Posted: 08/11/2016 at 16:59
1. Depends upon your handyman ( handyperson ) and carpentry skills.
2. Concrete slabs as a base are fine if you are sure you will never want to have soil beds in there. If your usage might change, an interior gravel floor may be a good idea leaving the concrete for the actual frame base.
3. Horticultural glass is probably the cheapest but a better bet is the toughened safety glass. Polycarbonate sheets are fine but not as attractive.
4. You will need to provide shade at some point - probably even for your sun lovers. You can do this internally or externally with blinds.
5. The usual "classic" orientation for a G/H is for the ridge to run East/ West.
6. If your plants are tender ( house plants, etc. ) then you will need to provide heat over winter. You can provide frost protection by various means if necessary. It really depends on what you plan to keep in the G/H and, of course, your geographical location