It is hereby declared and agreed that anything done by the lessee, mortgagor, or occupier of any building hereby insured whereby the risk of loss or damage is increased without the authority or knowledge of the freeholder, mortgage or lessor shall not prejudice the position of the freeholder, mortgage or lessor under this policy if the freeholder, mortgage or lessor shall immediately on his becoming aware thereof give notice in writing to the insurer and on demand pay such reasonable additional premium as the insurers may require.
