The walls - hemp or bricks?

cartoon boy

I say hemp.

I've been thinking about this...

Hemp grows in fields, it is a renewable resource and it uses up carbon dioxide!



photo of hemp plant

Walls can be made from a type of concrete that uses hemp plants. Stringy fibres are taken from the plant and mixed with lime cement. This makes a product called hempcrete.

When the hemp plant is growing, it takes in carbon dioxide from the air. A square of hempcrete wall measuring 1m by 1m will take in 40kg of carbon dioxide. Reducing carbon dioxide helps to reduce climate change.

Using hempcrete costs around £125 per square metre. It takes about the size of two football pitches to grow enough hemp plant to make a typical house.

Let's find out how to make walls using hemp

cartoon girl

I say bricks.

I've given this some thought...

We could never grow enough hemp for all the houses we need to build.




Traditional building bricks are made from clay and baked hard in an oven. This takes a lot of energy. To make enough bricks to build 1m2 of wall produces 100kg of carbon dioxide. This adds to climate change.

Using bricks to make walls for houses costs around £125 per square metre.

Hemp sounds good, but I think we would need too much to make a whole house!

Let's work out how much hemp we'd need to grow to make a house



talk partnerssnowballingthere's a great opportunity to get your class talking