A post on Defiant Principality blog showed some paper/card houses for Medieval Town and Village. I bought one of the Medieval village (available from papel3d). They also make a Viking stronghold set as well - may be worth a look.
The buildings are 1:87 scale; great for 15mm, but a tad small for 25/28mm. I opted to scan in the most suitable ones and enlarge them by a factor of 1.5 and then print on 210gm thin card. They do need some stiffening, so some card supports are needed for the long buildings;
for A frame style buildings I just put a central stiffener in which works fine.
I'm also making up two small A frame styles buildings as well. After adding the thatched roofs I found I heed to touch the dotted 'fold line' out carefully with some thinned paint of a similar colour. Next step stick to bases and add some static grass - piccies to come when done.