Extract output of an intermediate layer from a trained u-net model in keras

I have trained a U-Net model in keras with images in input. The model generates image outputs. Now I have to extract the output from an intermediate layer using the trained weights. I tried creating a new model with the desired intermediate layer as output and loading the saved weights. But then the trained weights can not be loaded as the layers don't match. How to generate the output from an intermediate layer using the saved trained weights?