What wood should be used for timber framed houses or doing stud walls?

For timber-framed houses and stud walls, softwoods like pine, spruce, and fir are commonly used due to their strength, lightweight nature, and cost-effectiveness. These woods are easily sourced and treated for durability against pests and decay. Additionally, they can be engineered for specific structural applications, ensuring stability and insulation in the building. Always check local building codes and regulations for specific requirements regarding wood types and treatments.