Find your background and duplicate the layer, make a selection of where you want to put your house and press Ctrl and j to make a layer on the selection. You do not move this layer all as it fits perfect to the background.. Place your house in a new layer and position it between the selection you made and the background copy. Make sure you have the auto select ticked at the top left hand side, select the cut out layer from the layer palette and take the opacity down so you can see the house and the cutout together. resize the house to fit to your liking and they put a mask on the cutout layer. by using a brush with a feathered edge you can mask parts of the cut out so the house looks to be inside the roots or what ever you use as your background layer. By putting up the opacity you can see how it is looking and if needed resize and move. When you have the house as you want put the opacity of the cut out back to 100. I did take the brightness of the house down a bit to make it look as though it was in the shadows..Using a mask makes it easier to me as you can always put back what you have taken out if needed.. I always work on a duplicate layer then if things do go wrong you can delete layers and not have to get the original picture back..With the pictures I hope you can understand how I did it...