WINDOWS

An opening made in a wall for the purpose of providing daylight, vision and
ventilation.
Construction of windows is similar to that of doors consisting of a frame and a
shutter. The frame consists of two vertical members known as jambs, one
horizontal member connecting the jambs at the top known as a head, and
another at the bottom known as a sill. The shutter can be glazed, panelled or a
combination of both.
Functions of windows
 To provide daylight into the room or building
 To admit air into the building or room
 To provide a view of the exterior
 Improve the appearance of the building
 Prevent or exclude excessive wind and rain from entering the room or
building
 Prevent excessive transfer of heat, sound and fire
Functional requirements of a window
 Durability and freedom of maintenance
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  Aesthetics
 Security and safety
 Resistance to passage of sound
 Resistance to passage of heat
 Provision of ventilation
 Fire safety
 Strength, stability and air-tightness
Factors determining the choice and size of a window
 Size of the room
 Location of the room
 Utility or function of the room
 Direction and speed of wind
 Climatic condition at the site e.g. humidity and temperature variation
 Architectural treatment to be given to the building.
 Cost of the window visa vie the budget
 Required level of privacy.
 Amount of light required

Technical terms

Sash – part of the window that holds the glass OR the framework around the
glass to keep it in place. OR the moveable part of the window made of
vertical and horizontal framing members that hold the glass.
Pane – sheet of glass inserted in the frame of a window.

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Casements – a window that is attached to its frame by one or more hinges at
the side. They ae used in pairs or singly within a common frame in which
case they are hinged to the outside.
Mullion – vertical member that forms a division between two units of a window
or screen OR vertical member between casements or panes of a window
or the panels of a screen.
Transom – horizontal beam that is paired with a mullion or jambs and divides
a window’s upper parts into additional lights
Sill – horizontal surface o structure at the bottom of a window.
Grilles/Muntins/sash bars/glazing bars – parts of a window that divide the
glass into four or more sections. Not all windows have grilles. The bars
are decorative and make windows appear as multiple panels. They can
be installed in between or on top of the glass
Window screen – a standard feature for most windows today. It is custom-made
from plastic, fiberglass, or wire to fit the window opening. When a
window is open, screens keep insects, bugs, and dust from entering the
house

Vent light - An opening part at the top or bottom of a window, hinged at either
its top or bottom rail so that it may be swung open to provide ventilation
without opening the entire sash.
Fixed light - The glazed part of the window that is not hinged or opening i.e. it
is fixed in position.
Fanlight – semi-circular or semi-elliptical shaped window with glazing bars
radiating out like an open fan. It is usually placed over another window
or doorway and is sometimes fixed to a transom. The bars in the fixed
glaze spread out in the manner of a sunburst.
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Rails - Rails are the horizontal window components of a sash.
Architrave – a decorative molding that frames the wall around the window.
Placing an architrave around your windows improves their visual appeal.
Architraves come in both pattern and minimalist designs.

Considerations for window design

 The size and number of windows should be sufficient to provide adequate

light and ventilation in the room.
 Whenever possible, windows should be located opposite each other.
North side windows permit more daylight without glare.
 External windows shutters should open to the outside and vice versa
 External windows should be provided with mild steel burglar proofing
 Buildings in humid regions need special attachments for adequate
ventilation.
 Etc.

Classification of windows

These may be classified in a number of ways or a combination of a number of

ways

1. Method of opening

a) Hinged e.g. side hung casement, top hung sash, bottom hung sash
etc.
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 b) Pivoted e.g. horizontally pivoted, vertically pivoted and louvered.
c) Sliding composite e.g. vertically sliding and horizontally sliding.
d) Composite e.g. projected side hung, projected top hung, sliding folding
door and tilt and turn etc.

2. The materials from which they are made e.g. steel, timber, aluminium,
uPVC, glass etc.
3. Size of the windows e.g. big or small
4. Shape of the window e.g. Rectangular, Circular, Triangular, Bay, Bow
etc.

