Composite decking material is exponentially more expensive than wood products. Your choice of material costs will be a big factor also. Obviously the price will factor in too when it comes to footings versus floating. It's going to come down to how long do you plan on living there and to what degree are you comfortable in rolling the dice regarding frost heaving. I think you will end up finding that a permit is not required and as such a floating deck is legal. One that will withstand the ravages of time. Your HOA is recommending footings 48" below ground because IMO they would like you to build a "permanent" structure. If yours is going to end up 10" or 12" off the ground, does it need to go through that process? Perhaps not. My deck is elevated, requires railings and I can understand the need for permitting and inspection these days. There was one this past summer if I recall correctly. The reason is that deck failures with loss of life and personal injuries are big news across the nation these days. But a deck must be permitted and inspected. Now they only care about a shed over a certain square footage in which case a permit and an inspection is required. A deck, a shed, the township did not care. That was the case when I originally built mine 22 years ago. I'm going to venture a guess that a permit is not required for deck construction where you live. I'm not trying to confuse you, I'm just relating my experience. Twenty two years so far but who knows what I'll come home to next spring? With footings, my posts have not heaved but without footings the slab has not heaved.
It's because ground heaving due to frost is unpredictable. It makes one wonder why footings below the frost line are even required.
The deck has been in place for 22 years and I have had no issues with the stairs heaving. No footings, I just dug about four inches deep and put down sand before I did the pour. I poured a small slab for the base of the stairs and that slab is sitting on the ground. My support posts are in the ground with footings that are at a 48" depth. My stairs are 6' wide and start on an area of the ground that is pretty much level. The highest point of the deck I can just reach with my fingertips when standing on my tip-toes. The deck comes out on a 45 degree angle to the house. Click to expand.My deck is elevated because the property slopes off dramatically.