How many windows do I need for my house extension?

Have you been planning a house extension? Wondering how you can maximize natural light in the new room? Not sure whether you need to go with roof lights, casement windows, or skylights?

There are many different types of windows, many potential locations to place them, and many sizes, aesthetics, and blinds. Choosing the right number and type of windows is often difficult and confusing.

This article is your ultimate guide to choosing windows for a house extension. From why windows are important to the factors that you should consider, we’ll go over everything!

Why does the number of windows matter?

#1 It Impacts the aesthetics of the extension and the house

The impact of windows on a property’s aesthetics has been known and studied since ancient times. The windows aren’t only a look from inside the space into the outdoors, impacting how furniture is perceived, which elements of the room are in focus, and how light and colours interplay, but the number and placement of windows also impact the extension and the house’s curb appeal, influencing how it is perceived from the outdoors.

#2 It Influences natural lighting and ventilation

There’s no overstating how important ventilation and natural light are for extensions. Ample natural lighting and fresh air make a space healthier, warmer, and more welcoming. Interior designers and homeowners should put a lot of thought into how the new space influences air circulation and natural lighting.

The number of windows, the type of windows, and the location of windows will all directly impact how much air and light the space gets. Most extensions will need at least one or two windows, often more.

#3 Insulation and energy efficiency are also factors

The quality of the windows, the number of panes, and how air-tight the frames all influence the property’s insulation and energy efficiency. A poor, thin window in a cold climate will make the space colder and more uncomfortable in the winter and increase energy bills. If you want to keep costs down, you need to choose the right windows for your building extension.

#4 It Determines the property’s value 

What makes up the value of a property? Its aesthetics, practicality, energy efficiency, and curb appeal. As we showed above, the windows impact all these aspects of the building, so naturally, they also impact the property’s value as well.

From needing planning permission to construction work, extensions cost a lot of money but by adopting desirable designs and judiciously placing windows, you’ll not only have a comfortable new space but can even get a decent return on investment (ROI) due to the increase in the value of your property.

5 Factors determining the right number of windows for your extension

#1 Type of extension

There are many types of extensions. Are you considering a flat roof extension? Do you need a kitchen extension? Or perhaps you are thinking about creating an extra room with a dormer extension?

Each of these types of extensions needs a different number and type of windows. For a kitchen extension, air circulation is vital, so larger windows are preferable. For dormer extensions, a roof window is an excellent choice.

Think about the type of extension and the type of room you are trying to create and then choose your new windows based on that information!

#2 Size of roof window extension

The size of the room will determine how much natural light and air circulation is needed. Smaller rooms can function perfectly well with fewer windows. A single flat roof skylight is often enough to provide sufficient lighting to the room. Remember: There’s no one-size-fits-all solution.

#3 Design and approach to the extension

The design and aesthetics of the house are important factors when choosing the windows. Sash windows are popular with period homes and traditional aesthetics while dormer windows give a roof a modern look. Carefully consider how the windows, their size, and their number will reflect on the property’s design before making a final decision.

#4 Budget

How much money are you willing to spend on windows and blinds? Construction work is, by its very nature, expensive. From labour costs to planning permission, budget overruns are very common.

Will you go for a more affordable flat sash window or a more embellished skylight? Carefully consider how much money you can spend on the property renovation and plan accordingly.

#5 Household needs and individual preferences

The number and size of windows will ultimately impact the atmosphere inside the room, the amount of direct sunlight, and air circulation, and preferences for these elements change from one person to another.

If you love sunlight, it might be worth getting planning permission to install a skylight for your flat roof. On the other hand, if you dislike direct sunlight, fewer or North-facing windows are the answer!