I WORKED IN THE TRADE 24YEAR+ AND IS ABOUT RIGHT FOR A COMPANY LIKE THAT. COULD BE DONE FOR ABOUT £6000 IF YOU LOOK AROUND. WE FIT 28MM "A" RATED GLASS ALL THE TIME NOT MANY COMPANYS FIT 24MM ANY MORE SO WHAT THEY WERE TALKING ABOUT IS RUBBISH. A GOOD LOCAL RECEMENDED TRADESMAN IS YOUR BEST...