°

≤60%

Southeast

112.5° ≤

< 157.5°

≤40%

South

157.5° ≤

< 202.5°

≤40%

Southwest

202.5° ≤

< 247.5°

≤40%

West

247.5° ≤

< 292.5°

≤60%

Northwest

292.5° ≤

< 337.5°

≤70%

Table E.3 Window to external wall ratio based on orientation

Dubai Building Code

Part E: Building envelope

E 14

E.5.2.3

Building envelope performance

E.5.2.3.1 Non-glazed elements

With the exception of non-conditioned enclosed parking areas, the average thermal

transmittance for external walls, roofs, and exposed floors (the underside of the floor

is exposed to ambient conditions) shall not exceed the values in Table E.4 and

Figure E.3.

Figure E.3 Thermal transmittance for non-glazed elements of roof, external wall and exposed floor

≤

0.57 W/m

1 m

≤

0.57 W/m

≤

0.3 W/m

Table E.4

Thermal transmittance for non-glazed elements of roof, external wall and exposed floor

Element

Average thermal transmittance (W/m

Roof

≤0.3

External wall and exposed floor

≤0.57

While the U-value for external walls can be achieved using aerated concrete blocks,

the use of insulation for the entire building envelope is recommended. Insulation

materials shall conform to Sections 4 to 7, Ch. 1 of UAE FLSC

[Ref. E.1]

For the floor area that is in contact with the ground, the thermal transmittance

requirement shall be achieved by installing 1 m of perimeter insulation as shown in

Figure E.3.

Dubai Building Code

Part E: Building envelope

E 15

Glazed vertical surfaces Total glazed area

<40%

40% to 60%

>60%

Thermal transmittance

(U-value) in W/m

≤2.1

≤1.9

≤1.7

Shading coefficient

≤0.4

≤0.32

≤0.25

Light transmittance

≥40%

≥32%

≥25%

E.5.2.3.2 Glazed elements

The glazed elements shall meet the performance criteria in Table E.5. The total glazed

façade shall conform to E.5.2.1.

Shopfronts and showrooms

Required performance criteria

Thermal transmittance (U-value) in W/m

≤1.9

Shading coefficient

≤0.76

Table E.5 Performance criteria for glazed vertical surfaces based on total glazed area

Table E.6

Performance criteria for glazed shopfronts and showrooms, except ground floor

For shopfronts and showrooms, other than those at ground floor level, glazed

elements shall meet the performance criteria in Table E.6.

Skylights

Percentage of glazed roof based on total roof area

≤10%

>10%

Thermal transmittance (U-value) in W/m

≤1.9

Shading coefficient

≤0.32

≤0.25

Light transmittance

≥32%

≥25%

Table E.7 Performance criteria for a glazed roof based on total roof area

For skylights, the performance criteria in Table E.7 shall be met depending on the

area of glazing over the total roof area.

Thermal transmittance values are overall U-values for the glazed elements. Overall

U-values shall be calculated as the area-weighted averages of the centre of pane

U-value (glazing and panel) and frame U-value, including all edge effects (spacer and

frame) and thermal bridges. Glazed elements having back-insulated panels shall also

meet the thermal transmittance requirement, including framing, edges effects and

thermal bridges.

NOTE: The thermal transmittance of an insulating glass unit is higher when the

glazing is installed horizontally instead of vertically.

Dubai Building Code

Part E: Building envelope

E 16

Key

01: Vertical shading

02: Horizontal shading

E.5.3

Shade effect calculation

The use of external shading is recommended. The impact of external shading

(where used) and adjacent buildings can be taken into account when calculating

external load criteria. Examples of shading devices are shown in Figure E.4.

Figure E.4

Examples of shading arrangements

The impact of external shade factors on the building’s thermal load shall be

calculated when the performance method (see E.5.1) is used to verify energy

compliance.

E.5.4

Thermal bridges

For all new air-conditioned buildings, thermal bridges shall be either eliminated

or insulated to reduce the amount of heat transfer. Thermal bridging can occur at

connection points between concrete or steel beams, external walls and columns, and

around doors and windows (see Figure E.5).

