Gutter between 2 buildings

[Meadowbend99]

I haven't come across one like this before and am open to suggestions. I have a new build, 2 stories, attaching to an existing structure where there is currently a gutter at the low end of the existing building and I'm trying to figure out the best approach for water drainage from the existing building. Existing building is one story (old downtown structure with concrete roof panels and cmu exterior walls and front and side parapets. There is no rear parapet and water flows freely to the edge of the building with a standard gutter mounted to the end of the building. There isn't a downspout, just goes past the building/property and flows onto the adjacent property (which they also own). The new building will align with the full length of the back of the existing building with a 1/2" expansion joint. It will be 2 story w/ metal studs and stucco. We do not want to install an internal gutter system, however, also do not want to have a 5" gap between buildings just for the gutter (space is really limited, every inch matters). Also not interested in using pumps. photo

I'd love to hear about a gutter that could be installed at the end of the existing building that could maybe penetrate the side parapet and do a downspout. Has anyone seen anything like that? I'm thinking of building up the rear to create a valley with a trench drain. Anyone have a gutter manufacturer they'd recommend?

 

[MtnArch]

Make the roof one big cricket that daylights at the side walls to BIG scuppers, conductor heads and downspouts.

 

[RLGA]

Ditto to what Alan suggests above, but I would also include a curb on the existing building side and add a roof expansion joint between the curb and the new addition. This will help eliminate any leaking problems should the buildings have different movements or settlements.

 

[e hilton]

Add tapered insulation board and a membrane over the existing roof to direct the water to the side.