To utilize the given space in the best way is the trick which is required. If you have a good thought you can maximize even a small space so that it appears to be big. Same is with the bathroom where you need to place all the things in order. The colour theme will greatly influence the space as light shades uphold the beauty and elegance of the open area. There is lot more which can be done by you.
Design a plan and then work according to it. The water pipes and other fixtures should be kept within the walls only. The separate space should be made to keep the necessary accessories but should be compact. You can even search for small sinks and showers to give a wider room to the bathroom. This is only possible if you sit with the interior designer and plan all the things before executing it to get the desired result.