Matchstick

Yes, higher or lower depending on heating system.

Yes, wooden deck exterior, most of it 18-24" off the concrete slab. Which of the heating choices I wonder is most adequate (cost/efficiency): radiant (Hydronic), forced air, or?

Thanks for the insights! We will incorporate a roof for about 2,000 SF of the patio area to cover the dining room. Depending on costs we might add a gazebo for additional partial coverage (covering all 5,000+ SF does get costly if it's a quality architectural solution like a fabric structure which runs $125/FT). So at this point we are looking to mitigate the cold air in the open section with a combination of heating solutions, including: electric heaters in cabanas, gas fire pits on the deck (some with upwards of 80,000 BTU's) and gas heat lamps. For under the deck we're looking at Hydronic Heating which has efficiency benefits: http://www.hydronicheating.net/. The pool is an integral part of the amenities and with it's glass side, a dramatic focal point of the patio - so have to keep that.

Another great idea! We had considered using tensile fabric structures as a way to frame the space, and also to give it a "sail" looking sculptural feeling to the space. Should we build these then it would be prudent to create them (or some) with a convex shape and a downward glance and equip a low noise "air knife" to funnel hot air such that it deflects to heat a portion of the patio. The pool water will be always heated to a level hotter then air temp so that should help a bit.

Great idea! This retractable roof idea could do the trick. Basically a series of semi-clear PVC panels on an "flowing" aluminum structure. Rolls out garage door style from a "stacked" group of panels accordion-like from a rectangular box. The semi-clear PVC helps admit the heat during the day. We could even make an alternate series of panels with canvas or sail material. The structure looks like a wave - unique and appealing open, with a material set of panels or with the PVC "glass" panels. One or both sides could draped to hold the heat in. It could even be installed with minor "tilts" so that rain would collect in just 2 or 3 "dip" sections of the wave structure For furnishings and fixtures are there colors, surfaces, forms or other considerations (plants) that would be advisable to maintain/retain the greatest amount of heat generated from the sub-floor vents and/or the PVC "roof"? Did you suggest that the humidity from a heated pool and spa should not be considered helpful and in fact would be incompatible if contained by a roof structure and "shared" with conditions required for a nearby restaurant?

Funny you say that. We are thinking of incorporating a steel rib beam structure that a fabric of some sort could be rolled out as temp cover - expensive but a possibility. We do plan on having 10-15 cabanas (with heaters) along the perimeter of the patio which will surround an above ground pool and spa. Plus there will be a 10-12 foot overhang (lattice with poly top, canvass or roof structure TBD) from the current building to cover a portion of the dining area, with clear marine isinglass roll down walls. The question is whether we can mitigate the chill in the balance of the area of about 5,000 SF with other methods to avoid a roof.

Thanks! Temp in So Cal ranges 45-70 during off season PM October-May. Intent is for year round use. Location is harbor waterfront so wind cab be an issue; a 4' glass wall facing the water perimeter is intended to mitigate. Floor heating will be vented out to the patio area which sits on thick concrete slab.

What are best methods to maximize heat retention in design and furnishings for a 8,000 square foot outdoor hotel patio. We'll start with forced air heat under the entire wood framed patio, gas/electric/infrared heaters mounted on walls and ceilings, select metal and stone based furniture and fixtures for heat retention, plus overhead canopies/umbrellas, firepits, etc. What else should we consider (besides sweaters) to keep people warm in an outdoor environment?