In regard to 'Supersoft' 100mm thick rolls made from recyled plastic bottles which I used for loft insulation - this is a relatively light material, easy for DIY installation and importantly it does not cause any irritation to skin. Upper-storey rooms are notably cooler in summer as compared to previous standard fibreglass. A second layer applied a year later to achieve 200mm (300mm to previously hottest room) has further reduced summer extreme heat within the upper-storey rooms. The seemingly superior quality of 'Supersoft' insulation easily outweighs any additional cost of this material over and above fibre-glass. It's very satisfying to be contributing to the re-use of plastic waste at the same time as benefitting from lower heating bills.