Unfortunately chairman don't make the law.
But it's actually unclear whether a change in the law would have to take place. So as above to suggest it would be "illegal" is technically incorrect.
Read on. http://www.fsf.org.uk/campaigns/safe-standing/safe-standing-facts/
I suspect there is a technical possibility of adding a tier to the East. Technically I reiterate.
Would involve raising the roof and supporting the structure whilst doing it.