A quick carpentry job
I needed to replace some window sills, fairly straightforward, the trick (as is so often the case) measure, measure then think before making the cuts. It can be so easy to forget which bits need to be removed and which need to be kept!
Working from the back of the new sill, I roughly marked out the final layout including how much to take off the back of the new board, then went to work carefully marking out according to the measurements of the window opening. I was pleased with the final fit (even though the windows had been fitted slightly at an angle.