How To Build A Straw Bale House

How To Build A Straw Bale House
Building With Straw Bale

Straw has been used as a building material for over a millennium, and it's not hard to see why - warm, renewable, plentiful and more durable than you might think if used right.

What Are The Advantages?

Straw is a renewable material, readily available as a by-product of arable farming. It has high insulation values (its 'U' value is far better than that required by building regulations, at 0.13W/m2K for a 450mm thick bale), and it's strong enough to support a two-storey building. It's also acoustically insulating.

What Are Its Eco-Credentials

According to Barbara Jones, author of Building with Straw Bales (see below), the UK produces 2m tonnes of surplus straw each year, so using it in place of brick or block is ecologically advantageous. Straw is low in embodied energy and has a negative carbon footprint. When used for building, its high insulation values should result in lower energy bills.

Would I Get Permission To Build?

There are no specific planning permission requirements for building with straw, as the straw is not on show on the exterior, but you must meet building regulations.

Is It Highly Flammable?

You might think a straw bale house is susceptible to catching fire, yet the straw is tightly compressed so there isn't enough air to support combustion and it is usually covered with render. There's nothing tasty about straw for rodents, and there are no cavities in a straw bale wall for rats and mice to run around in, though physical barriers can be inserted if you wish.

What Are The Disadvantages?

Water is the enemy of a straw-bale house, but this is easily counteracted by specific build techniques. Before the build consider paying for long-term dry storage; managing tarpaulins on site is heavy work. During the build, the straw must also be kept dry; one answer is to use a lightweight compressive frame, so that the roof can be put in place prior to the walls, which will cost more but protect against bad weather. The roof needs to be designed with a good overhang to direct water away from the walls.