"A" frame 1st floor

Hi all,
Anyone know how to make an "A" frame wall for a beach house which will accept a central window?
I've tried geometric shapes such as wedges etc and a small rectangular wall as the core "in which the window is fitted" all of this works but when applying the final texture all the joins show up where geometric shape or slab meets wall etc no matter how accurately they are placed.

See screenshot for better detail of what I'm trying to achieve.

Cheers

You may want to take a look at this Help Database Article on how to build an A-Frame structure: http://www.homedesignersoftware.com/...?faqNumber=452

Thanks guys!
I lowered the 1st floor walls to effectively nil height then put 2 roof planes in and this was why I thought I'd have to custom build something for the "A" wall.
I'll redo the 1st floor and then without lowering any walls I'll just manually place the 2 roof planes , then the "A" walls should auto form.

Cheers