Stage 2

Roof Window Planning​

22 Slides

• The Construction of the Building
• User Requirements
• Building Regulations
• Building Orientation

Roof Window Planning

The Construction of the Building

The Construction of the Building

Identifying the most suitable Keylite roof window for any building as well as the end user must consider the following construction aspects:

• Distance between rafters
• Roof pitch of the building
• Building regulations
• The roofing material used

The Construction of the Building

Rafter Distance

The dimensions of the roof window will often be predetermined by the distance between the rafters. It is essential to check whether the positioning as well as the size of the roof window chosen doesn’t require cutting of the trimmers as this may not always be possible. 

The Construction of the Building

Roof Pitch

Consideration of the roof pitch when choosing a Keylite roof window may restrict an end user on the system they desire. Across Keylite’s product range we can accommodate for roof pitches between 0-90º. However not all applications are designed to suit this entire range.

The Construction of the Building

0-5° Examples

Roof Lanterns

Flat Roof Apex Systems

The Construction of the Building

0-15° Examples

Flat Roof Systems

Combi Flat Roof Systems

The Construction of the Building

0-25° Examples

Flat Roof Domes

Flat Glass Rooflights

The Construction of the Building

Building Regulations

There are numerous building regulations to consider when selecting your Keylite roof window.

From recognition of conservation areas to ensuring Fire Escape applications are fit for purpose, our product range can be tailored to comply with building regulations where required.

The Construction of the Building

Roofing Material

The appropriate flashing kit must be supplied with every Keylite roof window.

The type of flashing required will be determined by the roofing finish to ensure a watertight installation every time.

User Requirements

User Requirements

Environment

A Keylite roof window may be required in a room with frequent high levels of humidity.

In these instances, a polyurethane window is naturally the most sensible choice.

Circumstances where a roof window is situated out reach may also require an electrically operating kit to increase the ease of use.

User Requirements

Window View

To allow a clear view for an end user through a reachable roof window it is important to note the optimum window height relies on the roof pitch.

The greater the pitch, the greater height of roof window is required for a clear view when standing or seated.

User Requirements

Obstructions

The most effective standing position to operate a Keylite will depend on the function of the window. Centre-pivot roof windows allow furniture to be placed directly beneath it without causing any obstruction.

Top Hung/ Fire Escape roof windows maximise the living space as these units must be easily accessible to not only successfully operate the window but to ensure an easy escape if necessary.

Alternatively, out of reach windows fitted with Keylite electric kits make it possible to operate a centre-pivot window from anywhere in the room, guaranteeing an obstruction free solution.

Building Regulations

Building Regulations

Means of Escape

If building regulations state the roof window installed must facilitate emergency exit purposes the window cannot have an obstructed access route nor can the opening exceed 450mm in height and must be at least 0.33m².

Building Regulations

Height Requirements

The minimum sill height requirement for an operable window must be positioned at least 0.8m above floor level.

Restrictor locks can be provided as an additional safety feature for centre-pivot windows at such an easily accessible height.

Daylight Requirements

To ensure sufficient levels of natural daylight into the living space the standard recommended roof window is to be at least 15% of the floor area.

Scottish regulations state a room’s total glazed area must aggregate to 1/15th of the entire floor space.

Building Regulations

Ventilation

For our health as well as home maintenance purposes, ventilation of a building is essential. Building regulations state the volume of necessary ventilation depends on the size and use of a specific room. Additional extraction devices are required in kitchens and bathrooms to efficiently control large volumes of vapour.

Safety

For windows situated less than 0.8m from floor level, building regulations state that safety glazing units are to be installed. It is also recommended that highly positioned roof windows contain laminated glazing which will prevent the glass from falling should it experience any damage or breakages

Building Regulations

Thermal Efficiency

Keylite’s innovative design combined with our highly efficient thermal glazing units allow our roof windows to comply with current building regulations.

The expandable thermal collar and glazing options which can achieve U-Values as low as 0.6 W/m²K ensure optimum insulation performance.

Conservation

If a property is based within a conservation area this will affect the type of roof window which can be installed. Conservation Keylite’s are supplied with a black exterior finish to comply with the preservation of architectural and/or historical interest regulations. Always check with the local building authority to ensure the system is suitable for the area.

Installation Conditions

Installation Conditions

Building Orientation

Maximising the amount of natural daylight which enters a building can reduce utility bills through increasing both light and heat levels radiated into the property. Ensuring your roof windows are installed in a south-facing position is the most effective application to increase this cost saving solution.

Quiz

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