If the ceiling of the new addition can be lowered an inch or 2 this gives us room to build a truss to match on the roof top.
How to match a roof addition.
But it can be extremely difficult to match new materials to old.
The best way to tie your addition s roof in with the rest of the house is to take cues from the existing architecture.
So if your house has casement windows for example oversized crown moldings or wide plank floors you ll likely want to repeat those design elements in the new addition.
Rather than a single slope a gable roof consists of two slopes that meet at a peak running down the middle of the roof.
You may need a structural engineer to help with design of trusses and rafters.
Also try to match finish materials such as siding roofing and trim.
Tying a gable roof into an existing roof is a long expensive project usually undertaken only when there is a major addition or renovation to a house.