This is a website I've found to be helpful on occasion. While not a cardboard house site, it allows you to create custom size items, such as cones, pyramids, etc. in various file formats. Can be helpful making roofs, bases for buildings, etc.

http://www.templatemaker.nl/

This one will contains an amazing array of objects of a variety of shapes. Your file will be a PDF, but when you print, if you choose to scale the printout, you can get it to be perfect for putzy stuff. Can you ever have too many truncated pyramid patterns?

http://www.korthalsaltes.com/

I see gazebo roofs and church steeples

Thanks for sharing