I would like to attach a screen porch to cover the current deck. The problem deals with three different roof hights: the house, the breezeway and the garage. They are all differnt heights. Is there a solution?
Your post is confusing. I suggest you post pictures, and perhaps a diagram of exactly what it is you wish to construct.
When you say you want to "attach" a screen porch, do you mean you want to build a permanent screened porch over the deck, or do you want to purchase a pre-manufactured screen porch and bolt it down to the deck so it can be removed later?
Assuming you want to convert your deck to a screened porch as a permanent modification, the first place to start would be with the building inspector, since you will potentially be converting deck space to living space, which could trigger permit and zoning board issues. Once you have established that it is OK to construct, the inspector will likely want to discuss the framing of the existing deck, to make sure it is adequate for use as a porch.
As for the three roof heights, I am not sure what you believe the problem is, perhaps you are concerned about getting the roof to look right?