Approved Document

The framework for performance-based building code is set out in the Building Control Regulations 2003 (referred to in this Document as the Regulations). The Fifth Schedule of the Regulations sets out the objectives and performance requirements that must be complied with in the design and construction of building works (referred to in this Document as “prescribed objectives and performance requirements”). The objectives set out community expectations of a safe, accessible and energy efficient building. The performance requirements outline the level of performance, which must be met in order for a building to meet the objectives.

This Approved Document provides a set of ‘acceptable solutions’ that meet the prescribed objectives and performance requirements. The prescribed objectives and performance requirements are deemed to be satisfied if the design and construction of a building comply with the acceptable solutions.

Alternatively, a person may utilise alternative solutions in respect of the design and construction of any building if these solutions satisfy the prescribed objectives and performance requirements. Alternative solutions are solutions that entail the use of any design, material or construction method that differs completely or partially from those in the acceptable solutions.

The following abbreviations and symbols are used in this Document –

The objectives of paragraphs B.2.1 to B.2.4 are to –

1. protect people from injury caused by structural failure;

2. protect people from loss of amenity cause by structural failure; and

3. protect other property from physical damage caused by structural failure

A building, including its foundation, shall be designed and constructed so that the combined dead, imposed, wind and other intended loads can be sustained and transmitted by it to the ground –

1. safely; and

2. without causing such deflection or deformation of any part of that building, or such movement of the ground, as will impair the stability of any part of another building or property.

A floating structure on a body of water, including the foundation of the structure, must be designed and constructed so that the combined dead, imposed, wind and other intended loads can be sustained and transmitted by the floating structure to the body of water supporting the structure –

The building or structure shall be constructed with materials that are appropriate for the circumstances in which they are used.

Tests that are appropriate to the materials and building works concerned shall be performed on those materials and building works.

If a building or structure or any part thereof is to be demolished, the demolition works shall be carried out safely and without impairing the stability of any other part of that building or structure or another property.

The requirements in paragraphs B.2.1 to B.2.4 are deemed to be satisfied if the design and construction of a building comply with the specifications set out in paragraphs B.3.2 to B.3.7.

Structural design standards shall be based on the Eurocode design standards. Mixing the Eurocode design standards with the old superseded Singapore/British design standards within the same building design is not acceptable.

Any reference to the Eurocodes must be taken to include reference to the relevant Singapore National Annex listed in Annex A. However, in the absence of Singapore National Annex, reference shall be made to the relevant UK National Annex.

Similar to the design standards, the use of the Eurocodes will require the product and execution standards to be based on the equivalent Singapore/European standards.

The building shall be able to resist loads determined in accordance with the following Standards –

The design of the building structures shall comply with the following Standards –

The Design Qualified Person preparing plan shall design earth retaining or stabilizing structures in accordance with requirements listed below:

1. The structural elements of ERSS shall be designed with an adequate safety factor that is not less than that of permanent structural works carried out in the same project.

2. The allowable maximum wall deflection limits shall be limited to 0.5%H for Zone 1; 0.7%H for Zone 2; 0.7%H (Ground Type A) and 1.0%H (Ground Type B) for Zone 3, where –

   1. H is the excavation depth;

   2. Zone 1 is denoted as where there are existing structures within a distance of H from the edge of the excavation;

   3. Zone 2 is denoted as where there are existing structures within a zone of between H and 2H from the edge of the excavation.

   4. Zone 3 is denoted as where existing structures are more than 2H from the edge of the excavation. Ground Type A refers to overconsolidated stiff clays and silts, residual soils, and medium to dense sands; and Ground Type B refers to soft clays (including treated soft clays), silts or organic soils extending to or below formation level (e.g. Kallang Formation) and loose fills.

3. The allowable wall deflection limits shall also address the prevention of damage to neighbouring buildings or structures arising from ground deformations.

4. In any case, the QP shall adopt the more stringent value determined in b) and c) above and specify in the ERSS plan the allowable wall deflection as work suspension level (WSL) for inclinometer and 70% of WSL as the Alert Level. When the work suspension level is reached, work must be stopped, and immediate measures shall be implemented to remove any danger that is likely to cause a risk of injury or damage to adjoining properties.

