Thinking about the best windows for a loft conversion? There are lots of different options available – make sure you pick the right ones for your property with our guide.
You can also view our complete guides to loft room conversions and loft ventilation.
Loft conversion window options
When planning a loft conversion, selecting the right windows is important not only for aesthetics but also for functionality. Windows can improve the overall value and comfort of your loft space, and here we’ll explore various types that fit perfectly into loft conversions.
Ordinary windows
Ordinary windows are a good option for loft conversions. They come in various styles such as sash, casement, and tilt-and-turn, each providing unique benefits. Casement windows, for example, are ideal for promoting good ventilation, an essential aspect in a newly converted loft. When integrating windows for loft conversion, consider the orientation and size to maximise natural light and airflow, keeping your loft bright and airy.
Learn when to replace windows and why natural light is beneficial in our expert guides.
Roof windows
Roof windows are an excellent choice for loft conversions due to their ability to fit seamlessly into the roofline. Roof windows offer plenty of light without compromising privacy. These are a common choice for loft conversion windows. Opting for high-quality, durable materials ensures longevity and better insulation, which is vital for energy efficiency.
Our Triple Glazed Rooflight is a great choice
A high-performance, UV-protected triple-glazed rooflight with a self-cleaning glass coating that breaks down dirt, so rainwater can wash it away, keeping glazing clearer with less maintenance.
Price: Approx. £299.00 ex. VAT (size dependent).
Specs:
- Triple-glazed, UV-protected glass for superior insulation and comfort.
- Self-cleaning glass reduces manual upkeep.
- Available in multiple sizes (commonly 600 × 600 mm up to 1000 × 3000 mm).
Warranty: Covered by a 20-year manufacturer warranty standard on this product.
Roof lanterns
Roof lanterns make a striking addition to your loft conversion. They sit above the roof and provide a glazed structure that allows light in from all angles, making them great for spaces with limited natural light. Apart from their aesthetic appeal, roof lanterns can improve thermal efficiency, making your loft space usable throughout the year. They are often considered for larger loft conversions where aesthetics and architectural impact are priorities.
Try our Korniche Roof Lantern
Price: From approx. £594.73 (depending on size and options).
Specs:
- Thermally broken aluminium frame for improved insulation.
- High-performance glazing with options to achieve U-values around 1.0–1.2 W/m²K.
- Slim sightlines and minimalist design maximise glass area.
- Available in a range of sizes and finishes to suit different loft layouts.
Warranty: Typically covered by a 10-year manufacturer warranty on the lantern structure and glass performance (standard for Korniche products).
Flat rooflights
Flat rooflights are an effective option for introducing more light into your loft conversion, especially in areas with limited vertical space. These installations are flush with the roof, offering a sleek and modern look without protruding into the skyline. Ideal for flat-roofed lofts, they provide plenty of daylight and can significantly reduce the need for artificial lighting, making them an energy-efficient choice for your home.
Learn when to replace skylights in our guide.
Our Flat Rooflight is our most popular product
Price: From approx. £259 – £2,800 ex. VAT depending on size, glazing (double or triple) and optional extras such as solar control or self-clean coatings.
Specs:
- Bespoke sizes: Custom options cover a wide range of glass dimensions to suit your project (e.g., 600 × 600 mm up to 3000 × 1000 mm and beyond).
- Glazing options: Double or triple-glazed units available for enhanced thermal performance; argon gas fill helps reduce heat loss and improve insulation.
- Design: Low-profile flat roof appearance that blends into modern and contemporary buildings.
Warranty: Supplied with a manufacturer’s warranty on the glazed units; installation-specific warranties and performance guarantees depend on the exact configuration and installer. (Standard practice for these bespoke products; see supplier terms.)
Pitched rooflights
For those with pitched roofs, pitched rooflights are tailor-made to complement the angle of your roof. These windows not only add to the architectural lines of your loft but also increase the amount of natural light entering the space. Pitched roof lights can be designed to be non-opening or have the functionality to open, providing both light and ventilation via your loft conversion windows.
Try our RoofLITE+ Pitched Roof Window
Price: From approx. £194.57 to £736.82 excl. VAT depending on size and configuration (e.g., different glazing and finish options).
Specs:
- Multiple size options, typically from 55 × 78 cm up to 114 × 118 cm.
- Centre-pivot opening for easy ventilation and cleaning.
- Choice of finishes including moisture-resistant PVC, white paint or natural pine.
- Compatible with flashing kits for tiled or slate roofs (sold separately).
Warranty: Supplied with a 10-year manufacturer’s warranty when installed with the official RoofLITE flashing kit for long-term confidence.
