Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Straw and hemp house passed 'safe'

A house made of hemp panels and straw is as fire resistant as houses built of conventional building materials, even at 1000 degrees centigrade, research has revealed.

Bath’s BaleHaus@Bath building, made from prefabricated hemp and straw-bale, had a panel used in its construction heat tested by a team from the University of Bristol.

The panel had to withstand the heat for more than half an hour, but lasted two hours without failing.

The house is made from prefabricated cells of timber filled with straw or hemp, rendered with a lime-based coat.

BaleHaus@Bath is part of a research project into how renewable building materials can be used for homes of the future. The research work has been funded by Carbon Connections and the Technology Strategy Board.

Construction materials researchers from the university will also be monitoring the house for a year for its insulating properties, humidity levels, air tightness and sound insulation.

The ModCell BaleHaus system is the brainchild of White Design in Bristol and Integral Structural Design in Bath. It was used last year by TV presenter Kevin McCloud to build an eco-friendly house in six days for the Grand Designs Live exhibition.

Readers' comments (2)

  • I'll admit that my understanding of fire is limited, but surely making statements on fire safety based on solely a heat test is insufficient?

    I'll grant that items can catch fire from excessive heat, but I always thought that something like straw would be more likely to catch alight from exposure to a flame. I would therefore wonder if a small fire, for example from a short-circuited kitchen appliance, could set a straw bale wall alight quite quickly? In which case the panels may not be as safe as conventional materials.

    Would any fire safety experts like to correct (or possibly agree with) me?

    Unsuitable or offensive? Report this comment

  • Hi Andrew,

    The fire test for the ModCell BaleHaus is a standardised test for building systems.

    The fire test chamber is a 3 m x 3m by 1 m open sided furnace. The building system being tested closes the open side. Twelve propane jet burners set parallel to the panel are lit and bring the temperature up to 600°C within 5 minutes and continue up to 1000 within an hour.

    To put this into context, paper will spontaneously combust at 357°C.

    After 2.5 hours the test was stopped.

    The targets were to demonstrate the system could achieve half hour then go on to a one hour fire rating. 2.5 hours is an outstanding result for any type of building construction.

    For the last 45 minutes of the fire test straw was the only material preventing the flames from escaping.

    I hope that reassures you that BaleHaus is actually safer than most forms of construction.


    Craig White

    Unsuitable or offensive? Report this comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.