How do you extend the use of outdoor space without creating a structure that will be used for just a few weeks out of the year? Glass, construction techniques and weatherproofing materials come into play with garden rooms, verandas, car ports and roof lights.
Of the four extensions, garden rooms have the most complex planning permission. They usually count as permitted development, but there are height, size and coverage limits that can change that. Overstep any of the limits, and your development requires planning. Garden rooms require the most planning, and are the most commonly done incorrectly.
Verandas are even smaller and less costly, and extend covered space as opposed to creating a new enclosed room. These are used by people who want to enjoy their garden view without committing to a full glass structure.
The planning and cost implications of a car port and a garage differ, despite the fact that car ports get very little consideration.
All four have their uses and knowledge of the planning process goes a long way in ensuring you wind up with the extension you intended to have.
Most rooflights and skylights are add-ons to existing extensions. The primary question is, “Is it worth it?” This usually depends more on the insulation spec than on the glass. A poor specification rooflight will let more heat escape than the room gains in daylight.