Opening rooflights
Opening rooflights offer both light and ventilation, making them an excellent choice for maintaining air quality and comfort in your loft space. These windows can be operated manually or via electronic systems, allowing for ease of use. They are perfect for loft conversions where better air circulation and ventilation is needed.
Our Electric & Manual Opening Rooflights are a great choice
Opening rooflights from Toughened Glass Systems that flood loft spaces with natural light and provide ventilation when opened. You can choose manual opening with a pole or electric opening with wall switch, remote or rain sensors, ideal for letting fresh air in and controlling airflow without climbing up to the roof.
Price: Typically ranges from £575 – £2,534 ex. VAT depending on size, glazing, and whether you choose electric or manual opening.
Key Specs:
- Sizes: Multiple sizes available (e.g., 600 × 600 up to 1500 × 1000 mm).
- Glass: Laminated safety glass bottom pane plus thermally efficient sealed unit with argon fill and low-E coating.
- Thermal performance: Approx. U-value ~1.1 W/m²K for excellent insulation.
- Frame: Powder-coated aluminium frame (standard anthracite RAL 7016) with slim sightlines and flush fit.
- Operation: Choose manual with pole or electric with switch/remote/rain sensor.
- Warranty: Rooflights are guaranteed for 10 years for structural performance, with 5-year insulated glass warranty and a 1-year warranty on electric actuators where applicable.
Juliet balconies
Juliet balconies are a great choice for loft conversion windows, adding not just aesthetic value but also a sense of openness. These installations involve a vertical sliding or French door set behind a safety railing, without an external platform. They allow for unobstructed views and the enjoyment of the outdoor environment from the comfort of your loft, making them popular in urban areas where outdoor space is at a premium.
View our Glass Juliet Balconies
Custom-made toughened and laminated glass Juliet balcony designed to sit across an upper-floor opening, creating a modern balustrade that lets in natural light and maximises views without extending outwards. Toughened glass conforms to British safety standards for protective barriers and can be supplied in clear or low-iron finishes, with self-cleaning glass and chrome or stainless fixings available to suit your style.
Price: From around £293 – £700 ex. VAT depending on size, thickness and fixings chosen.
Specs:
- Laminated toughened glass panels (typically 13.5 mm, 17.5 mm or 21.5 mm thickness available).
- Chrome or stainless-steel fixings (4 or 6 fixings depending on size).
- Options for clear, opti-white, frosted or tinted glass.
- Custom sizes supplied to order.
Warranty & Delivery: Toughened Glass Systems products are made to order and delivered UK wide; while specific warranties vary by product, glass balconies typically include manufacturer quality assurances and conform to UK safety standards.
Loft conversion window comparison guide
|
Window Type |
Best for |
Light Levels |
Ventilation |
Typical Price |
Key benefits |
Warranty |
|
Ordinary windows (casement, sash, tilt & turn) |
Dormer lofts, vertical walls |
Medium–High |
Yes |
Varies by style & size |
Familiar look, good airflow, flexible styles |
Varies by manufacturer |
|
Roof windows / fixed rooflights (triple-glazed self-clean) |
Sloped roofs, privacy-sensitive lofts |
High |
No |
From ~£299 |
Excellent thermal performance, low maintenance, strong daylight |
20-year manufacturer warranty |
|
Roof lanterns (e.g. Korniche) |
Larger loft conversions, feature spaces |
Very high |
No |
From ~£594.73 |
Light from multiple angles, strong architectural impact |
10-year manufacturer warranty |
|
Flat rooflights |
Flat-roofed lofts, modern designs |
High |
No |
~£259 – £2,800 |
Flush, minimalist design, bespoke sizing |
Manufacturer warranty (spec dependent) |
|
Pitched rooflights (RoofLITE) |
Traditional pitched roofs |
High |
Yes (centre-pivot) |
~£194.57 – £736.82 |
Cost-effective, ventilation included, easy cleaning |
10-year manufacturer warranty |
|
Opening rooflights (manual or electric) |
Lofts needing airflow & light |
High |
Yes |
~£575 – £2,534 |
Combines daylight with controlled ventilation |
10-year rooflight / 1-year electric |
|
Juliet balconies (glass) |
Loft bedrooms, urban homes |
Very high |
Via doors |
~£293 – £700 |
Maximum light, views, no external footprint |
Manufacturer quality assurance |
Factors to consider
Maximising natural light
Maximising natural light should be a primary goal when selecting windows for your loft conversion. Natural light not only makes the space feel larger and more inviting but also helps reduce energy costs. Consider the placement and size of the windows, aiming for those that offer natural light without compromising on thermal efficiency. Roof windows and large glazed units are particularly effective in achieving these goals.
