One of the universal things about business of all types is the "upsell". Every customer we get, especially when in a competitive bid process like roofing usually is, we have to take advantage of. Not in the bad connotation of "taking advantage" - we try very hard to deliver an above average product and service at a fair price and do not believe in going for the "home run" type jobs when we know there is not another bidder. We will only win so many bids a year so once we have a job we try to take advantage of the opportunity by earning more business, preferably while we are still there on that job.
The upsell makes it possible to bid very competitively on the base job if we know that 50% of the time we can add some other work to it after the bidding is done. We have a roofing and siding crew so our natural upsell is gutters and windows. You can make a very tight bid on siding if you know you can sell 8-12 new custom window installations at the same time on a better overall profit margin for the job. Even just adding gutters or covers on gutters adds a few hundred in profit, so if you add $1000 in profit on every customer throughout year you have something. Since the crew and equipment is already there, the costs are reduced for the added work already to ensure a healthy margin overall.
While windows and gutters are an obvious one for siding, we use the same idea for roofs. Upsell new gutters or covering the gutters and ask about skylight windows. The skylights happen naturally sometimes because they have old leaking ones that need repairing or replacement. This happened so frequently that we started just selling it as an add-on job. The same concept applies- all the equipment and ladders and safety gear is already there so it adds far less expense than typical so a much higher margin. Our goal is to average 50% of our jobs get an upsell of some type and by maintaining that average it lets us trim our bids a little tighter to get a few more jobs each year.
The difference in the crew time and skill level is minimal. The only real issue is that our roofing crews need to have more tools than the average roofers. When hiring roofers we use the extra training as part of the bonus to work for us and we offer to front the money for an assortment of professional grade power tools at the same time as we do for the fall restraint systems we require and then pay a stipend to cover that cost. In this way we show a few "extras" to potential hires as well so it also helps us in hiring and retention.