The likes of you and I being asked are virtually zero , they will be looking for large accredited firms not small one man bands or a company with a handful of vans , it will be the big firms that will get the contracts and as usual I expect the rate will be very poor money wise , not worth bothering with , I was talking to one of my customers who is dealing with this very thing for my local council , as a start you need to be chas registered or similar , be iso 90001 accredited, have company policies about lgbtq ,religious and sexual orientation and equality and fairness policies,waist management policy’s ,thus is just the start ,carry on with the windows and dont worry about it there will be no money in it that I guarantee, they will be paying peanuts .