NOTE: The BRE publication on assessing the effects of thermal bridging at junctions

and around openings

[Ref. E.8]

gives further details.

Figure E.5

Example of linear thermal bridge in buildings

Dubai Building Code

Part E: Building envelope

E 17

E.5.5

Durability

The building envelope shall be designed and specified to limit degradation due to

environmental factors throughout the design life of the building.

E.5.6

Sealing of windows and doors

Doors and window frames on the building exterior shall be sealed.

Sealing materials shall conform to Sections 4 to 7, Ch. 1 of UAE FLSC

[Ref. E.1]

. They

shall also prevent the transmission of air and sound that might occur as a result of

pressure differences across the exterior of the building. Air leakage shall be controlled

in accordance with

Part H.

Element

SRI value

Steep sloped roofs (slopes steeper than 1:6)

≥29

Flat and low sloped roofs (slopes lower than or equal to 1:6)

≥78

External walls

≥29

Table E.8 Building envelope SRI value requirements

SRI

≥

>1:6

≤

1:6

SRI

≥

SRI

≥

SRI

≥

Figure E.6

Illustration of SRI value requirements based on slope of roof

E.5.7

Heat island effect reduction

Opaque building envelope surfaces shall have a solar reflectance index (SRI) value

not less than that shown in Table E.8 and Figure E.6, for a minimum of 75% of the

roof area.

Dubai Building Code

Part E: Building envelope

E 18

E.5.8

Exterior light power, pollution and controls

The average lighting power density for the exterior connected lighting load for

building envelopes shall not exceed 2.2 W/m

for each illuminated wall or surface area

or 16.4 W/linear metre for each illuminated wall or surface length.
Permanently installed exterior lighting shall meet the following requirements.
a)

All exterior light fixtures on the building site, other than architectural accent

lighting (see E.5.8b) and Civil Aviation safety lighting, shall be shielded, such that

the full light emitted by the fixture, either directly or indirectly by reflection or

by refraction from any part of the fixture, is projected below the horizontal plane

passing through the lowest part of the fixture (see Figure E.7).

NOTE: Civil Aviation safety lighting is not covered in this Part.

b) Architectural accent lighting shall be aimed or shielded to prevent the lighting

of the night sky. Wall washing lights shall spill no more than 10% of the lighting

past the building façade.

c) Downward directed lighting shall be used for lighting of signage.
d)

All exterior lighting shall be fitted with automatic controls, so that the lights can

be set not to operate during daylight hours.

Figure E.7

Example of downward directed lighting projected below the horizontal plane of the lowest part of

the fixture

Dubai Building Code

Part E: Building envelope

E 19

E.6 Sustainable materials

E.7 Moisture

Construction materials shall be chosen in accordance with

B.10.6.

E.7.1

General

Moisture control is fundamental to the functioning of any building. Controlling

moisture is important to protect occupants from adverse health effects and to

protect the building, its mechanical systems and its contents from physical or

chemical damage.
The building envelope shall protect the building and occupants from:
a)  harmful effects caused by ground moisture;
b)  precipitation (including windblown spray); and
c)  the risk of interstitial or surface condensation.

E.7.2

Ground moisture

The building envelope walls shall:
a)  resist the passage of moisture from the ground to the inside of the building;
b)  not be damaged by moisture from the ground; and
c)  not carry moisture from the ground to any part of the building which could be

damaged.

For building envelope walls that are not subject to groundwater pressure, a damp-

proof course shall be provided at least 150 mm above the level of the adjoining

ground, as shown in Figure E.8, unless there is a part of the building design that

protects the wall. The damp-proof course shall be continuous with any damp-proof

membrane in the floor.

Dubai Building Code

Part E: Building envelope

E 20

Diagram 8 of the Building Regulations (2010), Approved Document Part C, 2004 Edition with 2010 and 2013

amendments. Contains public sector information licensed under the Open Government Licence v3.0)

Key

01: Out

02: In

03: Internal ground floor

04: Continuous damp proof course between wall and floor membrane

05: At least 150 mm if wall is an external wall

06: External ground floor

07: External pavement

08: Insulation

09: Compacted soil

10: Soil

Guidance on protection for building envelope walls that are subject to groundwater

pressure can be found in BS 8102.