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 5. Position of the building e.g. Dormer window, Corner window, Transom
window, Vent light, Sky light etc.

Fixed window/Picture window

The glass pane or the glazed shutter is permanently fixed in the wall opening.
Used in structures where light or vision alone is required since no ventilation is
possible through fixed windows.

Pivoted window

Here, the shutter is capable of rotating about a pivot fixed to the window frame.
The shutter can either vertically or horizontally.

Sliding windows

In this type of window, the shutters move on a roller bearing and can slide
either horizontally or vertically. The movement of shutters is done by the
provision of roller bearings. Generally, this type of window is provided in buses,
bank counters, shops, etc.

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Single and double hung windows

A type of window that is opened and closed by sliding vertical sashes up and
down.

A single hung window, the bottom sash moves up and down to open and closes
the window respectively while the upper sash is fixed or remains stationery.

In a double hung window, both the lower sash and upper sash move up and
down respectively and may tilt out for easy cleaning.

Casement windows

A casement window opens and closes like swinging an open door. It utilizes a
hinge on the side and generally incorporates a cranking mechanism to
open/close and a lever lock to seal the window shut.

Louvered/Jalousie/venetiated window

Unique style of pivoted window that splits into different slats of metal or glass.
The window opens like a set of blinds, simply crank the lever and the slats
which creates a series of gaps for air flow and light.
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Bay window

This is a window projecting outwards from the walls of a room. It provides an

increased area of opening for admitting light and ventilation and provides more
space in the room as it projects outside. It usually consists of a centre window
from which two side windows are angled.

Bow window

Similar to a bay window but its structure is curved, creating a rounded

appearance on the outside of the home and the windows are equal in width.

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Corner window

This is located in the corner of a room. This window admits light and
ventilation from two directions at right angles. They improve the aesthetic
appearance of the room.

Dormer window

Vertical window built on the sloping side of a pitched roof to provide light and
ventilation in the space enclosed below the roof and above the ceiling a.k.a
attic.

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Gable windows

Windows provided in the gable end of a pitched roof.

Clerestory windows

Clerestory windows are often narrow windows installed at or above the roofline
in an interior living space. The shutters are able to swing with the help of cord
over pulleys. These also enhances the beauty of building.

Skylight

Fixed windows provided on the sloping surface of the roof being parallel to the
sloping surface of the roof. It is added to provide more natural light into the
room or building where you have limited options with the exterior walls.

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Lantern windows

Lantern windows are provided over the flat roofs. The main purpose of this
window is to provide the more light and air circulation to the interior rooms.
Generally, they are projected from the roof surface so, we can close the roof
surface when we required

Metallic windows

Wooden and metallic windows are two of the most commonly used windows.
Metallic windows are made using bronze, steel, galvanised mild steel, stainless
steel etc.

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Advantages of metallic windows

- Stronger and more durable compared to wooden windows

- Not subject to expansion and contraction as a result of weather changes
- Rot proof and free from hazards like termites and fungai
- They are highly fire resistant
- Present elegant appearance due to great precision and quality control in
fabrication
- Provide more area for light and ventilation than wooden windows since
they are made of thin sections

Disadvantages of metallic windows

- Some metals are expensive

- Some metals are affected by corrosion and rusting
- Conduct heat making rooms hotter
- Some metals interfere with wireless signals
- High quality metals can be costly
- Metal windows may have limited design and style options.
Wooden windows
Wooden windows are timeless, durable and boast excellent technical
features

Advantages of wooden windows

- Add warmth and character to a building.
- reduces heat transfer in the building since wood is an insulator.
- Properly maintained wooden windows can last decades.
- Wood absorbs sound, reducing external noise.
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 Disadvantages:
- Wood can rot, warp, or crack with excessive moisture.
- Wood is susceptible to insect and rodent damage.
- Untreated wood can deteriorate quickly.
- High-quality wooden windows can be costly.

Other types of windows

 Egress windows
 Transom windows
 Glass block windows
 Storm windows
 Hoppers
 Awning/top hung windows

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