If you’ve got wooden decking installed outside, then another option is to raise it to the same level as your internal flooring, and minimise the gap between the levels.
While you’re unlikely to want to match the decking with the sort of hardwood flooring you’re laying in your lounge, wooden decking allows for rainwater to drain through, and if properly cared for will last for several decades.
Folding patio doors make a great addition to conservatories and garages that have been converted into living spaces. Since garages aren’t built with light dispersal in mind, they could benefit from the glazing that a bifold door provides. If your garage is set behind your property, then installing a large sliding door along the side of it will solve the light problem in a second, and provide you with an extra living area.
Given the considerable size of some doors (especially a bifold or sliding door), they can dominate exterior walls; even in larger properties. This may just exactly be the thing you're looking for! If not, you can always balance the large opening by using a long dining table that runs parallel to the door. It’s a perfect setting for summer parties, and it’ll ensure that the eye isn’t confronted with a large empty space.
For the sake of convenience, you might wish to install a canopy just above your bi-fold doors. The one pictured here is part of the building structure, but you can also install a retractable canopy.