E.7.3

Precipitation including windblown spray

E.7.3.1

General

The building envelope shall resist the penetration of precipitation:
a) to the inside of the building; and
b) to any part of the building envelope that might be damaged by moisture.

E.7.3.2

Horizontal and inclined surfaces

Horizontal surfaces or inclined surfaces within the building envelope (see Figure E.9)

shall:
a)  be jointless and impermeable to moisture; or
b)  have sealed joints and be impermeable to moisture; or
c)  have overlapping joints and either be impermeable to moisture or be backed by a

material that directs precipitation towards the outer face.

75°

Key

01: Vertical surfaces

02: Inclined surfaces

03: Horizontal surfaces

Figure E.9 Horizontal, inclined or vertical surfaces

Dubai Building Code

Part E: Building envelope

E 21

E.7.3.3

Vertical surfaces

Vertical surfaces within the building envelope (see Figure E.9) shall meet the

following requirements as appropriate to the external wall build-up type. Examples of

external wall build-up types are given in Figure E.10.

a) Solid external walls: The wall shall hold moisture arising from rainwater until the

moisture can be released in a dry period, without penetrating to the inside of the

building or causing damage to the building. If the wall is insulated, the insulation

shall provide resistance to the ingress of moisture to keep the wall dry.

b) Solid external walls with air cavities or with rainscreens: The outer leaf of an

external cavity wall shall either be separated from the inner leaf by a drained air

space, or prevent the precipitation from being carried to the inner leaf.

c) Curtain walling, doors and windows: Joints between curtain walling, doors,

windows and interfaces with other walls shall resist the penetration of

precipitation to the inside of the building. Joints shall not permit moisture to

reach any part of the building which could be damaged.

Figure E.10

Examples of external wall build-up types

Key

01: Cladding

02: Thermal insulation layer (vapour

resistance layer on the outer face)

03: Block wall

04: Plaster

05: Cavity

06: Glass

07: Framing

08: Plaster or gypsum board

09: Aerated blockwork

10: Out

11: In

(a) Solid external walls

(b) Windows, doors or curtain walls

(d) Solid external walls with cavaties

Dubai Building Code

Part E: Building envelope

E 22

E.7.3.4

Flashing

Flashing shall be installed to prevent moisture from entering the building envelope or

redirect moisture to the exterior. Flashing shall be installed at:

a)  perimeters of exterior door and window assemblies;
b)  penetrations and terminations of exterior wall assemblies;
c)  exterior wall intersections with roofs, balconies and similar projections; and
d)  built-in gutters from which moisture could enter the wall.

E.7.4

Risk of interstitial or surface condensation

The building envelope shall:
a) be designed and constructed such that its structural and thermal performance is

not adversely affected by interstitial condensation; and

b) not promote surface condensation or mould growth, for the given occupancy

conditions.

Technical solutions to minimize condensation risk depend on the wall type.
1) Curtain wall, skylight, doors and windows can incorporate thermal breaks in the

glazed framed systems.

2) Roofs and solid external walls can include a vapour resistance layer.
3) Interfaces and junctions between different elements of the building envelope

(such as windows) can ensure continuity of the vapour resistance layer by

extending and overlapping the vapour resistance layer between elements.

NOTE: BS 5250 gives further guidance on control of condensation in buildings. While

the guidance provides principles to control condensation, some commentary and

forms of construction given in the annexes might not be applicable to Dubai climate.

E.8 Acoustics

The building envelope shall meet the acoustic requirements given in

H.10.

Dubai Building Code

Part E: Building envelope

E 23

E.9 Protection from falling, collision and impact

E.9.1

Protection against impact with glazing

Safety glazing shall be installed in critical locations in doors, side panels and low level

glazing, as shown in Figure E.11 and Figure E.12.

