Firstly, the doors are not visually attractive. They are most commonly available in only solid white plastic. Whilst they are easy to clean and maintain they tend to discolour over time - becoming a musty yellow colour which is impossible to remove. Because they rely on gasket seals which are visible there is a noticeable black rim around the door.
Unless they are steel reinforced throughout (which is not standard) UPVC doors tend to warp slightly under heat. On hot days the door may stick and be difficult to open or close, and it may cause gaps where draughts can develop, lowering the insulation qualities of the door. The problem can be solved by adjustment to the hinges, but this is tricky and needs someone who knows what they are doing.
The doors pose many security issues - the cylinder locks fitted to most UPVC doors are easily 'lock-bumped' (a lock picking technique which uses a single 'bump' key to open all locks of the same type without damaging the lock) and the flimsy construction of the doors makes them a general security risk.
On the plus side UPVC doors can be cheap, and more versatile than wooden doors.
Why Composite doors are a better option
Composite doors are designed to be as customisable as possible, so you don't have to have a door which is the same as everyone else's. You can choose from 6 different external colours, each with a white internal to provide a light and airy hallway no matter how dark the external colour. They have an attractive timber wood grain finish with a clear protection layer to prevent it from fading and discolouring as well as giving it an attractive gloss finish. The GRP (Glass-fibre Reinforced Plastic) skin is as easy to clean and maintain as UPVC.
As well as a choice of colour there's a wide range of glass and glazing options available. Choose from a small arch window to a full panel, in either standard glazed glass or with an obscure glass backing for privacy and style.
To finish your door there's a range of hardware, from door knockers to peepholes, to fit your style preference.
On composite doors there are no unattractive visible gasket seals around the edge of your door, all you see is a great looking, functional door.
Composite doors are designed to suit any climatic conditions. They won't twist or warp like UPVC doors. The doors fit flush in the frame and have exceptional heat insulation qualities, keeping your home warm, draught-free and sound-proof.
Composite doors are far from flimsy. They are weighted to match that of a solid wooden door, with a solid frame which is comparatively thicker at 44mm than UPVC, which is only 28mm.
The solid design of the door keeps your home secure, along with the multipoint locking facility. The standard locks in composite doors have a high security, anti-bump, anti-drilland anti-pick cylinder to give your home the best protection possible.
Although UPVC doors were a reasonable alternative to the expensive, difficult to maintain, and often draughty wooden doors they are fast becoming outdated. The flimsy, cheap, faulty design of UPVC doors makes them a poor comparison next to the high detail and well thought out design of composite doors.