That's what I realized too when I was getting quotes from the electricians (hired them separately). They are just not keen on hacking concrete walls/ ceiling. But brick wall seems ok.

I stood my ground when I was getting quotes that I will not be putting plaster ceiling for my 9ft by 5ft wet kitchen part. I suppose the previous hacking work for electric conduit by my contractor's wet works subcontractor for the dry kitchen had already set precedence for the work required for the wet kitchen.

So they quoted a 'higher' price  cz they need to do hacking work in the wet kitchen and near main DB at living room which was fine with me.

The hacked area was not deep enough (didn't cut through the metal) so they didn't use conduit after checking with me. The cable was sticking out slightly after plastering and my contractor solved it by asking the tiler help tile over it.

Hmmm... That one is only a 8feet stretch. location is quite obvious.... There are too many cables running across it that I wouldn't even drill that part of the wall.

The electrician wanted to put 2 conduits in the concrete wall but it couldn't fit so only one.
1 of them contained all the usual cable 1.5mm +2.5mm Live earth neutrals.

The other one contained 2X16mm armoured cable and a 4mm earth wire... so that one he removed conduit before plastering.
Pic here: https://myglasgowkitchen.com/wp-content/upl...en-672x1024.jpg 
Pic contains the conduit (the lower one) which was eventually removed.
The rest of the armoured cables + earth on wall e.g. living room he used conduit... where else existing plaster ceiling (bathroom + bedroom) he tried as long as there were no structures blocking.

I guess it shouldn't be a problem?