5.1 of the Building Regulations (2010), Approved Document Part K, 2013 Edition. Contains public sector

information licensed under the Open Government Licence v3.0)

800

Regulations (2010), Approved Document Part K, 2013 Edition. Contains public sector information licensed

under the Open Government Licence v3.0)

Key

01: FFL

Key

01: FFL

In accordance with the Section 5, Ch. 1 of UAE FLSC

[Ref. E.1]

, safety glazing for use

in critical locations shall conform to the minimum classifications in either Table E.9 or

Table E.10.

Critical location

Height

Classification in test standard

BS EN 12600

Low level areas

All heights

Class 1

Doors

Below 900 mm from FFL

Class 2

Doors side panel

Above 900 mm from FFL

Class 3

Table E.9

Minimum classification for safety glazing

Area of glazing in critical

location (m

)

Classification in test standard

ANSI Z97.1

CPSC 16 CFR 1201 [Ref. E.9]

≤0.9

>0.9

Table E.10

Minimum classification for safety glazing

Dubai Building Code

Part E: Building envelope

E 24

E.9.2

Containment

Glazing at areas lower than 800 mm from FFL and protecting a change in level

greater than 760 mm shall provide containment, as shown in Figure E.13.

>760

800

Figure E.13

Examples of glazed areas that need to provide containment

Key

01: Internal FFL

02: External FFL

If a glazing panel covers areas above and below 800 mm from FFL, the entire glazing

panel shall provide containment.

E.9.3

Manifestation

Transparent glazing in the following locations shall incorporate manifestation

features:
a)  adjacent to doors;
b)  in doors without frames or handles; and
c)  in other areas where occupants might inadvertently come into contact with the

glazing.

The manifestation shall:

1) be located between 750 mm and 1,500 mm above FFL;
2) occupy a minimum of 50% of the area horizontally at each 900 mm width

interval, with minimum 50% opacity; and

3) contain visual elements of any type of bands or marks (such as logos and artistic

illustrations).

The manifestation should be permanent if possible, e.g. etching of the glazing, but

alternatively, if applied materials are used, they should be durable and not easily

removed.
Manifestation and visual detection elements are not required in the following cases:
i) where a glass surface is less than 500 mm wide;

ii) where the glass surface does not extend more than 850 mm above FFL;
iii) where a fixed element in front of the glass surface blocks the entire approaching

space; and

iv) where façade glazing is in upper floors with no access from outside, and where

there is no possibility of a user confusing it with access glazing.

Dubai Building Code

Part E: Building envelope

E 25

E.9.4

Safe opening and closing of windows

Sliding and operable windows shall be located at a height not less than 900 mm from

FFL.

Operable windows shall be restrained to limit the opening to 100 mm to prevent falls.
There shall not be any construction features at the bottom of the window that can be

exploited as a ladder or climbing feature.
Operable windows, skylights and ventilators shall be constructed or equipped such

that they can be opened, closed and adjusted safely. Wherever practicable, the height

of controls or handles shall be in accordance with

Part C

as indicated in Figure E.14.

If controls or handles cannot be positioned as indicated in Figure E.14, a manual or

electrical means of remote operation shall be provided in that location instead.

Figure E.14 Height of controls or handles

Key

01: FFL

E.9.5

Overhead glazing

Overhead glazing shall be laminated. It shall include a post-breakage containment

system, such that if the glass breaks, the glass is held in place until it can be replaced.
The safety and fragility of overhead glazing shall be determined in accordance with

CWCT TN 66

[Ref. E.10]

Overhead glazing shall be tested in accordance with CWCT TN 67

[Ref. E.11]

Dubai Building Code

Part E: Building envelope

E 26

E.10

Fire safety

E.10.1

General

The fire safety of the façade and roof elements of the building envelope shall conform

to Ch. 1 of UAE FLSC

[Ref. E.1]

and the specific requirements of this section.

To prevent external fire spread, the building shall be physically separated from

adjacent plots/buildings or the building envelope shall be fire resistance rated (see

Sections 2.7 and 2.8, Ch. 1 of UAE FLSC

[Ref. E.1]

The requirements for guardrails and balustrades as described in Section 2.17, Ch. 1

of UAE FLSC

[Ref. E.1]

are superseded by

B.4.2.5.2.

