There are a variety of replacement doors for utility cupboards:

Replacement Doors for Electric Meter Cupboards.

Flush fitted, these are the 'built in' type that show only a small meter cupboard edge and door but much deeper inside the wall. The sizes are Standard ( 383mm wide x 550mm high), Medium ( 426mm wide x 625mm high) and Large (509mm wide x 737mm high). Available from Mitas Composites Tel: 01782 375450

Permali Electric Meter Cupboard Doors, these are small size (365 wide x 557 high) and medium size ( 427 wide x 624 high ) both 'flush fitting' in other words, there the electric meter cupboard is sunk into the wall. Available from Mitas Composites Tel: 01782 375450, AC Plastic Industries Ltd; Tel: 1256 329334 . KMG Group; Tel: 1453 791616 .

Replacement Doors for Gas Meter Cupboards.

There are three main types of gas cupboard doors for the following meter boxes.
Built-in
Semi buried
Surface mounted

The current built in gas cupboard meter door is about 383 wide x 548 high
The obsolete built-in gas cupboard meter door is about 455 wide x 539 high

The current surface mounted gas meter box door is about 340 wide x 380 high
The obsolete surface mounted gas meter box door is about 410 wide x 210 high

The above gas meter doors are usually white

There are four main types of Semi-buried gas meter cupboard doors.

Transco Semi-buried Composite 479 wide x 362 deep
Transco Semi-buried Aluminium 479 wide x 362 deep
Semi Buried gas meter composite cupboard 415 wide x 440 deep
Semi Buried gas meter aluminium cupboard 415 wide x 440 deep

The above gas meter box doors are usually brown.