5. To ensure the structural stability of the excavation system or to ensure the structural stability of the deep excavation system, the use of ground Building and Construction Authority Page 7 of 65 Approved Document – Acceptable Solutions V7.07 improvement measures such as jet grout piles (JGP), or grout mixed piles (GMP) or deep cement mixing (DCM) shall be restricted to ground strengthening or soil improvement works. It shall not be used as part of the support system or compressive strutting system or as embedded retaining walls. Movement during the installation of the ground improvement block or layer shall be monitored with appropriate allowable limits. If ground improvement layer is used to fulfil part of the stability requirement, the wall embedment shall be extended to such a depth that the minimum factor of safety (FOS) against basal heave of the ERSS alone (without consideration of ground improvement layer) shall be not less than 1.1.

Site investigation and instrumentation shall be carried out in accordance with the following Standards –

Site formation works shall conform to the Code of practice for earthworks – BS 6031.

The demolition works shall conform to the Code of Practice for Demolition – SS 557.

Construction materials shall comply with the following Standards –

Construction tests for the materials and the structural members or elements of a building shall comply with the following Standards –

The objectives of paragraphs C.2.1 are –

1. to protect people from injury caused by inadequate headroom; and

2. to prevent loss of amenity caused by inadequate height of room or space.

Any room or space in a building must be provided with –

1. adequate headroom; and

2. adequate height,

for the intended uses of the room or space.

The requirements in paragraph C.2.1(a) and (b) do not apply to any of the following rooms or spaces:

1. any attic that –

   1. does not exceed an area of 10 square metres; and

   2. is in a house that is built for the owner’s own use;

2. any equipment or plant room

3. the underside of any staircase or escalator if the staircase or escalator is not located along an access route or circulation space;

4. any toilet or bathroom in any house built for the owner’s own use;

5. any store room not exceeding an area of 6 square metres.

The requirement in paragraph C.2.1(b) does not apply to any of the following rooms or spaces:

1. any corridor or lobby;

2. any toilet, bathroom or powder room;

3. any localised area within a room or space where there is a drop in ceiling height due to physical constraints such as structural beams or building services.

The requirement in paragraph C.2.1 is deemed to be satisfied if the specifications set out in paragraphs C.3.2 and C.3.3 are complied with.

The headroom of every room, access route and circulation space shall not be less than 2.0 metres.

For sheltered car parks, the headroom at parking lots and driveway shall not be less than 2.2 metres.

The ceiling height of rooms and spaces shall not be less than 2.4 metres.

The objective of paragraphs D.2.1 to D.2.4 is to ensure that persons with disabilities are able to easily gain access to and exit from the whole or part of a building, and that persons with disabilities, children between 90cm and 120cm in height, caregivers of infants, and nursing women are able to carry out their activities within the building with reasonable ease.

At least one access route shall have barrier-free features to enable persons with disabilities to –

1. approach the building or the vehicle park; and

2. have access to those spaces where they may be expected to work or visit.

Sanitary facilities that are appropriate for use by persons with disabilities and sanitary facilities that are appropriate for use by children between 90cm and 120cm in height shall be adequately provided for use by such persons.

Appropriate facilities for lactation and changing of diapers shall be adequately provided and be accessible for use by nursing women and caregivers of infants.

Appropriate wayfinding guides such as signages or audible or tactile information providing directions or instructions shall be adequately provided within a building to guide persons with disabilities to spaces or facilities where or which they may be expected to work, visit or use.

The requirements in paragraphs D.2.1 to D.2.4 are deemed to be satisfied if the provisions and facilities for persons with disabilities, children between 90cm and 120cm in height, caregivers of infants, and nursing women comply with the Code on Accessibility in the Built Environment issued by the Commissioner of Building Control.

The objective of paragraphs E.2.1 and E.2.2 is to protect people from injury and to facilitate access during movement from one level to another in a building.

A staircase (including a flight of 2 steps or more) shall provide a safe and suitable passage for movement of people.

A staircase must have –

1. handrails or guides to assist movement (in accordance with paragraph E.3.6.1);

2. landings to break a fall and provide a place for rest;

3. sufficient width, tread and riser to avoid injury;

4. sufficient headroom to avoid injury; and

5. barriers to prevent people from falling off the edge of any open side that has a drop of 1,000 mm or more

The requirement in paragraph E.2.2(a) does not apply to a staircase located in any of the following rooms or spaces:

1. any equipment or plant room;

2. any production area of an industrial building; and

3. any house built for the owner’s own use

The requirements in paragraph E.2.2(b) and (c) do not apply to a staircase located in any of the following rooms or spaces:

1. any equipment or plant room;

2. any production area of an industrial building;

3. any attic that –

   1. does not exceed an area of 10 square metres; and

   2. is in a residential building;

4. any house built for the owner’s own use.

