yes

I think I saw on one of the news channels, that in New York they are allowed to do what you propose. I would google your question and it will turn up engineering programs.
It sounds wonderful. Good luck! Great guestion.

yeah because we live in Arizona so we have a flat roof, and lots of sun (too much sun) good question though i love it!! maybe i will consider making one with my awesome green thumb lol

wow! that would be cool!

tell me if you build it because i want to see it

Just wanted to say,What a COOL idea!

I think you would be able to build a greenhouse on your roof, but instead of a wooden stucture you would probably have to put a steel beam across, and have a flat roof, if you can afford to do this then to keep your house cool during the summer months put in central air. But then your going to need to either build stairway on the outside of your house to get to the greenhouse or a stairway going up threw the house.I don’t know but couldn’t you use plaxsie glass(it’s not spell right I know) or even bullet proof glass.But I think you need to check with your town or city or where ever you live cuz there are building codes that might not allow it.Or if they do your property taxes are going to really be high. What are you going to grow in the this greenhouse anyway, tomatoes plants and flowers? or “?”

Yes, it has been done; but as graveyardspunka stated you will have to clear it with the local building standards department.

A greenhouse cost 6 to 10 times as much to heat than a conventional dwelling.

Sloped glass is more susceptible to breakage and leakeage due to weather than verticle glass.

Glass is heavier than plastics but has a much higher transmission of light and has a lower expansion/contraction rate than plastics. You may have to use laminate glass on sloping parts of the green.

A conventional roof roof structure can last more than 100 years if maintained properly. Asphalt shingles with felt paper/water resistant membrane installed properly will last anywhere from 15 to 30 years before reshingling has to be done. Aluminum, steel, recycled rubber, plastic etc shingles (4 to 6 times the cost of asphalt shingles) installed properly can last for more than 50 years before requiring replacement. Slate clay (roof has to be designed for these tiles due to extra weight load) tiles have been known to be on buildings for over 100 years.

The greenhouse on the roof will cost more than a conventional asphalt shingle covered roof and likely more than aluminum, steel, recycled rubber, plastic etc shingle covered roof.

Building the greenhouse on it’s own foundation will likely be cheaper in the long run.

If you can build the greenhouse as an addition to the house, you can still benenfit from excess heating in the late fall, early spring. You will have to make sure the moisture does not damage the common wall. You can place drums of water below the floor of the greenhouse and circulate the air around the drums with fans. they will absorb heat through sunny days and give off heat through the night. This can help to offset the heating costs of a greenhouse.

Some points to consider:

Additional weight due to greenhouse structure and benches, soil, water, plants, etc. – Will your existing struct support it safely or will additional support have to be added?

Water and moisture containment:
A water barrier is required and drainage:
1 to take away excess water preventing leaks;
2 to prevent rot and hazzardous mold and mildew in
structures below greenhouse;
3 good insulation to reduce lower structure from
becoming too hot and will reduce the A/C load
in the summer.
4 heat recovery /transfer system to utilize excess heat to
heat the lower structure in the late fall, early
spring.

This should give you some insight to what has to be done to plan such an undertaking.

Yeah but you have to think is i practical, Adding a green house would be much safer and less worry just put it in your back yard