Oriel Windows Buying Guide: Costs, Planning Permission & Benefits (UK 2025)

Oriel windows are one of the most striking architectural features you can add to a home. Designed to project from the wall without touching the ground, they instantly transform flat elevations into sculptural, light-filled spaces. Whether designed into a new extension or as a modern interpretation of a traditional bay, oriel windows combine practicality, luxury, and design impact.

It is glass technology and development over the years that have made Oriel windows even more popular.  Structural Glass is the key component of modern oriel windows giving them their lovely shape with safety, security, strength and internal comfort.

What Is an Oriel Window?

An oriel window is a projecting glazed box or bay that extends outward from a building’s wall but does not reach the ground. Supported by cantilevered brackets, structural steel, or hidden framing, the design creates a “floating” effect — visually dramatic from outside and beautifully light from within.

Traditionally, oriel windows were used in historic buildings to provide extra space and outlook on upper floors. Modern versions reinterpret the idea using large panes of structural glazing, slim aluminium framing, and frameless corner details.  Now Oriel windows are used on any floor and especially where there may be little light in a particular area of the property.

Today, oriel windows appear in:

• Modern extensions and new builds

• Upper floors of houses or apartments

• Stairwells, home offices, and feature walls

• Commercial or mixed-use buildings

At Glideline, we design and manufacture bespoke aluminium and structural glass oriel windows that combine architectural precision with performance and durability.

Key Benefits of Oriel Windows

1. Extra Internal Space

A projecting oriel creates valuable additional floor area . As mentioned, they are widely used as built in seating often with storage beneath. You can also create oriel windows as a reading nook, or compact workspace. Even a modest projection of 600mm can make a small room feel more open and usable.

2. More Natural Light

Because oriel windows are glazed on multiple sides, they bring in more daylight than a flat window. Light enters from several angles throughout the day, improving interior brightness and reducing the need for artificial lighting.  Additionally in autumn and winter months, they delay the need for artificial lighting.

3. Architectural Impact

Oriel windows instantly elevate the appearance of any home. From the outside, they add depth and dimension to otherwise plain elevation.  Inside, they become a focal point and very soon a favourite space. 

Glideline oriel windows often feature frameless corners, structural glass, and thinsysten aluminium trims for a refined, contemporary look.

4. Enhanced Views

With three or more glazed sides, oriel windows offer panoramic views compared with traditional flat windows. When used on upper floors, they provide clear sightlines over gardens or surrounding landscapes.

5. Property Value and Design Appeal

Architecturally designed homes stand out on the property market. Adding an oriel window can increase desirability and resale value, particularly when incorporated into a well-considered extension or new build.

6. Customisable Design 

There is no off-the-shelf oriel window system.  Each one is bespoke and must be designed around the structure.  When we manufacture your bespoke Oriel Windows, each products gives us full control over:

• Frame colour and internal finish

·       Size and projection depth

• Glazing specification

• Seat or cill detail

• Shading, privacy glass, solar control glass or enhanced security.

7. Compatible with Modern or Period Homes

Although often associated with contemporary architecture, oriel windows can complement period or heritage properties when designed sympathetically. The concept dates back centuries and oriel windows are not a new invention. Instead, modern aluminium creates a more refined version using thermally insulated aluminium and the highest performance safety glass.

How Much Do Oriel Windows Cost?

The cost of an oriel window depends on its size, materials, glazing type, and structural support requirements.

Typical price ranges (supply only):

Installation costs depend on complexity. Because most oriel windows require a steel or aluminium support frame and specialist fitting, expect professional installation to add a minimum of 50%  to the supply cost,  and also depending how much work is required at the property.   These are guide prices only.  Buying power, profit margins, installation costs and warranty support all varies as well as regional price variations.

Other factors affecting price include:

• Structural steel and bracket design

• Access equipment or craning

• Solar control or specialist glass

• Frameless corner detailing, full structural or slimline corner

• Internal finishes such as timber seat boards or plaster reveals

While not a budget option, oriel windows deliver exceptional design value, creating an architectural centrepiece that often defines the entire project. 

