Download the files for this tutorial (please note, only a small version of the above image is available, please try the other free high-res images supplied)
Open the image and unlock the background. Take the Crop tool (C) and use it to encircle the entire image, pulling the upper edge upward so it falls outside the image. Double-click inside the selected part and the size of the image will change. Cmd/Ctrl+J the image to make a copy, then apply the upper layer with a layer mask.
Make a new layer and ensure this is placed on top of the other layers. Here we will place a perspective-aiding grid. Go to Filter>Vanishing Point and make two perspective fenceworks. Now go to Menu>Render Grids to Photoshop; this perspective grid will have to be adapted as the tutorial progresses.
Go back to the layer containing the building and select the windows on the left, duplicate your selection and drag the windows upward until the bottom six frames overlap. Proceed to Edit>Transform>Perspective and try to align the window with the Vanishing Point tool. Repeat this process twice. Then redo this step with the windows on the right.
When raising the building, it is a good opportunity to check the design possibilities. The building contains a white edge that can be used as a point of reference. Select the entire side of the building from the upper three windows and duplicate these. Drag this section upward until the bottom of this section touches the bottom of the second edge.
After the right side has reached its peak, it becomes clear something is off. Create a new perspective grid as explained in Step 2 and select the top two layers of the windows; drag these upwards and change the perspective in order to make everything add up once more.
After correcting the glass tower, it’s time to make more changes to the area between the glass wall and the right brick wall. When you take a close look at this area, you will see the perspective does not quite add up. Select the original wall and duplicate, repeat the previous steps to fix the perspective.
Place layer masks onto the layers and amend any bad joins between the wall to the windows with the Brush tool (B). Next, select the white beam and a part of the wall on both sides and adapt the perspective.
Repeat Step 6 for the brick and glass walls positioned further back on the building. Once you do this, it will become clear that the reflection in the window is off. Make a selection of the frame in which the original reflection is still present and duplicate this, placing this selection and lastly correcting the perspective.
The time has come to get rid of the old reflection. This will be done through use of the Clone Stamp tool (S). Press Alt while simultaneously clicking on a similar but correct reflection. Make sure the brush is set to the right size and then carefully brush over the faulty reflection. Work with precision and attention to detail.
Adapt the rest of the building as previous. Select the nearest brick wall, where it meets the large glass windows, and create a new layer on top of the modified bricks. Right-click the new layer and choose Create Clipping Mask. Select the Brush tool, set Opacity to 10, Foreground Color to Black and use the soft brush to apply shading.
Select all layers of the building and Cmd/Ctrl+G. Duplicate this map and merge the map into one layer with Cmd/Ctrl+E. Turn off the map and go to a neutral section of wall. Make a proper perspective selection and duplicate this. Duplicate this layer again, place this on top of the previous layer and modify the perspective.