The requirements in paragraphs E.2.1 and E.2.2 are deemed to be satisfied if a staircase is designed and constructed in accordance with the specifications set out in paragraphs E.3.2 to E.3.7.

No projection, other than handrails, is allowed into the space of a staircase that is within a height of 2.0 m from the landing or pitch line.

The clear width of every staircase shall not be less than 1000 mm.

The height of a riser shall not be more than 175 mm. (see Figure E.3.4.2(a) for measurement of “riser”)

The width of a tread of a staircase (see Figure E.3.4.2(a) for measurement of “tread”) shall not be less than:

1. 225 mm, if the staircase is in a residential unit within a residential building;

2. 250 mm, if the staircase is in an industrial building; or

3. 275 mm, if the staircase is in any other type of building, including common staircases in a residential building.

The width of the tread of any tapered step shall be measured at a distance of 500 mm from the narrower end.

The risers and treads within each flight of stairs shall be of uniform height and size.

A landing shall be provided at every floor level and door opening.

Except for spiral staircases, an intermediate landing shall be provided in between floor levels at intervals of not more than 18 risers.

The clear width of any landing shall not be less than 1000 mm. See Figure E.3.5.3(a) and (b) on how to measure landing width.

A landing shall not have any step or drop. A winder does not constitute a landing and is only allowed in a residential unit, where one winder is allowed in every 90 degrees turn in the staircase with a minimum of one tread in between. See Fig. E.3.5.4 on acceptable winder layout.

A handrail shall be provided on at least one side of the flight of any staircase with more than 5 steps.

The height of the handrail shall be between 800 mm and 1000 mm above the pitch line.

Handrails shall:

1. have a circular section from 32 mm to 50 mm in diameter or an equivalent gripping surface as shown in Code on Accessibility in the Built Environment ; and

2. have a clear space between the handrail and all wall surfaces as shown in Figure E.3.6.3(a) of –

   1. not less than 40 mm; or

   2. not less than 60 mm where the wall has a rough surface.

A recess containing a handrail shall extend at least 450mm above the top of the rail as shown in Figure E.3.6.4(a).

A handrail shall be continuous throughout the entire length of stairs and the ends of the handrail should be properly formed or rounded off so that they do not pose a danger to the user.

Stair nosing must not project beyond the face of the riser and the riser may be vertical or have a splay backwards up to a maximum 25 mm, as shown in Fig E.3.7.1(a).

All steps must be fitted with nosing strips between 50 mm and 75 mm in width.

Nosing strips must be of a colour that contrasts with the steps to make the drop edge of each step clearly visible.

Painting of a nosing strip to achieve the colour contrast mentioned in subparagraph E.3.7.3 is not acceptable.

The objective of paragraphs F.2.1 and F.2.2 is to protect people from injury or loss of amenity due to lack of lighting, whether natural or artificial.

Lighting shall be adequately provided in a building for its intended purpose.

Residential buildings, other than houses built by the owners for their own use, shall be provided with natural lighting for the purpose of paragraph F.2.1.

Despite paragraph F.2.2, artificial lighting may be provided to any of the following rooms or spaces in a residential unit, instead of natural lighting –

1. any toilet or bathroom;

2. any store room;

3. any basement;

4. any civil defence shelter.

The requirement in paragraph F.2.1 is deemed to be satisfied if –

1. natural lighting that complies with paragraph F.3.2.1; or

2. artificial lighting that complies with the recommended illuminance given in SS 531 - Code of Practice for Lighting of Work Places.

is provided.

Natural lighting shall be provided by means of one or more windows or other openings with an aggregate light transmitting area of not less than 10% of the floor area of the room or space required to be lighted.

The objective of paragraphs G.2.1 and G.2.2 is to protect people from loss of amenity due to lack of fresh air.

Ventilation shall be adequately provided in a building for its intended occupancy.

Residential buildings, other than houses built by the owners for their own use, shall be provided with natural ventilation for the purpose of paragraph G.2.1.

The requirement in paragraph G.2.1 does not apply to any of the following rooms or spaces not exceeding an area of 6 square metres –

1. any store room;

2. any private lift lobby;

3. any walk-in wardrobe;

Despite paragraph G.2.2, mechanical ventilation may be provided to any of the following rooms or spaces in any residential development:

1. any fitness room forming part of the communal area or common property;

2. any clubhouse;

3. any civil defence shelter;

4. any toilet or bathroom;

5. any basement.

