<p>Additional material costs for the upgrade from standard ply to fire rated ply. &nbsp;</p><p>Original price per ply board was &pound;21.67 x 300 = &pound;6,500.</p><p>As per instruction to purchase fire rated board &pound;60 x 300 = &pound;18,000. &nbsp;Giving a total difference of &pound;11,499.00. &nbsp;&nbsp;</p>