A buyer's guide to roof windows

Some design and building projects need a window on the roof to let natural light into a room. 

If your customer has asked for a roof window or is considering installing one, you’ll need to know how to choose the right one.

What is a roof window called?

A fixed roof window is also called a skylight. Skylights are installed on the roof of a building to let natural sunlight in. If a roof window moves or opens, it has a different name, depending on how it works. Roof windows come in different shapes and sizes and are used for many reasons. Understanding roof windows and their benefits is important to help you choose the best one for your project.

Roof window types

There are several types of roof windows, all with different features and benefits.
 

Roof window shapes

Roof windows come in many different designs. What shape you pick depends on the architectural style and type of roof.

Some common shapes are:

• rectangular
• square
• round or circular
• polygonal
• doomed or bubble skylights
• pyramid

Manufacturers might not have every roof window shape in all types, so it’s important to check what’s available before starting your project.

What size roof window do I need?

Choosing the size of a roof window depends on several things, such as how the window will be used, the room size, available roof size and what the customer wants. Here are some things to consider when deciding what size roof window you need.

Window use

Think about how the room will be used and why you’re installing the roof window. If you're looking for natural light, you may need a larger window to let more sunlight in. If letting in air is important, you’ll need a size that gives good airflow.

Room size

Look at the size and shape of the room where the roof window will go. A small room may need a larger roof window to make it feel bigger and bring in more light. In larger rooms, more or bigger roof windows may be best to help balance the space and give good light and airflow.

Building regulations

Local building codes and regulations might tell you the minimum or maximum window size. These rules make a building safer and stronger and ensure energy efficiency.

Roof pitch

You’ll need to think about the roof's pitch and how much space there is to install a roof. Steeper roofs may be best for larger windows, while roofs with shallow pitches might need smaller options. Make sure the chosen size fits the roof space and doesn't weaken it.

Design

Consider how the roof window looks with the rest of the roof space and building. The roof window size should fit the roof's scale, creating a lovely look inside and outside.

Manufacturer recommendations

Look at the manufacturer's advice for the roof window. They often give information on the best size based on the product's features and how it will be used.
 

Things to consider when choosing a roof window

There are several things to consider when choosing a roof window design and type for your project.

Purpose

Think about how the window will be used and why it’s needed — this will help you choose a type of roof window and any extra features. For example, a roof window in a bedroom might need built-in blinds, while a bathroom roof window will need to provide good ventilation.

Size

Consider the size of the room and the space on the roof for the window. Larger windows let in more natural light, but you need to ensure they fit the room size and not weaken the roof.

Roof shape

The shape of a roof can determine the type of roof window you choose. Steeper roofs may need special installation methods and may limit the type or size of the roof window. You also need to make sure the roof is strong enough to hold the window’s weight.

Sunlight

Look at the direction of the roof and how much sun it gets. South-facing windows get more direct sunlight than north-facing windows. This can influence the type of roof window glazing or coatings you choose to control heat, glare and UV protection.

Energy efficiency

Look for roof windows with good energy efficiency ratings. Features like double or triple glazing, low-emissivity (Low-E) coatings and insulated frames can help minimise heat loss, improve insulation and use less energy.

Noise reduction

Roof windows with noise-reduction features are good for buildings in busy areas. Choose a window with laminated glass or other sound insulation to make the room quieter and more peaceful. 

Moisture

Choose roof windows with moisture barriers and good ventilation. This will reduce condensation and moisture-related issues in a room. 

Security

Make sure the roof window follows all safety rules. Look for features such as tempered or laminated glass, locks and child safety protection, especially for windows that can be easily reached.

Brand and warranty

Research well-known brands that sell quality products and have good customer reviews. Check the manufacturer’s warranty to make sure the roof window has coverage and support if there are any issues.

Key takeaways

Choosing a roof window is an important decision that can change how a building looks, works and feels. 

With the right roof window, you can bring in natural light, improve ventilation and enjoy beautiful views of the sky and surroundings.

Make sure to think about your project needs and consider all the options to make a good decision. Your roof window choice will create a bright, airy and welcoming space that will be enjoyed for years to come.