What Is a Composite Door? A Comprehensive Guide

Doors in Wandsworth

A composite door is a door made from a combination of materials, rather than a single material such as uPVC or solid timber. They are a smart choice for boosting energy efficiency in homes without having to compromise on aesthetic appeal. 

Composite doors have only grown in popularity in the UK over the years, and they may be the ideal choice for your home. Learn the benefits of composite doors and what they’re made from in this full guide. Or, contact us to discuss our range of composite doors and order yours today.

What are Composite Doors Made Of?

Composite doors are made from multiple materials, put together in layers. The external part is generally a layer of Glass Reinforced Plastic (GRP, also known as fibreglass). These external panels will generally be fused to an internal frame made from uPVC. 

Inside this is another frame made from hardwood, designed to offer increased stability and rigidity. The interior is then injected with a warm polyurethane foam core that offers heat-retaining insulation. The doors are then installed within an outer door frame constructed from uPVC and reinforced with steel.

Benefits of Owning a Composite Door


The meld of materials used in composite doors makes them stronger than doors made from just one material. They will withstand a lot of wear and tear over time, and the external GRP material makes them extremely resistant to damage.


The steel-reinforced frames and internal solidity of composite doors make them both sturdy and fully secure. The level of security depends on the type of composite door, so it’s worth checking individual security specifications when choosing one.


A traditional timber door or uPVC door might offer good thermal properties, but they cannot compare to the A-rated thermal efficiency offered by composite doors. The precision-fit manufacture of a composite door also means it will sit perfectly in the frame and eliminate gaps which could cause draughts. This is a particular problem for single material doors – as they age, the material will warp or shift in its frame.

Low Maintenance

Composite doors offer the same aesthetic benefits as wooden doors, but with none of the upkeep and maintenance. Timber will need careful attention in order to prevent it from cracking, rotting, or peeling as it weathers quickly. Composite doors, meanwhile, only need an occasional wash with a cloth to maintain the same immaculate appearance.

Kerb Appeal

The aesthetic appeal of a composite door gives a great impression to potential property buyers, and it can even add value to a property.

What to Consider Before Purchasing a Composite Door

As with any product, there are also some disadvantages to owning a composite door:

  • They are more expensive than uPVC doors
  • They swell in hot weather
  • They will drop over time

The latter two are unavoidable problems and would happen to all doors, not just composite. In order to accommodate the swelling in heat, you should instead ensure the door is fitted to the natural swelling size that can be expected. This will involve making sure the manufacturer you are working with knows the perfect size for your door, so that sticking is avoided.

In order to accommodate for the door dropping, you should adjust the strike plate or the hinges. This will help it to close easily.

How Much Does a Composite Door Cost?

Are Composite Doors Worth the Money?

Composite doors cost more than single-material doors because they are made up of multiple composite materials. However, this also means that they offer long-term cost-effectiveness.

The thermal efficiency of composite doors means that you will save money on heating your property; more heat will be trapped in your home instead, so the thermostat doesn’t have to be so high. 

This, and the fact that you will not have to replace a composite door for decades, makes a composite door excellent value for money.

How Long Does a Composite Door Last?

Naturally, you will want front and back doors to be a long-term investment for your property. Composite doors are ideal for this because the durability of the material combination means they should last for about 35 years or so. You should only have to replace one if it is damaged or if you decide on something else.

The glazing on a composite door is also simple to replace. As it isn’t moulded to the door, it can be slotted into a pre-cut space. However, you cannot cut a new shape for a glass window into an existing door because this will compromise the strength.

Find Your Perfect Composite Door Here

A composite front door is an ideal addition to your home. Sash Windows London Ltd. provides stylish custom designs and a dedicated, experienced installation team who ensure your door is fitted seamlessly.

Contact us to discuss specifications and get a free quote, or explore our range of composite doors to learn more.