This freeing up of space to be added to the already existing living space needs proper planning. Of course the loft conversion companies can guide you and suggest some ideas as to what can be done out of your loft. You can utilise their ideas and come out with a plan that best suits all your requirements. And this should be within your budget too.
It is ultimately you who are going to use the space on the loft after loft conversion. So it is you who has to decide what you would want out of the loft. And the planning should be such that it puts your comfort level to a higher grade and most of the space is used judiciously and made full use of. The creative side of the family will come to the fore at such a time and will give a lifetime benefit.