general builder day rate

If you mean working for someone else, then 100/120 about right, skilled workers like bricklayers then 140/160 for London.

 

I was working on a project with a small contractor - they were paying £350.00 per day for brickies. There is a MASSIVE skills shortage in London.

I mean SKILLS not an 'any-brickie'

 

I'm sure for architectural work, but the OP said general builder for extension work, maybe the rates could be a bit more than I quoted but not much more due to the amount of foreign imports over here, especially in London.

 

you will have to be more detailed in your idea of a general builder.
painters £ 130 day, decorators £ 150 day, tilers £ 200 day, chippies £ 225 day, plasterers £ 250 day, sparks £ 250 day, heating engineers £ 275 day, kitchen installers £ 300 day, brickies £ 320 day.
If you want someone able to do all of the above or able to supply and manage the above trades you can stick on 25%.
that is in west london for decent, reliable, reputable tradesmen. £65 day for any random immigrant you pick up from outside Selco.

 

One guy to do all that? You may find someone so bad at all those trades that they are willing to have a go but I can not see how they will be qualified for the gas and electric works required. That is going to be one enormous van full of tools. If the person was capable of fitting kitchens they would not be digging footings

 

Apart from the gas works it is quite common down here in Wales that builders do virtually everything on a build. A guy down the road has just put his son through college on a Gas cert course as this is one thing he couldn't do. Other than that he digs founds, lays bricks /blocks / plasters etc. He has a contract with a natinoal bedroom and kitchen supply company to keep indoor work coming in which is useful in Wales ! He did his apprenticeship as a carpenter and "grew" into other skills his finish plastering is probably about the finest you will ever see.