Plans For Under B400K house

[dddave]

My former GF with whom I am still friends has a nice piece of land in her home village village with a proper deed.  She's in her 50s now and wants to build a small house on the property for her later years.  She will have a maximum of about B500K to spent total, finished and furnished.

I have been seeing posts on this and other forums about small houses in the B300k-400K range,(I assume unfinished shell) many using new, more efficient materials for walls and roofs.   

I tried to find online sites with drawings and photos of such houses, usually less than 80 sq/m of living space but have only found a few.  Can anybody direct me to some sites with a variety of such small houses?