 Section 1 ( 3 ) of the 1971 Act specifies that offences under section 1 , where the destruction or damage is caused by fire , shall be charged as arson . It would seem that courts adopt a purposive view in relation to the lawful excuse defence in relation to arson , as in R v. Hunt ( 1977 ) . The defendant , wishing to highlight the lack of fire defences in an old people 's home , set fire to it to demonstrate the risks . He claimed an honest belief in that by doing this , he had a lawful excuse within section 5 ( 2 ) . It was held , however , that he had not actually been acting so as to protect property . Although the court assumed that his belief was honest , it ruled that his intention was to draw attention to faulty fire defences rather than to defend the property itself . 