The requirement in paragraph G.2.1 is deemed to be satisfied if –

1. natural ventilation that complies with paragraphs G.3.2.1 and G.3.2.2; or

2. mechanical ventilation that complies with the ventilation rates given in SS 553 - Code of Practice for Air-Conditioning and Mechanical Ventilation in Buildings; or

3. air-conditioning system that complies with –

   (for new erections of non-residential buildings)

   1. the ventilation rates given in SS 553 – Code of Practice for Air-Conditioning and Mechanical Ventilation in Buildings; and

   2. the Minimum Efficiency Reporting Value (MERV) for cleaning the air given in SS 553 – Code of Practice for Air-Conditioning and Mechanical Ventilation in Buildings (for all other types of building works) the ventilation rates given in SS 553 – Code of Practice for Air-Conditioning and Mechanical Ventilation in Buildings,

   (for all other types of building works)

   ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎the ventilation rates given in SS 553 – Code of Practice for AirConditioning and Mechanical Ventilation in Buildings,

is provided.

Natural ventilation shall be provided by means of one or more openable windows or other openings with an aggregate effective open area of not less than –

1. 5% of the floor area of the room or space required to be ventilated; and

2. in the case of an aboveground car park, comply with relevant clause in SS553 – Code of Practice for Air-Conditioning and Mechanical Ventilation in Buildings.

All windows and openings intended for natural ventilation shall be located such that they open to –

1. the exterior of the building;

2. an airwell with a minimum width of 3.0m and a minimum area open to the sky complying with Table G.3.2.2(a); or

3. a recess, exceeding 3.0m from the external building wall, and of minimum width 3.0m. See Figure G.3.2.2(b) for illustration.
   

   Height of airwell	Minimum airwell size (m2 )
   Not more than 30 m	10
   For each additional 3m height, or part of, beyond 30 m	Add 1 to the minimum size of 10

Table G.3.2.2(a) – Dimension of airwells

No part of any room or space (other than a room in a warehouse) that is designed for natural ventilation shall be located more than 12 metres from any window or opening that is used to ventilate the room or space.

The objective of paragraphs H.2.1, H.2.1A and H.2.1B is to protect people from injury caused by falling from a height.

Where there is a vertical drop in level of 1.0 m or more, appropriate measures shall be taken to prevent people from falling from a height.

Where a barrier is installed to prevent a person from falling from a height, the barrier –

1. must be sufficiently high to prevent a person from falling over the top of the barrier;

2. must not have any opening or gap that will allow a person to slip through the barrier; and

3. must not have any feature that facilitates a person in climbing over the barrier.

Where glass is used as a part or whole of a barrier, the glass used shall be able to withstand the loading for which it is designed and shall not be susceptible to spontaneous breakage or to shattering.

The requirement in paragraphs H.2.1, H.2.1A and H.2.1B do not apply to –

1. any roof or maintenance area which is not easily accessible; and

2. any area where the provision of a barrier would prevent it from being used as intended, such as a loading dock or pier, platform for the loading or unloading of goods, or for boarding or alighting of passengers, stage for performance or entertainment, golf driving range, equipment pit and the like.

The requirement in paragraph H.2.1A(a) does not apply to a barrier installed in any house built for the owner’s own use.

The requirement in paragraph H.2.1A(b) does not apply to a barrier installed in any of the following places:

1. any promenade or boardwalk at ground level along a waterfront;

2. any houses built for the owner’s own use.

The requirements under paragraph H.2.1A(c) does not apply to –

1. any industrial building;

2. any promenade or boardwalk at ground level along a waterfront;

3. any bay window in a residential unit;

4. any house built for the owner’s own use.

The requirement in paragraphs H.2.1, H.2.1A and H.2.1B is deemed to be satisfied if a barrier is provided in accordance with the specifications set out in paragraphs H.3.2 to H.3.5.

The requirements in paragraphs H.2.1, H.2.1A and H.2.1B are deemed to be satisfied for a safety barrier integrated with window at existing residential buildings, if such safety barrier is in accordance with the standardised design.

The height of a barrier shall not be less than –

1. 1.0 metre; or

2. 900 mm at the lower edge of the window and gallery or balcony with fixed seating in areas such as theatres, cinemas and assembling halls.

A barrier shall be designed to withstand a horizontal loading determined in accordance with SS EN 1991 Actions on structures – Part 1-1: General actions – Densities, self-weight, imposed loads for buildings and the associated Singapore National Annex.

Glass panel barriers shall be designed and installed in accordance with Section 8 of BS 6180 – Barriers in and about Buildings – Code of Practice.

There must not be any gap, from the finished floor level to a height no less than 75 mm, at the lowest part of a barrier.

