Theres more to choosing a conservatory than settling on a style..
1 - Use
What do you hope to get out of your new room? Will it be a study? Play room? An office/ Or will it just be an extra space to relax in? Whatever you choose, its use will determine how large you need your new space to be, and which layout will be best for you.
2 - Positioning
Think about the position of your conservatory. Those that face the South will receive the most sun during the day. If this is the case, you may need to consider extra ventilation and possibly add blinds to your conservatory to block out some of the harsher rays.
3 - Size
Once you’ve made a decision on your design, it might be best to check the dimensions of your house and garden to make sure you have enough space. It should not take up valuable garden space.
DO NOT FORGET ABOUT PLANNING PERMISSION!
If you do decide to go ahead and build your conservatory in England or Wales, you will not usually need planning permission, but to be on the safe side it is best to check first, by contacting your local council.