wpqs said:

Single core cables are run inside plastic conduit rather than using twin core and earth in a PVC jacket. The cables are also multistranded rather than solid core, though for some terminations the wire is capped and crimped to give a solid core like end

Common practice in the UK for non-domestic installs - and also some domestic garages. If using UK accessories, ferrules are not always necessary because of the terminal requirements in the accessory standards, but ferrules can be used with Class 2 (stranded) or Class 5 (flexible, or finely stranded) conductors - given the caveat that with larger cross-sectional areas, ≥ 10 sq mm, ferrules on Class 2 conductors with a small number of strands (such as 7 strand) might be problematic until the terminal is tightened properly - espeically if they are not manufactured to the correct standards and crimped with the appropriate tools.

wpqs said:

Plastic backboxes are used rather than metal. This is because they are chased into limestone blocks, not brick, so metal backboxes tend to corrode.

Similarly, common in the UK (drywall boxes, plastic conduit system backboxes ... and sometimes chased in too, in older properties because of lime mortar and plaster causing the same problems).

gkenyon said:

ferrules can be used with Class 2 (stranded) or Class 5 (flexible, or finely stranded) conductors - given the caveat that with larger cross-sectional areas, ≥ 10 sq mm, ferrules on Class 2 conductors with a small number of strands (such as 7 strand) might be problematic until the terminal is tightened properly - espeically if they are not manufactured to the correct standards and crimped with the appropriate tools.

I suspect that the project will be using up to 4 mm² cable in which case I think that ferrules are definitely an advantage especially at the load end and in the neutral and earth bars which just have a screw in a hole.

I have tried ferrules on 16 mm² cable, but they seemed pretty pointless given that the strands are significantly thicker than the ferrules themselves.

gkenyon said:

ferrules can be used with Class 2 (stranded) or Class 5 (flexible, or finely stranded) conductors - given the caveat that with larger cross-sectional areas, ≥ 10 sq mm, ferrules on Class 2 conductors with a small number of strands (such as 7 strand) might be problematic until the terminal is tightened properly - espeically if they are not manufactured to the correct standards and crimped with the appropriate tools.

I suspect that the project will be using up to 4 mm² cable in which case I think that ferrules are definitely an advantage especially at the load end and in the neutral and earth bars which just have a screw in a hole.

I have tried ferrules on 16 mm² cable, but they seemed pretty pointless given that the strands are significantly thicker than the ferrules themselves.