The following graphic is of a 24' diameter structure that I have just finished building. My cost for roofing (elastomeric waterproofing coating), lumber, bolts, screws, nails, windows (double pane insulated with wooden sash), and doors (insulated metal) was approximately $2937.39 with an extra $149.31 spent for pattern and jig lumber. Of this amount, approximately $1400 was for the lumber, hardware, and sheathing for the basic dome without awnings, roofing, and kneewall. 10/20/97. The time required for the basic fabrication is about 72 man hours. This would be for a trained worker using simple jigs in a proper environment. This equates to 9 working days or 12 weeks of part time work of 2 hours every other day. updated 11/23/97
The following is a photo of the 24' dome. The kneewall at the time of the photo had not been primed and coated. The roof turbine shown at the top of the dome is tied in with the wedge channel between the panels in order to ventilate the roof structure whenever the inside surface is finished.
I highly recommend using a reflective material for the roofing to prevent the roof from acting as an energy absorber and re-radiating the collected heat to the interior of the dome. Unless the insulation used has a radiant barrier, such as an aluminum backing, standard insulation has little effect on radiant energy.
For larger plan areas, simply add domes together. The window and door awning panels are the same dimensions and can be changed from one to the other. The awning is designed in such a way to join two same size domes together.
The following photo shows how the second floor joist rest on a simple 2x10 joist hanger which has a 2x4 ledger. The joist are also supported by the 1st floor dividing walls.