The lowest 75 mm section of a bay window shall not be openable.

The size of any opening or gap in a barrier must not be large enough as to permit the passage of –

1. in the case of non-industrial buildings, a 100 mm diameter sphere;

2. in the case of industrial buildings, a 150 mm diameter sphere, or

3. in the case of maintenance areas, including plants, equipment rooms, catwalks or maintenance platforms that are accessible only by authorised personnel, a 500 mm diameter sphere.

For any flight of staircase –

1. the gap size between any two consecutive steps in a flight of staircases shall not be large enough as to permit the passage of –

   1. in the case of industrial buildings, a 150 mm diameter sphere, or

   2. in the case of all other buildings, a 100 mm diameter sphere

2. the size of any triangular opening, gap or void formed around a tread, riser and bottom edge of the barrier at a staircase in any building other than an industrial building shall not be large enough as to permit the passage of a 150 mm diameter sphere.

A barrier must have a height no less than –

1. the height specified in paragraph H.3.2.1, or

2. 850 mm when measured from the last climbable toehold

whichever is higher.

See Figure H.3.4A.1(a) for illustration.

Where glass is used as a part or whole of a barrier, laminated glass shall be used.

All glass used must comply with SS 341: Specification for Safety Glazing Materials for Use in Buildings.

Section deleted and streamlined under the Building Control (Environmental Sustainability) Regulations 2008 (“BC (ES) Regulations”).

The objective of paragraph J.2.1 is to protect the roof of semi-detached houses, terraced houses and linked houses from physical damage when repairs, alterations or additions to the roof of an adjoining house are being carried out.

The roof shall be designed and constructed such that the roof of every house is separate and independent of each other.

The requirement in paragraph J.2.1 is deemed to be satisfied if the party wall is extended above the level of the roof so that each roof is separate and independent of the roof of the adjoining house.

The objectives of paragraphs K.2.1 is to provide a convenient means of vertical transportation.

A building comprising 5 or more storeys (including the ground level and any basement level) must be provided with at least one passenger lift.

The objective of paragraph L.2.1 is to protect a building against physical damage caused by lightning strike and to protect its occupants from the risk of lightning current being discharged through the building.

A lightning protection system must be capable of protecting the building against lightning strike and protecting the occupants of the building from being exposed to any lightning current that is discharged through that buildings.

The requirement in paragraph L.2.1 is deemed to be satisfied if the lightning protection system

1. is designed and installed in accordance with Part 1, Part 2 and Part 3 of SS 555 – Singapore Standard for Protection Against Lightning; and

2. is of a minimum level of Class III lightning protection system as described under SS 555 – Singapore Standard for Protection Against Lightning.

The objective of paragraphs M.2.1 and M.2.2 is to protect people from injury caused by falling windows.

A window system shall be adequately designed and constructed with appropriate materials for its intended use.

A window system shall have –

1. window components, including fasteners, fixings, hinges and stays of adequate number, size and strength to safely support the weight of the window system and other loads imposed on it;

2. a structural frame profile that is of adequate size and strength and adequately reinforced at locations where screws or rivets are to be affixed; and

3. features and components to prevent the window from detaching, dislodging or falling during its intended use.

In the case of an aluminium alloy window, the requirements in paragraphs M.2.1 and M.2.2 are deemed to be satisfied if such window is designed and constructed in accordance with SS 212 – Specification for Aluminium Alloy Windows.

The objective of paragraph N2 is to protect persons from injury cause by spontaneous breakage of glass elements at height and by falling glass panels resulting from bond failure of structural sealant.

Where glass is used as a part or whole of the facade, roof, canopy or other type of overhead glazing of a building located at height of 2.4 metres or more, whether situated within the interior or forming the exterior of a building, appropriate measures shall be taken to minimise the risk of injury to people in the event of spontaneous breakage of such glass elements.

Where structural sealant glazing is used in a glass curtain wall or other glass installation located at a height of 2.4 metres or more, whether situated within the interior or forming the exterior of a building, appropriate measures shall be taken to minimise the risk of injury to people in the event of falling glass panels resulting from bond failure of the structural sealant.

Spontaneous breakage of glass

The requirement in paragraphs N.2.1 is deemed to be satisfied if the specifications set out in paragraphs N.3.2 to N.3.4 are complied with.

Except as provided in N.3.3, float (or annealed) glass, heat strengthened glass, laminated glass or other type of glass that is not prone to spontaneous breakage shall be used as the glass material at height.

