12kVA to 16kVA upgrade

you should have a 80amp over current device in the meter box ,

Expensive breaker too ,

yes , the breaker in the bottom right hand side of meter box should be 80amp

16kva will also need a enhanced fuse board

OP post up some pictures of works

that board is not suitable for 16kva ,

Bus bar and panel wiring are too small , board should be rated @80amp , physically bigger busbar and panel wiring would be 16sq ,

Is there 25sq tails i can't tell from pics

And you don't normally series 2 63a mcbs like that( one at cabinet and one in main board) whatever he's at I don't know. It's hard to tell from pics of main board

for 16kva , the main isolater in the board should be a double pole 100 amp rated isolater , not a mcb , this will break both conductors neutral and live ,

I don’t think that mains cable is 25 sq , you would never get the main earth connection into the earth bar in that board , The enhanced board for 16kva has larger connections for the bigger cables ,and the rcd is also upgraded to 80amp too
show a picture of the meter box where the mains cable comes in ,

So looks like possibly the tails weren't upgraded to 25 then and that explains his reluctance to uprate the 63A main protective device at cabinet ?

Main Board not upgraded either from 63A

For some reason he's fitted 80 A single pole main isolation(assuming there is main isolation there , hard to tell)

2 B63s for main overcurrent protection and sub-board in series , not ideal either.

Ya .Looks like not much done on the contractor end.

Not familiar with Enhanced Boards . Didn't realize they were available off the shelf like that. As you said above then the existing 63A board should be replaced with a new Enhanced Board

When I was a rec doing enhanced it was all new installs and I made up my own boards in those days.

Didn't know they had 100A DP main isolator either but it makes sense alright on 80a main overcurrent protection . RCD also rated at 80A like you said.

I don’t like the Garo boards. We use Hager vaga range , the enhanced one is a joy to use , loads of room and big connection points

Looks like the contractor probably hasn't done any of his side of the work on the upgrade

Can't see any brown 25s there I don't think

All that's definitely been done is an 80A single pole main isolator fitted in an existing 63A board which isn't correct.

That should be 100A double-pole as part of a new enhanced board as outlined by JLspark above

Looks like probably 2 10s earths and a 16

So maybe 3*16 tails ?

agree with previous knowledgeable posters here

It doesn’t look like 25mm mains cables

It doesn’t look like there’s a 16mm earth cable to earth rod

Should be a double pole main isolator

Distribution board incorrectly rated for 80amp

is there surge protection in your distribution board

can you post a photo of complete board

Can you post a photo of complete meter cabinet

It’s also a requirement that you receive the certificate and test records