Wood Siding Repair

This picture is of wood siding on an addition of a house in a posh neighborhood. Believe it or not the house had been painted only one year previously. I have ground off the peeling paint with a ceramic wheel which does a good job of removal and feathering.
As near as I could tell there were two principle causes for the premature failure. Number one; the addition, in my opinion, was done by someone with little experience because among other reasons, the re modeler had far too many joints in the siding where he should have used one, long piece. It is sort of piece- meal. Every exposed butt joint had dramatic decay as you can see in the picture. I am not a qualified builder, but I think, on the whole, the addition had fundamental flaws. Failure is sort of built in on this one.
Number two; when the current owners had it re painted, the painter did a 'scrape, spackle and spray' kind of job. His preparation fell very short. So the paint job failed within the first year.
One thing I am sure of is that both owners thought they were getting good deals at the time.
We did the best we could given the budgetary constraints. I replaced a good many pieces of bad siding and rotten trim, eliminating many butt joints. I ground off the peeling paint to a solid, paint able surface. I used a marine grade epoxy primer on the bare wood and used heavy duty filler. I also gave the lady a 3 year warranty. So she and I will haggle the next three years over what is warrantable and what is chargeable. I just want them to have a nice house.
When you build or add on, use a builder who won't cut corners on your most important investment - YOUR HOME!