Trying to add roof for a porch

[tdd3748]

I am trying to add a roof over a porch addition and I want to tie it into the existing house roof line.
When I select either perimeter or add by picking points as soon as select the firs location wall or point.  A window pops up that says "all roofs on this location will be deleted do you want to continue"
What am I doing wrong?

Thanks in advance to all who reply - Tom

[Allan Chesney]

Hi Tom,

If you are using V16 you should normally be able to add to an existing roof by Picking Points but not by perimeter. If I remember correctly this could not be done in earlier versions. If that is your situation, then go to Building Locations and create a new location with the same settings as the location where your existing roof is and insert the new roof on the new location. This is generally the best procedure anyway for additions and if the wall height is different, which it often is for a porch.

Allan

[garystan]

    Mr. Chesney :

                         Before I make an official reply,  I wanted to state that....when I want to add a roof over an added porch,  I usually just "extend" the roof.   I extend the roof by grabbing the appropriate handle and dragging it "over" the porch.  Of course, for the sake of reality,  I usually add columns to support that part of the roof.  This will work with  a plan involving just a single floor project.

                                                                                                                       garystan

                                                                                                                 

[Allan Chesney]

Hi Garystan,

Yes that can be a simple solution too, especially if the porch is the same width as that edge of the existing roof. If not it becomes more complicated, as the edge has to be 'broken' in a couple of places and just the narrower section  moved out. The options here to 'adjust support height' or 'maintain support height' were not available in previous versions so just draging the edge could also have serious affects on the existing roof.

If the wall height (or pillar height) of the porch is different to the main building, then a different location is the safest option.

Allan