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Dormer roof sliding windows and juliet balcony for loft conversion

Loft conversion windows: what works best?

12 March 2024
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Loft conversion windows: your choices

Going up into your loft makes sense, of course. A loft conversion adds extra living space without losing any valuable garden, but whether it’s destined to be a guest bedroom, teenager’s pad or home office, you’ll appreciate glazing that maximises the daylight, adds new perspectives and preserves your privacy.

Rooflights for loft conversions

The cheapest way to bring daylight to a converted loft space is to install rooflights which follow the existing roofline. Rooflights can be installed under Permitted Development to provide additional natural light into loft extensions as long as they don’t extend beyond the existing roof plane.

External view of fixed rooflight for converted roof space

You’ll need 2.25m of head height in the middle of your room and you may require planning permission if the roof windows are at the front of your house. Rooflights come in standard sizes, but it’s really worth have a conversation about bespoke rooflight dimensions to bring strong design and a wealth of light to your new room. Of course, our surveyors will calculate the optimum glazing to ensure your new space is comfortable all year round.

Choose rooflights with slimline frames and the highest U-values for an energy efficient, contemporary look. Aim for windows that glaze 20% of roof space either by a series of evenly spaced windows or one large window. We recommend opening rooflights are fitted with automated rain sensor controls – to avoid them being left open accidentally.

See how fixed rooflights in a sloping roof have maximised the views and light in this country house. It’s a design that could transfer very effectively to a loft conversion.

Rooflights for upper floor glazing suitable for loft conversions

Sliding glass doors and Juliet balconies for loft conversions

Our smaller SL220 sliding doors have to be our favourite glazing solution for structural loft conversions with dormer and gable end windows.

Dormer windows are one of the most popular types of windows seen in loft conversions and loft extensions. The dormer itself extends out of the original roof of the property, giving you additional headspace and usable floor space – great for lofts with low or sloping ceilings.

Gable end windows on detached or end of terrace properties open the entire side of the property up to the roof ridge to flood a loft conversion with natural light and offer the best of any views.

Suitable for both large dormer and gable end openings, slimline sliding doors with a Juliet balcony deliver floor to ceiling glazing to maximise views, light and create a real wow factor. The frameless Juliet balcony forms an almost invisible glass balustrade allowing you open the doors to the outside in total safety.

In this loft conversion, the dormer window, complete with sliding system and Juliet balcony, creates a superb master bedroom.

Dormer loft conversion with sliding doors for windows

And below, the rear facade of this 1930s semi-detached home has been completely transformed. The loft conversion now has a bespoke fixed window, sliding doors and Juliet balcony to create a master bedroom offering fantastic views across the city.


Loft conversion windows including Sliding door with glass balustrade

Box windows for loft conversions

If your project involves replacing or raising the entire roof, you’ll enjoy the maximum available space for a loft conversion. Creating a mansard roof (in effect an additional level to your house) creates opportunities for extensive and exciting glazing combinations. Box windows or oriel windows with their frameless window seat design extend your space and creates new views and interesting perspectives.

This London apartment loft conversion is an example of how ‘going up’ delivers transforming panoramic views in all directions from its sliding glass walls, terraces secured by glass balustrades and bedrooms with rooflights and stunning glass box windows.

bespoke aluminium oriel window for loft conversion

Walk on rooflights for roof terrace

Walk on flat glass is an exciting option for preserving light levels on lower floors if you are planning to convert and expand a loft space. Walk on rooflights can be installed within a floor or outside as part of a terrace or balcony. Choose an opaque walk-on rooflight to ensure valuable light filters into the floor below.

Opaque rooflights on roof terrace

Fixed windows for loft conversions

New access staircases to an upper loft level can be lit with long picture windows to preserve the light, open and airy feel at the top of the house. Internall glass balustrading can also increase the light levels in upper storeys.

ODC aluminium floor to ceiling sliding door system and fixed window installed in London


ODC designs and manufactures bespoke aluminium rooflights, glass doors and windows with superb thermal efficiency for loft conversions.
Read more about our rooflights and window products, or give us a call. We’d love to hear about your project and have a huge wealth of expertise and experience to share with you.