Types of Internal Doors

Internal doors are a key part of most UK homes, providing privacy between rooms while also helping define the look and feel of your interior. Even open-plan homes often use doors for bedrooms, bathrooms and other spaces where privacy is key.

There are many types, styles, materials, colours and finishes of internal doors to choose from, ranging from traditional panelled doors to modern flush, glazed and space-saving designs.

In this guide we take a look at the most common options and what to consider when choosing the right internal door for your home.

Internal Door Sizes

Internal door sizes vary depending on the age and style of your property. In many modern UK homes, door openings use standard dimensions, with a common internal door size being 762mm wide x 1981mm high (2ft 6in x 6ft 6in). However, older properties often have non-standard openings, so always measure the existing door and frame before buying a replacement.

Note: When measuring doors you should always measure 3 different points (e.g. top, middle, bottom) as sometimes these can vary.

>Older properties often have non-standard door openings, so accurate measurements are absolutely essential when choosing a replacement. Measure the existing door and frame carefully before ordering. If a standard internal door will not fit, a made-to-measure door from a manufacturer, joiner or carpenter can provide the correct size.

How to Measure an Internal Door

Before ordering a replacement, take accurate measurements of the existing door. As commented above, measure the door width, height and thickness in several places, as older doors and frames can vary slightly. Check the frame and door edges for shaping that could affect the fit.

Door thickness is particularly important. If the replacement door is thicker than the existing one, the hinges and door stops may need adjusting rather than simply swapping the doors. Common internal door thicknesses include:

• 35mm
• 40mm
• 44mm – commonly used for fire doors, which are typically 44mm thick

Door Linings and Door Sets

A door lining, often called a door frame, is the timber framework fitted inside a wall opening. It consists of two vertical side sections (jambs) and a horizontal top section (head). The lining must be correctly aligned and square so the door opens, closes and fits properly without sticking and binding.

A door set is supplied as a complete unit, normally including the door, assembled lining, hinges and door furniture. Because it arrives ready to install, fitting can be quicker. However, a door set may be less suitable for older properties where existing openings can in many cases be uneven or out of square.

Types of Internal Doors

Internal doors, also called interior doors, are available in a wide range of materials, finishes and designs to suit the many different rooms and styles of home. While there are many variations, most internal doors fall into four main types, each offering different benefits for appearance, privacy and practicality.

Flush Internal Doors

Flush internal doors have a completely flat, smooth surface on both sides. They are available pre-finished or unfinished, ready for painting, making them a simple and versatile choice for many UK homes.

They are particularly suited to modern and minimalist interiors and are widely available from builders’ merchants and DIY retailers. Depending on their construction and intended use, flush doors can also be made for exterior applications.

One of the main advantages of a flush door is its versatility. It can be trimmed or adapted where permitted by the manufacturer and fitted with different door handles, locks and furniture.

Flush doors are available with either hollow-core or solid-core construction. Solid-core versions provide greater strength and can be manufactured for applications such as fire-resistant doors when correctly specified and certified.

Panel Internal Doors

Panel internal doors have recessed or raised sections that create a traditional or contemporary decorative pattern. They are available in many panel configurations, from simple two-panel designs to more detailed layouts.

They can be made from timber, engineered wood or moulded sheets fixed to a door frame. Modern panel doors are available in a wide choice of finishes, colours, materials and glazed designs, making them suitable for almost any interior.

Panel doors are also available with fire-resistant ratings where specified for the correct application. If choosing a glazed panel door, make sure the glass is suitable for use in a door and meets the relevant UK safety requirements.

Glass Internal Doors

Glass internal doors allow natural light to pass between rooms while giving an interior a bright, modern feel. Many are designed to fit standard door openings, with clear installation instructions supplied by the manufacturer.

For unusual or non-standard openings, made-to-measure glass doors can provide a better fit. Styles range from clear and smooth glass to frosted, textured and decorative finishes, offering different levels of privacy.

Safety is essential when choosing a glazed door. Always use glass that is specifically manufactured and certified for door applications and meets the relevant UK safety standards. Always check the manufacturer’s specification before buying or fitting the door.

Framed Ledge and Brace Internal Doors

Ledge and brace internal doors are a traditional choice, particularly suited to cottages, period properties and more rustic interiors. Their simple timber construction gives them a distinctive character that can, when done well, also work in modern homes.

Typically made from tongue-and-groove timber boards supported by horizontal ledges and diagonal braces, these doors are strong and durable. Oak and other timber options are available in a range of finishes.

Depending on the timber thickness, a ledge and brace door can be relatively heavy and may move slightly as it responds to changes in surrounding moisture and temperature.

To ensure longevity and also that the door itself is in-fitting with the style of it’s surroundings, correctly fitted hinges and suitable door furniture are also very important.

French Internal Doors

French internal doors are ideal for large openings where you want the flexibility of an open-plan layout with the option to separate rooms if and when needed.

Most French doors have large glass panes, allowing natural light to pass between rooms while the doors are closed. This can help adjoining spaces feel brighter and more connected.

When fitted between a living area and a patio or garden, French doors provide a wide opening when fully open, creating a natural link between the indoor and outdoor spaces.

Pocket Internal Doors

Pocket internal doors are sliding doors that open into a concealed cavity within the wall. Unlike hinged doors, they do not need space to swing open into the room.

This makes pocket doors an excellent space-saving option for smaller rooms, narrow hallways and compact homes. When opened, the door slides completely into the wall, leaving the doorway clear and maximising usable floor space.

When closed, the door provides a clean, modern finish, with the sliding mechanism hidden from view inside the wall cavity.

Bi-Fold Internal Doors

Bi-fold internal doors fold back on themselves as they open, making them a practical space-saving option where a traditional hinged door would not easily fit as it would take up valuable space in the room.

They work particularly well across large internal openings. Depending on the design, you can open the full doorway or fold back only part of the door, giving you greater control over how the space is used.

Available in a wide range of styles, finishes, designs and materials, bi-fold doors can suit both modern and traditional interiors and if done well, they provide a clean, contemporary style that can be subtle or emphasise an overall look and feel.

Barn Internal Doors

Barn internal doors are a style of sliding door inspired by traditional timber barn doors. Instead of swinging on hinges, the door slides along a track fitted above the doorway, making it a useful space-saving alternative.

With their distinctive rustic appearance, barn doors are particularly suited to farmhouse, cottage and period-style interiors. They can also add character to modern homes where a traditional or industrial look is wanted.

Pivot Internal Doors

Pivot internal doors open by rotating on a pivot mechanism rather than using conventional hinges fixed to the door frame. This allows the door to swing smoothly in a distinctive way.

Their clean lines and contemporary appearance make pivot doors a popular choice for modern and minimalist interiors.

However, pivot doors can require more space to operate than some other door types. The position of the pivot means part of the doorway can remain occupied as the door opens, making the actual opening smaller, so they may not be ideal where space is limited.

Louvered Internal Doors

Louvered internal doors have angled slats that allow air to circulate through the door. This makes them particularly useful for wardrobes, utility rooms, laundry areas and airing spaces, where ventilation can help reduce stale air and moisture build-up that can spoil clothes and make them smell musty.

They are available in a wide range of styles, designs, finishes and materials, making it easy to find a louvered door to suit both traditional and modern interiors.

Now you know the main types of internal doors and door linings, you can choose a style that suits your home. Once you have your new door, the next step is to fit it correctly and for that, see our guide to hanging a door for step-by-step help.