Here’s the beginnings of a tutorial series on making a Maori Pa.
modeling
Making A Medieval Hut
Here’s a set of instructions for making a rude hut for your dark ages and medieval games.
Making Cork Walls
Adventures in Lead has a post on making very effective wall sections from cork.
Building A Pictish Figure Eight House
Mitch’s Wargaming and Modeling blog has a post on making a figure eight Pictish house. The result is wonderful.
Quick Hedges
The Warbard has a tutorial on making quick hedges.