My builder didn’t need or ask for upfront payment, he charged me once his suppliers / subcontractor charged him. Had to say this was the builders suggestion - made me feel in control
We’ve just completed our extension c£100k. It has taken 18months to get here. Had we known each step it could have been half the time. Chose an architect who knows local planning department, we did but even then it took a resubmission to get it through. Fees should be about £4K for architect...