Where monolithic tempered glass, heat-soaked tempered glass or other types of glass that are prone to spontaneous breakage is used in the facade, roof, canopy or other type of overhead glazing located at a height of 2.4 metres or more, the design of the facade, roof, canopy or overhead glazing shall provide for suitable protection such as installation of screens or shields to protect people from any injury in the event of breakage of such glass elements at height.

Where the glass is used as a part or whole of the facade, roof, canopy or other type of overhead glazing, the glass used shall comply with SS 341: Specification for Safety Glazing Materials for Use in Buildings.

Falling glass resulting from bond failure of the structural sealant

The requirement in paragraph N.2.2 is deemed to be satisfied if the specifications set out in paragraphs N.3.6 to N.3.8 are complied with.

The structural sealant glazing (SSG) shall be constructed to be of

1. two-sided SSG type; or

2. four-sided SSG type with retaining devices that are to be designed and constructed to prevent any fall of façade panels in the event of bond failure of the structural sealant.

Mechanical self-weight supports shall be provided for all glass panels of the SSG.

The SSG shall be designed and constructed in accordance with the following Standards –

1. ASTM C1184: Standard Specification for Structural Silicone Sealants and ASTM C1401: Standard Guide for Structural Sealant Glazing; or

2. BS EN 13022-2: Glass in Building - Structural Sealant Glazing and BS EN 15434: Glass in Building – Product Standard for Structural and/or Ultraviolet Resistant Sealant.

The objectives of paragraphs O.2.1 and O.2.2 are to protect people from injury caused by a vehicle breaching designated spaces for vehicular access in a building.

Where the whole or part of a floor of a building allows vehicular access, such as a vehicle park or a ramp or route for vehicular access, appropriate barriers shall be installed to prevent vehicles from breaching the perimeter of the floor of the building.

Where any part of a building allows vehicular access near an area where people are likely to be present, such as passenger pick-up point, vehicle park lift lobby and the like, appropriate measures shall be taken to prevent vehicles from encroaching into such areas.

The requirements in paragraphs O.2.1 and O.2.2 are deemed to be satisfied if a barrier is provided in accordance with the specifications set out in paragraph O.3.2.

The vehicular barrier should be capable of resisting forces set out in SS EN 1991.

The objective of paragraph P.2.1 is to protect occupants of buildings in the vicinity of a building from loss of amenity caused by the reflection of sunlight off the external surface of that building, arising from the use of materials with high daylight reflectance.

The external surface (including a roof) of a building must be designed and constructed in a manner such that any reflection of sunlight off the external surface of the building does not result in loss of amenity to occupants of other buildings in the vicinity of that building.

The requirement in paragraph P.2.1 is deemed to be satisfied if the specifications set out in paragraphs P.3.2 to P.3.3 are complied with.

The material used for the building work is deemed acceptable if –

1. the glass for the building work has a daylight reflectance not exceeding 20%

2. any material, other than glass and paint on plastered or concrete surfaces, for the building work on –

   1. the façade of the building has a specular reflectance not exceeding 10%

   2. the roof of the building, inclined at an angle not exceeding 20 degrees from the horizontal plane, has a specular reflectance not exceeding 10%

   3. the roof of the building, inclined at an angle more than 20 degrees from the horizontal plane, has a daylight reflectance not exceeding 20% and a specular reflectance not exceeding 10%

3. emulsion paint on plastered or concrete surfaces has a specular reflectance not exceeding 10%

The testing of reflectance values for any material shall be conducted in accordance with ASTM E903: Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres, or equivalent, with an integrating sphere of minimum 150mm diameter.

Note: * - There is no UK National Annex for this part of the Eurocode.

The contractor shall ensure the specifications in the following General Notes are complied with.

List of Drawings

1. The Contractor shall check all drawings and verify dimensions on site prior to commencement of work.

2. All workmanship and materials shall be in strict compliance with the latest current editions of Singapore Standards

3. The Contractor shall be responsible for the design of structural steel works at the fabrication stage, transportation stage and installation stage.

4. All dimensions shall be in millimeters or meter metric.

5. The total height of full height window frame shall be less than or equal to 2.65m for all type of windows including sliding windows and casement windows.

6. The total height of 3/4 height window frame shall be less than or equal to 2.05m for all type of windows including sliding windows and casement windows.

7. Maximum fixed glass panels width shall be equal or less than 1.0m for all type of windows including sliding windows and casement windows.

