In his London Tradesman, Campbell works through the building trades in Chapter 31, beginning with the architect and the stone mason, continuing:
The Bricklayer comes next under our Consideration. He differs from the Stone-Mason as much as his Materials; his Skill consists, considering him as a mere Bricklayer, only in ranging his Brick even upon the Top of one another, and giving them their proper Beds of Cements; for it is suppos’d, the Architect directs him in every thing related to Dimensions. But a Master-Bricklayer thinks himself capable to raise a Brick-House without the Tuition of an Architect: And in Town they generally know the just Proportion of Doors and Windows, the Manner of carrying up Vents, and the other common Articles in a City-House, where the Carpenter, by the Strength of Wood, contributes more to the standing of the House than all the Bricklayer’s Labour. He works by the Yard; that is, is paid by the Employer so much for every Yard of Brick-Work, either with or without the Materials, and is a very profitable Business; especially if they confine themselves to work for others, and do not launch out into Building-Projects of their own, which frequently ruin them: It is no new Thing in London, for those Master-Builders to build themselves out of their own Houses, and fix themselves in Jail with their own Materials. A Journeyman-Bricklayer has commonly Half a Crown a Day, and the Foreman of the Work may have Three Shillings, or perhaps a Guinea a week: But they are out of Business for five, if not six Months in the Year; and, in and about London, drink more than one third of the other Six.
Campbell is not wrong to warn of the dangers of speculation. During the rapid expansion of London and Westminster in the eighteenth century, a successful bricklayer may set himself up as a builder and build a row of houses speculatively. Such projects did not always end well.
Mortimer, in the Universal Director, while not warning of bankruptcy, does illustrate the recent (in 1763) changes in funding house construction:
But of late years the capital Masters of the two branches of House and Ship Carpentry, have assumed the name of Builders, and Ship-Builders; for this reason, because they make an estimate of the total expence of a House or a Ship, and contract for the execution of the whole for the amount of their estimate; so that they take upon themselves the providing of all materials, and employ their own Masons, Plumbers, Smiths, &c. whereas formerly it was the custom form gentlemen and merchants to apply to the several masters in each branch, and employ them in executing their plans: this indeed is sometimes the case at present, but very rarely, particularly with regard to Houses, whole streets having lately been erected by Builders.