The problem with cheap composite doors (and what to look for instead)

If you’ve been browsing for a new front door recently, you’ll likely have seen adverts with bold statements like: “Composite doors from £699!”

It’s tempting, especially when budgets are tight. But the truth is that the real cheap composite door downsides don’t show up until after installation. That’s when homeowners begin noticing cold air creeping through the hallway, locks sticking, warped panels and, worst of all, a door that simply doesn’t last and needs to be replaced in a few years anyway.

This blog is a friendly heads-up. We’ll explain why composite doors at the bottom end of the market often fail, the risks they bring (poor insulation, structural failure and weak locking systems) and what to look for instead. A quality composite front door is an investment that will save money on energy bills, keep your home secure and withstand years of harsh weather. At Advanced Glazing Systems, we’ve spent over 20 years helping homeowners pick the right choice for long-term value rather than short-term savings.

Cheap composite door downsides

Cheap composite doors cut corners in the areas you can’t see: the core, the skins, the hardware and even the installation. Here’s what that actually means for your home.

Poor insulation

Many budget composite doors use thin foam cores, low-grade GRP skins or poorly fitted door frames. The result is simple: heat loss.

Poor insulation leads to:

• Cold air entering the hallway
• Rooms taking longer to warm up
• Higher energy bills year after year
• A home that feels damp or draughty

Over time, the small initial cost saving disappears because you’re paying more to heat your home. A quality composite door with the right combination of materials, such as a solid timber core or high-density foam with double glazing, traps heat inside far more effectively.

Structural failure

A cheap composite door may look OK when it first arrives, but the problems usually appear as soon as the seasons change. Sudden temperature shifts cause thin skins and weak outer layers to move and flex, leading to:

• Discolouring of door slab
• Swelling in damp conditions
• Cracks around the hinges
• Surface bubbling

Poor manufacturing can also let moisture into the core, causing rot or insect damage. Experienced installers (like our own team) account for seasonal movement and use reinforced materials that stand up to extreme weather conditions.

Substandard locking systems

A front door is only as secure as its lock. Many budget composite doors are supplied with:

• Basic cylinders that can be snapped in seconds
• Shallow hook locks
• No protection against drilling or picking

Considering 85% of break-ins happen through the front door, a weak lock is a huge risk. A secure door should come with high security multi-point locking, a quality cylinder and reinforced components. Cheap doors often fail this test.

Shorter lifespan

A quality composite door has a long lifespan, often 20–30 years or more. A cheap one may only last a few years before the surface fades, the frame sags or the hardware breaks. That means more repairs or even a full replacement far sooner than you expected.

Increased repair costs

Budget composite doors are more prone to jamming, sticking and misalignment. It’s frustrating if you’re rushing out the door for work and the latch won’t budge. You may need regular maintenance, replacement hinges or constant adjusting just to keep the door usable.

For busy homeowners, this quickly becomes an irritation.

What to look out for when choosing a composite door

If you want a door that stands the test of time, here are the main features that truly matter. These are all included as standard with Advanced Glazing Systems composite doors.

Multi-point locking systems

A quality multi-point lock pulls the door tight against the frame, improves weather performance and significantly boosts security. Our doors come with Secure by Design locks as standard.

Double glazed units with argon gas

If your design includes glazing, make sure it’s not single glazed or low-quality glass. Argon-filled double glazing helps keep your home warm and reduces noise from a main road or busy street. It also improves thermal performance and lowers energy bills.

U-values

A U-value measures how effectively a door stops heat from escaping. The lower the number, the better the insulation.

Our Rockdoor collection achieves U-values as low as 0.83, which is incredibly impressive for a normal-sized front door. It means outstanding thermal efficiency with thick reinforced materials and tightly sealed frames.

GRP outer skin

Glass reinforced plastic (GRP) is strong, low maintenance and withstands harsh weather conditions without fading or cracking. Look for:

• A high-quality woodgrain effect
• Thick skins with consistent colour
• Proper bonding to the core

All our doors use tough GRP skins designed for long lifespan and stable performance.

Extensive hardware range

From letterplates to knockers to handles, hardware quality varies massively. Cheap doors use thin metal components that quickly pit or tarnish. We supply a wide choice of high quality hardware in various colours so you can design the perfect door.

Foam or timber cores

A solid timber core offers weight, strength and a secure feel, while high-density foam offers strong thermal performance with lighter construction. The right core is essential to long-term reliability.

Composite doors from Advanced Glazing Systems

We supply some of the best composite doors on the market from Endurance and Rockdoor. Each offers something different, but all three are known across the double glazing community for their quality.

Endurance

• 100% solid timber core
• 85+ designs and 19 colours
• Heat reflective skins
• Carbon balanced business
• Excellent thermal efficiency

Rockdoor

• Reinforced aluminium and steel inner structure
• Unique S-Glaze system so glass can’t be removed
• U-values down to 0.83
• Wide range of styles and colours

All our composite doors come in a huge range of colours, glazing options and hardware finishes. Whether you prefer something traditional or modern, we’ll help you design a secure door that suits your home’s kerb appeal and your budget.

FAQ

What is a composite door, and why is it a popular choice?

A composite door is made from various materials, including GRP, timber and foam. It offers strength, insulation and a long lifespan, which makes it a popular choice for homeowners wanting a secure, low-maintenance front door.

What colours are available?

We offer a wide range of colours across all our suppliers including greys, black, blues, greens, neutrals and wood effects.

Are composite doors better than timber doors or uPVC doors?

Composite doors tend to offer better security and insulation than traditional wooden doors and outperform a standard uPVC door in strength, lifespan and weather resistance.

To summarise

• Cheap composite doors often fail due to weak cores, thin skins and poor hardware
• Poor insulation leads to higher energy bills and cold air in your home
• Weak locks on cheaper doors put your home at risk
• A good composite door has strong materials, multi-point locking and low U-values
• AGS offers Endurance and Rockdoor for reliable long-term performance

Who are Advanced Glazing Systems?

We’re a family-run business founded in 2004 by John, Andrew and Julie Barnett. After working in the industry for years, we set up AGS with a simple aim: offer high specification windows, doors and conservatories at fair prices with genuine customer care.

We work across Essex and London and focus on no-obligation quoting and professional installation. Our products include uPVC windows, aluminium windows, composite doors, French doors, patio doors, conservatories and roof lanterns.

Our accreditations include InstallSure, FENSA, Secured by Design, TrustMark and Trading Standards Institute. We’re proud of our Trustatrader reviews and our 10-year guarantee on all windows and doors (5 years for glass).

If you’d like to design your new composite door or get a quote, contact us on 01277 230101 or sales@advancedglazingsystems.co.uk. We’ll help you choose a secure, long lasting door that genuinely stands the test of time.