[quote author=Mr.Gorp link=topic=233.msg4335#msg4335 date=1295656461]
Best type of foundation is some what subjective. What are your goals? permanent? warm? easy maintenance? easy to work on? Keeps out bugs? easy access?
"Spa Observatory" Sounds to me like a much more than an observatory? Is the spa on the bottom level? Built in, or attached?
Is 15×15 big enough or are their ordances to be contended with? (When we built our screened porch, it started as a 12×12, then ended up with 14×18 and wishing we'd added 2 more feet.
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Basically all of the above. This will be a permanent structure that has to blend into the neighborhood and be stylish in such a way not to harm anyone's property value. Since it is over 100sq.ft. it will require a permit and the type of rolloff roof will have to be stamped by an engineer. I want it to safely and securely hold all my equipment since it will have several telescopes as well as my imaging equipment in it. The whole design is dual-purpose as it will be wired for a hot tub but that won't be installed, easier to get passed for this use with the rolloff roof than just a observatory. The warm room will be to keep warm or if the house is sold used for changing in or to keep warm. Would love to go larger but the additional costs and steel required structure involved will get to complicated and costly.