8. All cement grout shall be high strength non-shrink grout with minimum compression strength of 30MPa (7 days).

9. The contractor shall ensure that all the existing concrete strength shall be minimum grade C16/20.

10. Works shall be carried out in accordance with SS 212 Specification for Aluminium Alloy Windows and SS 341 Specification for Safety Glazing Materials for Use in Buildings.

11. Contractor shall put in place measures to prevent water leakage into the residential unit.

12. For demolition of existing safety barrier, method and construction of the demolition works shall be in accordance with SS 557:2010.

13. Contractor shall ensure that total window height ≤2.65m for all types of windows.

14. Contractor is to ensure that top and bottom surface where the anchor bolts are to be installed are RC structure.

1. All steel sections shall be with material grade S275 unless otherwise stated and all the steel materials are designed to conforming with BS EN 1993 and compliance to BC1-2012 Class 1.

2. Quality of structural steel shall conform to Eurocode EN1993 and shall be obtained from an approved manufacturer.

3. The contractor shall propose the erection procedures at their own expense including stability system and calculations for the engineer to review and comment before proceeding with the erection. The contractor shall ensure the structural steel works is stable throughout the construction, paying attention to the safe erection of structural steelworks is accordance with EN1090.

4. It will be the responsibility of the contractor to provide adequate shoring and bracing during construction to take care of wind load and other loads during construction.

5. The contractors shall verify all the dimensions by measuring at the site and resolve all the discrepancies before commencement of the fabrication works.

6. All steelwork shall be hot-dip galvanized.

1. All aluminium mullions and transoms shall be minimum RHS 100x50x3mm with material grade 6061-T6. Other sections shall be with material grade 6063-T5 designed to conforming with BS EN 1999-1-1, BS EN 1999-1-3 and BS EN 1999-1-4.

2. All aluminium sections shall refer to table below or equivalent,

   	Characteristic value of 0.2% proof strength	Characteristic value of ultimate tensile strength
   6061-T6	240 N/mm²	260 N/mm²
   6063-T5	110 N/mm²	160 N/mm²

3. Rubber separator shall be provided between other sections which are different materials from aluminium to prevent galvanized corrosion.

1. All visible surface of aluminium sections and other surfaces exposed to external environmental condition or visually shall be deemed to be coated PVDF2 (Primer: 5-10 microns; Colour: 30 micron; Clear: 10 microns) with approved Accredited Applicator.

2. Daylight Reflectance of the surface to comply with BCA requirement.

3. The paint system shall be maintenance free with the exception of regular cleaning as prescribed, be durable and have a colourfast of at least 20 years. The contractor shall collate comprehensive maintenance requirements from both paint manufacturer and the PVF 2 coating applicator for inclusion into the maintenance manuals.

4. The colour coat shall not contain less than 70% polyvinylidene fluoride.

5. The cured film shall be dense and consistent, with no seeding and free from flow lines, steaks, pin holes, blister, tear damage and other coating defects/surface imperfections when viewed from a distance of 1m under diffused daylight.

6. Prior to commencement of coating, Contractor shall submit samples showing the variations in colour and texture for confirmation.

1. All bolts, nuts and washers shall be stainless steel unless otherwise stated.

2. Material data of A4-70 stainless steel bolts, nuts & screws

   	Shear Strength	Tension Strength	Bearing Strength	Yield Strength	Tensile Strength
   A4-70	310 N/mm²	373 kN/m²	828 kN/m²	450 kN/m²	700 kN/m²

3. All stainless steel fasteners bolts and nuts shall be nonmagnetic grade A4-70 as per SS EN 1993-1-4.

4. All stainless steel screws shall be non-magnetic grade A4-70 as per SS EN 1993-1-4.

5. All stainless steel screws shall be minimum M5 self-tapping screws at maximum spacing 400mm c/c unless otherwise stated.

6. Minimum edge distance of screws shall be 15mm unless otherwise stated.

7. Minimum spacing of screws shall be 25mm unless otherwise stated

8. All anchor bolts to concrete shall be stainless steel unless otherwise stated in the drawings.

9. Minimum concrete edge distance of the anchor bolts shall be 100mm unless otherwise stated.

10. Minimum spacing of the anchor bolts shall be 75mm unless otherwise stated.

1. All setting blocks shall be 85±5, shore a durometer santoprene no less than 150mm long panel 1/4 points unless otherwise stated.

2. All glazing works shall comply to ASTM E1300-09a Standard Practice for Determine Load Resistance of Glass in Buildings

3. All glazing works shall comply to Section 8 of BS 6180: Barriers in and about Buildings - Code of Practice.

4. Allowable stress of heat-strengthen (HS) glass shall be minimum 32MPa.

5. All the 13.52mm thick laminated glazing as 6mm thick heat-strengthen glass + 1.52mm thick PVB + 6mm thick heat-strengthen glass for full height windows.

