Advantages

Two 6 mm panes with a sealed 16 mm cavity between them. The cavity stops the heat: Ug 1.0 is the insulation level of modern residential windows, while single-layer glass lets through about six times more (Ug ≈ 5.8). The tempered outer pane is four to five times stronger than ordinary glass; the inner laminated pane is two sheets bonded with a film, like a car windscreen, and if cracked it stays whole in the frame. The glass is Guardian, one of the three largest flat-glass makers in the world, with float plants in Germany, Poland and Hungary; the SunGuard SuperNeutral solar-control coating is chosen for the site in three tints (SN 51, SN 40/23 with 40% light transmission and a solar factor of 23%, SN 29), and AGC's Silverstone mirror glass (the Belgian maker, the largest in Europe) gives privacy during the day. The glazing unit, the tempered and the laminated glass carry CE marking under the harmonised European standards EN 1279, EN 12150 and EN 14449.

A dome is made of view: the skin is the product. With polycarbonate and PVC the view turns milky within a few seasons. In a caravan and a conventional building the view is bounded by the window; a large glazed wall is possible, but it makes the build more expensive.

The dome is roof and wall at once, so it carries everything a building carries. The structural report for SkyLodge checks the worst combinations under Eurocode: self-weight with wind (pressure and suction of 1.4 kN/m², roughly gusts around 170 km/h), with snow accumulated on the shallower parts (1.28 kN/m²) and with seismic load. The permitted deflection of a profile is 5 mm; the calculated figure is 4.1 mm. The load-bearing alloy EN-AW 6060 T66 is a structural aluminium under Eurocode 9.

The conventional building has the same level of proof, because the law requires it. A caravan is approved as a vehicle, not as a building, and with mass-imported domes the wind and snow capacity is usually not proven by calculation.

The sound insulation of a skin is measured by the index Rw in decibels: the higher the number, the less noise passes, and every extra 10 dB reads to the ear as twice as quiet. Three things stop sound: mass, an air cavity and asymmetry between the panes. The SkyLodge glazing unit has all three: two heavy 6 mm panes, a sealed 16 mm cavity and an inner laminated pane whose film damps the vibration, which is where the extra 3–4 dB over an ordinary double unit come from. Rain on the dome is heard as a distant whisper, not as a drum.

The membrane of a fabric dome is stretched cloth with no mass and no cavity: it is the drum itself, and the wind makes it flap. Polycarbonate is thin and light and resonates in rain. The thin caravan wall and the sheet-metal roof let through the rain and the conversation from the next plot. A massive brick or concrete wall is the quietest of the four. Quiet is one of the conditions international auditors weigh when awarding 4 and 5 stars, and one of the reasons fabric domes stay in the 1–2 star category.

The model compares the four concepts on the same 1,000 m² site over 50 years, with reinvestment at each refit cycle and the initial investment deducted from the result. SkyLodge wins because it earns like a 5-star hotel at the operating costs of a movable structure. The conventional villa is the safe deposit box: lower profit, but the asset remains. A campsite on a small site cannot repay its expensive underground engineering. The other dome starts cheapest and ends in the trap of fast depreciation: a low nightly rate, air conditioning without insulation and a new skin every four years.

As the site grows, economies of scale kick in: reception, spa, restaurant and administration are spread across more beds. The campsite gains the most from scale: at 5,000–10,000 m² the underground engineering finally pays for itself. The conventional resort runs into the density limits and into two years of building. SkyLodge scales linearly, because every dome is a self-contained unit with privacy in nature, and the shared block (reception, spa, restaurant dome) is added to suit the site. With fabric domes scale multiplies the skin replacements too: 35 covers every four years. The 10,000 m² results are calculated on the same model as 1,000 and 5,000.

Once physical depreciation is taken out of the equation, the psychology of the guest remains. The rarity of a glass dome is not a fashion but a shortage: a guest will always pay to watch the stars from bed. A campsite does not age, because it sells atmosphere and community rather than architecture. The conventional villa becomes a standard commodity after the first season. With a fabric dome the emotional collapse arrives with the first yellowing: the smell of stale plastic and mould, the loss of premium guests, rates down to the floor.