Do I Need Planning Permission for an Oriel Window?

In many cases, small oriel windows fall under Permitted Development Rights, but not always. Planning requirements depend on projection depth, location, and property type.

General guidelines:

• If the projection is under 150mm from the wall face, planning permission is usually not required.

• Larger projections, especially on the front elevation or within 2m of a boundary, often do require approval.

• In conservation areas, listed buildings, or flats, planning permission is almost always necessary. 

Your oriel window must also meet Building Regulations, including:

• Part A: Structural integrity and load-bearing support

• Part L: Thermal performance

• Part K: Safety glass and protection against falling

• Part B: Fire safety (especially near boundaries)

At Glideline, we work closely with architects and builders to ensure each oriel window design complies with UK standards and current Building Regulations. 

Design Considerations Before Installing

An oriel window is as much an engineering feature as an aesthetic one. Proper planning ensures it looks stunning and performs flawlessly.

1. Structural Support
Most oriel windows are cantilevered and rely on concealed steel or aluminium frames tied into the building structure. Early consultation with a structural engineer is essential.

2. Orientation and Light
North-facing oriels maximise daylight without overheating. South or west orientations may require solar control glass. Integral glass blinds aren’t usually available unless the oriel window is a fully framed version.

3. Privacy and Overlooking
Corner oriels may overlook neighbouring properties. Frosted, obscure, or screen-printed glass helps maintain privacy.

4. Maintenance Access
Consider how the external glass will be cleaned. Frameless designs may need specialist cleaning poles or easy external access.

5. Ventilation
Most oriel windows are fixed units. Opening elements are usually not possible without visible frames. Plan for nearby opening windows or roof vents to maintain airflow.

6. Interior Integration
Internally, the projecting base can be finished as a seat, shelf, or display area. Consider insulation beneath for comfort. 

Is an oriel window the same as a bay window?

A Bay Window and an Oriel Window are similar in that they project outwards from the main elevation of a home. However, bay windows are usually supported by the structure itself, alongside bay poles and posts (although rarely designed to be structural). 

An oriel window will use brackets, supports or corbels and are fitted on ground or upper floors.

This guide explains everything you need to know — what oriel windows are, how much they cost, when planning permission is needed, and what to consider before installing one in your home.

In short, a bay window is built from the ground up, while an oriel window is suspended or projected from the wall — more technically complex but visually lighter and more modern. 

Glideline Oriel Window Systems

At Glideline, we design and manufacture bespoke oriel windows using premium aluminium profiles and structural glass. Our systems integrate seamlessly with contemporary façades, frameless corners, and minimalist detailing.

Every project is fully supported with:

• CAD drawings and load calculations

• Structural advice and specification support

• UK manufacturing and quality assurance

• Matching sliding and frameless window systems

Whether part of a large extension or a single feature window, Glideline offers the technical expertise and manufacturing precision required for these complex architectural features.

FAQs about Oriel Windows

Can oriel windows open?
Typically, no. Most oriel windows are fixed for structural and weathering reasons. Opening windows or ventilation needs should be considered at the planning stage.

How far can an oriel window project?
Projections usually range between 400mm and 900mm, depending on structure and design. Contact us for more information if you need larger windows.

Do they need foundations?
No. They are supported by concealed steel or aluminium frames fixed to the main building structure.

Are oriel windows safe?
Yes. They use laminated or other approved safety glass and are engineered to meet UK Building Regulations.

Can I retrofit one into an existing home?
Yes, but you’ll need structural assessment and possibly planning permission. 

Oriel Window Manufacturers with Nationwide Delivery. Contact us today

Oriel windows combine architecture, engineering, and design in one feature. They maximise light, add functional space, and deliver striking aesthetics inside and out. For homeowners, they represent an investment in both lifestyle and property value.

At Glideline, we manufacture oriel and structural glazing systems that meet the highest standards of performance and design precision.

Homeowners: Contact Glideline today for advice, cost guidance, and to discuss your bespoke oriel window project.

Trade professionals: Partner with us to access technical drawings, installation support, and premium UK-made systems for your next architectural glazing project.