At first I made a frame with lumber as you can see in the picture above.
The length of the frame is 205cm and width 130cm. The smaller slats are for support and are 60 cm apart from each other except the most left slat. This wil later come in handy to fit the Rock wool pieces in which are each 60cm wide.
2.The next fase is to cover the frame with fabric. I went to the local DIY store Kwantum and got a thick, sturdy fabric which is usually used to make pillows or curtains.
3m long and 1.5m wide for €15!! Next, I made myself a cup of tea and took all the time I needed to prepare the next step. You don’t want to rush this one cause you’ll later end up with wrinkles which you won’t get rid off. I used an ordinary hand stapler to secure the fabric all around the frame.
3.Then I filled the gaps in between the slats with the rock wool and it will look something like this in the end. I had 2x270cm long pieces of lumber left which I finally used diagonally across the entire panel to prevent the rook wool from falling out.
4.The final step was to place the panel in front of the windows. The dimensions of the panel and the window frames are the same so I could easily place it against them although I used 4 spacers behind the panel to leave a little bit of air in between the windows and the panel itself. In the top corners I let two screws stick out to prevent the entire panel to fall down. And there you go!!