The requirements for safety glazing in Sections 5.4.2 to 5.4.4, Ch. 1 of

UAE FLSC

[Ref. E.1]

are superseded by E.9.

E.10.2

Sprinklers

Sprinklers on balconies, as mentioned by Ch. 9 of UAE FLSC

[Ref. E.1]

, are not

mandated by Dubai Civil Defence (DCD), provided that the materials of construction

of the balcony conform to Ch 1. of UAE FLSC

[Ref. E.1]

Sprinklers on the inside of rainscreen/glazing/curtainwall, as mentioned by

Ch. 9 of UAE FLSC

[Ref. E.1]

, are not mandated by DCD.

E.10.3

Spandrels

The fire resistance rated spandrel required by Section 2.8.10, Ch. 1 of

UAE FLSC

[Ref. E.1]

may be less than 915 mm, provided that the perimeter barrier

system in Section 3.2.4d is tested, certified and listed with the intended spandrel

specifications, complete with installation guidelines.

E.10.4

Fire testing of non-fire resistance rated, non-loadbearing

façades and aesthetic features/mashrabiya

The requirements in Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. E.1]

shall be met, with

the following amendments.
a)

The exceptions listed in Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. E.1]

are expanded

to include concrete, terracotta, glass, ceramics and mineral wool.

In addition to the materials listed in Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. E.1]

solid metal panels conforming to E.10.5 may be used.

The requirements in Section 4.5, Ch. 1 of UAE FLSC

[Ref. E.1]

shall be met, with the

following amendments.

1) Steel flashing is not required around window openings.
2) Flashing shall match the flashing included in the NFPA 285 fire test(s) forming

the basis of the fire safety design(s) of the façade.

Dubai Building Code

Part E: Building envelope

E 27

Table E.11

Fire test requirements for solid metal panels on non-fire resistance rated and non-load-bearing

building envelope and aesthetic features/mashrabiya

Occupancy and

type of building

Fire testing required for solid

metal panel

Fire testing required for façade assembly

Super high-rise

buildings

High-rise buildings

Malls
Theme parks
Schools

Hospitals

Assembly

Panel shall be tested in the

thickness intended to be used,

including any coatings to

BS EN 13501-1 with pass criteria

A1 or A2-s1-d0.

BS 8414-1 or BS 8414-2
with pass criteria in accordance with

BR 135

[Ref. E.12]

NFPA 285 with pass criteria “pass”

FM 4881 with pass criteria “pass”

or
ISO 13785-2 with pass criteria “pass”

Low-rise buildings

Mid-rise buildings
Warehouses
Industrial

Panel shall be tested in the

thickness intended to be used,

including any coatings to

BS EN 13501-1 with pass criteria

B-s1-d0.

BS 8414-1 or BS 8414-2
with pass criteria in accordance with

BR 135

[Ref. E.12]

NFPA 285 with pass criteria “pass”

FM 4881 with pass criteria “pass”

or
ISO 13785-2 with pass criteria “pass”

E.10.5

Solid metal panels

Solid metal panels (including any coatings) shall conform to Sections 4 to 7, Ch. 1

of UAE FLSC

[Ref. E.1]

. They shall also achieve the fire safety classifications and fire

safety performance criteria shown in Table E.11 to Table E.13 where applicable.

Table E.12

Fire test requirements for solid metal panel on a fire resistance rated exterior wall assembly

Occupancy and

type of building

Fire testing required for solid

metal panel

Fire testing required for façade assembly

Any building with

any height and any

occupancy

Panel shall be tested in the

thickness intended to be used,

including any coatings to

BS EN 13501-1 with pass criteria

A1 or A2-s1-d0.

ASTM E119
with pass criteria 1 h or 2 h or 3 h as per

required fire rating of the wall

UL 263

with pass criteria 1 h or 2 h or 3 h as per

required fire rating of the wall

or
BS EN 1364-3
with pass criteria 1 h or 2 h or 3 h as per

required fire rating of the wall

or
BS EN 1364-4
with pass criteria 1 h or 2 h or 3 h as per

required fire rating of the wall

Dubai Building Code (2021) - page 12