This might help you pinch a few “pennies” or “Pounds” off the price of a gate or railing.
Steel comes to me in 6mtr lengths, at least on flat bar and round or square. So lets assume you want a railing 1220mm high, and your chosen railing heads are 150mm tall. The height of the ladder part of the railing after you take 40mm ground clearance off will be 1030mm. That means taking the thickness of the two horizontals into account. The upright bars need to be cut at 1014mm. This means from a 6mtr length you get 5 uprights and a “waste” piece of 930mm long. Technically not waste as its long enough to use on something eventually. But if the railings requireds lets say 30 upright bars as an example. you get 5 usable piece from each bar and to get 30 bars you need to cut 6 lengths of steel. If you adjusted the height down by 15mm so the railing was 1206mm then the upright would be 1000mm for the railing, and you now get 6 cuts form a bar meaning only 5 bars are required. If the railing needs to be 1220mm high from the wall the quick fix here would be to raise the gap underneath to 55mm rather than 40mm.
Being fair of cuts of 930mm long are a sizeable piece which can be used in some shorter. Lets just say that now handling those 930mm piece to now make a railing needing 700mm uprights. It takes more handling of a lot of short bars than it does a long bar, which slows making of the shorter railing down. Plus i have to store those off cuts until required. So just to avoid that i usually try and discount something that works out as perfect cut sizes.
So if you can be flexible on height it can sometimes save money, but this is something I would discuss with you, when you give me the sizes. It also applies to length but that is usually not possible to change. except on fencing panels where you have posts and a long run. Throwing in an extra panel over the length can change it so as less material waste.