6. All the 9.52mm thick laminated glazing as 4mm thick heat-strengthen glass + 1.52mm thick PVB + 4mm thick heat-strengthen glass for 3/4 height windows.

1. The Contractor must ensure that the silicone proposed is compatible with the type of glass and cladding used for the project.

2. Testing by the sealant manufacturer for compatibility, adhesion and staining for all substrates in contact with the sealant must be completed successfully.

3. Oil base sealants are not acceptable.

4. Records for sealant batch number and date of manufacturer, as well as units to which the sealant is applied shall be maintained and made available upon request.

5. All sealant, in so far as practical for the weather and structural integrity of the Exterior Wall System, should be supplied by one manufacturer with a reputable background in the sealant industry.

6. The Contractor shall maintain a sealant recommendation letter with endorsed details by the sealant manufacturer to ensure proper application and performance warrantee.

7. The Contractor shall maintain compatibility test of all material substrates interface with silicone sealant to ensure material compatibility and submission of laboratory report on sealant adhesion.

8. Non-structural (weatherseal) silicone to adopt shall be FS TI-S-001543A (COM-NBS) and ASTM C920, Type SIM, NS, Class 25 or equivalent.

9. The colour of weatherproof silicone sealant to be black or any standard colour from sealant manufacturer.

10. All weatherproof silicone sealant shall compatible with all substrates including PVB interlayer of laminated glass.

11. All external weather seal silicone shall be non-bleed non-stain sealant.

12. All weatherproof silicone sealant shall be with ±50% movement capacity.

13. Metal to metal shop joint or external facade shall be GE SCS9000 weather seal sealant or equivalent.

14. Silicone shall not be used to support dead weight of vertical glass or panels.

15. Where a test Prototype is subjected to 1.5 times design pressures and loads, the structural silicone and related structural components are required to withstand such loading without failure.

16. Weather sealant shall be applied at all screws’ locations after the erection.

1. All gaskets and weather-strips to be extruded EPDM compatible extruded rubber or equivalent when in contact with silicone sealants.

2. Interior/ Exterior Set (Dry) Gasket

   • The exterior "sponge" glazing gaskets shall be cellular complying with ASTM C50991, Option 2. Sponge gaskets shall have a hardness of 40 ±5 durometer Shore A and shall be compressed 20% to 35% in the final installed position.

   • The interior "wedge" glazing gasket shall be non-cellular complying with ASTM C864-90 Option 2. Wedge gaskets shall have a hardness of 75 ±5 durometer Shore A for hollow profiles and 60 ±5 for solid profiles.

   • Both gaskets shall be compatible for incidental point contact with structural or weather seal silicones.

3. Exterior Visual Gasket at Glass Butt Joint

   • Exterior visual gaskets at glass butt joints shall be silicone.

   • The design of these gaskets must prevent "roll out" or dislocation under all performance requirements.

4. Setting blocks

   • Shall be silicone-rubber or silicone compatible rubber. In the case of structural silicone glazing, dense extruded silicone with a Shore A hardness of 85 ±5 durometer.

   • Shall have a minimum length of 100mm and in accordance with BS 6262.

   • Minimum width shall correspond to the glass thickness and retaining member but, in no case, shall be less than the glass thickness at point of contact.

   • Shall be located at quarter points.

   • Shall be secured against migration

5. Backing rod

   • Only closed-cell (polyethylene) foam to be adopted as backing rod.

   • Must be compatible with sealants and substrate.

   • Use only round tools (no sharp edges) to install backing rod. Do not pierce the rod skin of closed-cell rod.

   • Use specially designed extruded silicone gaskets at the weather seal joints between any butt glazed laminated vision glass lights to protect the PVB interlayer from the silicone.

1. Dead load

   • Glass: 2700 kg/m³ Alum: 2700 kg/m³ Steel: 7850 kg/m³

2. Structural

   • Design wind pressure, WL: 1.5kN/m²

   • Horizontal uniformly distributed line load, BL: 0.74 kN/m

   • Horizontal infill load, BL: 1.0 kN/m²

   • Horizontal point load, BL: 0.5 kN

   • Aluminium/GMS to be separated by EPDM sheet or bituminous paint or equivalent

   • Aluminium/concrete to be separated by EPDM sheet or bituminous paint or equivalent