Preventing overheating
While it’s important to maximise natural light, it’s equally important to consider the heat of your windows to prevent your loft from overheating. High-quality glazing solutions that include solar control coatings can help manage heat gain during warmer months. Ventilation is also important. If your home gets hot regularly in summer months, it may be worth getting a loft conversion window that can open and close.
Learn how to make a room cooler in our guide.
The number of rooms in your loft conversion
The number of rooms in your loft conversion will influence your window choices. Bedrooms may need windows that offer good sound insulation, light control and privacy. Living areas might benefit from larger, more expansive glazing to enhance views and natural light. Carefully plan each room’s windows to align with these functional needs.
Whether your loft conversion has a bathroom
If your loft conversion includes a bathroom, consider privacy and ventilation in your window choice. Frosted or obscured glass can provide privacy, while opening windows or rooflights can offer ventilation to prevent moisture build-up and maintain air quality. These features are essential in maintaining the structural integrity and comfort of bathroom spaces in loft conversions.
Learn what to do when there’s mould in your loft.
The views
Choosing the right windows can dramatically improve the views from your loft conversion. Consider the orientation of your home and the natural landscapes available when selecting window placements. Expansive windows or strategically placed rooflights can frame beautiful outdoor scenes, making your loft a more pleasant and valuable space.
Security
Security is another concern in any home improvement project, including loft conversion windows. Any loft conversion windows installed should be robust and secure. Opt for windows that come with strong locking mechanisms and are made from toughened or laminated glass. These materials are harder to break, offering an added layer of security against potential break-ins.
Temperature
Managing the temperature within your loft conversion is important for year-round comfort. Select windows with good insulating properties to help maintain a consistent indoor climate. Double or triple-glazed windows can significantly reduce heat loss in winter and keep your loft cooler in summer. Additionally, consider windows with thermal breaks and inert gas fillings, which are excellent for reducing thermal transfer and improving energy efficiency.
How to maximise light in a loft conversion
Getting the light right can make or break a loft conversion. Because these spaces sit right at the top of the house, they depend far more on roof and elevation glazing to feel open and comfortable. Without it, loft rooms can easily feel closed in.
One of the simplest ways to bring in more daylight is to get light in from more than one angle. Rooflights are great for this, as they introduce strong light from above and help brighten the centre of the room, even when wall space is limited. When positioned well, they can keep a loft feeling light for most of the day.
Adding a Juliet balcony alongside a rooflight can take things a step further. The rooflight provides consistent overhead light, while the Juliet balcony lets daylight in at eye level, which instantly makes the space feel larger and more connected to the outside.
Do loft conversion roof windows require planning permission?
Whether you need planning permission for loft conversion windows largely depends on the extent of the modifications and local regulations. Generally, roof windows and skylights often fall under permitted development rights. This means they don’t require planning permission if they do not protrude more than 15 centimetres beyond the plane of the roof, and are not installed in the front of the house. However, we recommend consulting with your local planning authority to ensure compliance, especially if your property is listed or located in a conservation area.
Choosing Windows and Skylights Based on Loft Orientation
Which way your loft faces has a big impact on how your windows or skylights will perform, but it’s something that often gets overlooked. Thinking about orientation early on helps you get the right balance of light and comfort throughout the year.
South-facing lofts usually get plenty of direct sunlight, especially during the middle of the day. In these spaces, it’s often worth choosing glazing with solar control coatings. This helps cut down glare and excess heat while still letting lots of daylight in, so the room stays bright without becoming too warm in summer.
North-facing lofts receive softer, more consistent light, but usually less of it. To avoid the space feeling dull or flat, higher light-transmission glass can make a real difference, helping to pull as much natural light in as possible, particularly during the darker months.
Why choose Toughened Glass Systems for your loft conversion windows?
We offer a range of loft conversion windows that are high quality and reinforced with toughened glass. This means they will last longer, provide better insulation, and offer more security than that of regular glass. Our collection of rooflights include:
More helpful articles:
- Rooflight Loft Conversion Guide
- Why Is Roof Ventilation Important?
- A Guide to Single Storey Extensions
- How to Add Value to Your Home
- How to Know When to Replace Your Windows
- Flat Roof vs Pitched Roof Skylight Extensions
- Types of Roof Vents
FAQs
What are the rules for windows in a loft conversion?
For loft conversion windows, make sure you stick to building regulations regarding safety, ventilation, and energy efficiency. Always verify local planning permissions, especially in conservation areas.
What are the best windows for loft conversions?
The best windows for loft conversions are typically roof lights and skylights. These maximise natural light and improve ventilation. Features to consider include thermal insulation, noise reduction, and user-friendly opening mechanisms.
Do loft conversions need escape windows?
Yes, loft conversion windows require escape windows to comply with safety regulations. These windows must be accessible and large enough to serve as a means of egress during emergencies, meeting the minimum size requirements specified by local building codes.