Windows

The objective is to a have a long lasting functioning window system offering good security, thermal performance,  acoustic performance and controlled ventilation:

• Windows are to be commercial grade integrated system that includes flexible options and configurations, including doors, sliding windows, awning windows, louvers and double-hung components.  PWD Suite N02 is such a DoE approved integrated system.
• The size and proportions of windows need to be carefully considered in the design to provide maximum efficiency and a balance between the ESD factors such as; maximising daylight in rooms but avoiding unnecessary solar heat gain and thermal loss etc.
• Window openings should be kept to lengths appropriate for the structural system.  The length of windows should consider the structural implications of long window lengths where the structure over the window opening and roof will need to be supported. Continuous runs of windows can be made up of a number of optimum length windows with columns in between to support roof framing or cladding over. Where brickwork above needs to be supported, keep window lengths down to an appropriate length for standard arch bars.
• Building regulations require that the thermal performance of the façade, the window size, glass type and arrangement be assessed to ensure that excessive amounts of energy are not required to maintain a suitable indoor environment.
• Fly screening must be provided in all schools to the doors, windows and other openings in food preparation, biology, and non-water-closet toilet spaces or where specifically nominated in the EFSG.
• Schools in localities where fly incidence constitutes a health hazard (especially trachoma or other nuisance) will require fly screens to all opening sashes.                           

Consult local DoE – Asset Management Unit (AMU)

• Sill Heights: Refer to DG / AREA / CRITICAL DIMENSIONS to recommended sill heights.

The safety of occupants is paramount where glass is being used, especially in areas subject to human impact.  Unless referred to below all glazing types and thickness are to comply with the relevant AS as a minimum.

Laminated safety glass is to be used in DoE schools for all external glazing.

Laminated safety glass is to be used in DoE schools for all internal glazing up to door head height.

Refer to DG / WINDOWS / GLAZING / GENERAL

Note: Standard thickness laminated safety glass (6.4mm) does not provide category C or above security on external glazing where it is possible to make a hole in the glass and reach through to open a window or door.

Refer to DG / SECURITY CATEGORIES FOR OPENINGS

Lexan is a polycarbonate type glazing sheet that has good safety and security characteristics, but scratches more easily than glass.  It is very tough and when it finally breaks, the particles tend to be light, blunt and comparatively harmless. 

Lexan’s advantage over glass is in withstanding structural movement because of its greater flexibility.  However, Lexan could cost significantly more than glass.. Hence Lexan is only to be used where the glazing frame will be subject to excessive distortion, or where major security is necessary (e.g. in areas where repeated illegal entry or vandalism have been experienced in a school). 

Note:  Because of Lexan’s flexibility and very high rate of thermal expansion, glazing rebates need to be deeper than provided on standard window or door sections.  

All panels below 1m should be impact resistant, durable & easily maintained. 

The following gives guidance on the suitability of various opening window system types.

Awning sashes are mounted on friction arms for manual operation or small frictionless arms for remote control gear. 

Awning sashes while giving good rain protection, are generally the least suitable window for summer conditions as the limited sash extension possible with their control gear effectively masks their openings.  Further, if located over roofing or paving the sashes can act as a funnel for ducting hot air into the building. 

Awning sashes may be the most practical windows for high level ventilation in exposed locations (e.g. clerestory windows), and if used, every alternate sash should be operable. 

To reduce the potential danger of injuries where opening onto walkways and circulation spaces, awning sashes should only be used above 2100mm. 

Casement sashes are not appropriate for most school applications due to restricted available sizes, limited ventilation potential, lack of suitable control gear and poor durability of components. Casement windows can only be used with DoE Planning Committee approval 

Adjustable louvre windows offer good ventilation potential but are easily vandalised, are generally unsuitable for use with laminated glazing and have poor infiltration and water tightness when compared to other window forms.  Vertical louvres are not to be used when exposed to weather.

Horizontal adjustable glass louvers can only be used with DoE Planning Committee approval.

If approved, glazed operable louvres should preferably be the security type with metal surrounds.  They should be incorporated into the window suite with careful detailing to ensure watertightness. 

They should not be used in exposed situations and should be protected by wide eaves or a covered way. 

If used at low level, the louvre blade width should not project beyond the wall face. 

Refer to DG / DOORS 

Hinged doors are to be to commercial grade standard installed in frames to match the window frame sections. 

Refer to Specification Guide - SG /  DOOR HARDWARE 

Include door stops and/ or hold open devices where doors may be kept open for extended periods.   Generally automatic door stop and holders (auto stops), should be used to prevent damage to the doors, hinges and door closers.

Where doors open externally against a wall surface, the automatic door stop and holders should be fixed to the wall surface at approximately 2m above finished floor level.  Where this is not practicable, provide a steel bollard or railing for fixing the stop with protective hood.

Entry/egress doors in Primary Communal Hall, Secondary Gymnasium and Movement Studio should be fitted with a full length overlapping cover strip at the meeting edges of the door leaves. 

Note: that “Interfold quick-fix” hinges or wide throw hinges to clear reveals are not recommended due to associated maintenance problems.

• Swan Neck System (SSN), is suitable for sashes and louvres 2 to 3m from floor or where fly screens, blinds, security grilles, etc. are to be fitted.
• Torque Rod System (T/R), is suitable for sashes 3 to 5m from the floor in Gymnasiums. The heavier duty torque rod system enables more sashes to be controlled from the one regulator.  Under certain circumstances an increased opening beyond the standard can be achieved.
• Electro-Mechanical System, is the most effective for sashes over 5m from the floor. Either the swan neck or torque rod system is used in conjunction with the electric system.  The use of electric controls enables multiple sashes and louvres to be operated from a central operating point.

Sashes with any dimension exceeding 1200mm should have two (2) points of contact to each sash. 

Generally                                   1350mm from floor

Gymnasium                               1800mm from floor

Detachable handles may be specified.

31.29.01 Fixed Louvres

• Fixed louvres should only be used in areas such as toilet areas and plant rooms, where permanent ventilation is appropriate.
• BCA thermal performance requirements for spaces that are provided with heating or cooling will generally preclude the use of louvres due to their permanent open nature.
• The use of fixed louvers in non habitable spaces (eg toilets) should not compromise the insulation requirements of adjacent habitable spaces.
• In external walls, vulnerable to vandalism, solid louvres should be prefinished steel or aluminium.  Louvre blades should be of robust design with short lengths and/ or reinforced so  as to prevent blades being forced apart.
• Louvres are to have vermin mesh

31.29.02 Fixed Louvres

• Security Stores: fixed louvres are a security/safety risk and should not be used.
• SSP Toilets
  • Some SSP children have difficulty regulating their body temperature
  • These are areas where children may spend some time semi-naked
  • Treat the shower/toilet room as a habitable space for thermal comfort

31.29.03 Operable Louvres

• Louvres should seal once closed to avoid infiltrations and air leakage
• Minimise use on elevations exposed to strong prevailing winds and rain
• In external walls, vulnerable to vandalism, solid louvres should be prefinished steel or aluminium