Both natural and artificial snow can be used as construction material. Natural snow, however, is not as dense as artificial snow and thus its physical properties and transformation processes are different. For snow constructions, artificial snow or machine-processed or packed natural snow is most popular because of its high density, which is important for the solidity of the structure. The density of these kinds of snow is near constant, which allows pre-calculations of how the snow structures will condense, bend, or deform under their own weight.

Because cold snow is harder than warm snow, snow sculpting in extremely cold temperatures can be very difficult. However, sculptors who dare the cold are rewarded in the finishing touches: details and surface finishing work out best on cold, i.e., hard snow. Naturally, snow structures are more durable in Arctic areas than in areas of mild winters. It is possible, however, to sculpt snow even in above-zero temperatures.

Clean new snow reflects sun radiation intensively: dry snow reflects 90% and even wet snow reflects 50% of the radiation that hits it. As snow becomes older and dirtier, the reflection factor diminishes. A work made from dirty and sandy snow will therefore quickly melt on the surface. At the same time, this melting causes more dust and dirt to condense on the snow's surface, further accelerating the melting. A work made from clean snow, however, glitters like spring snow when the sun's radiation warms its surface during the day while at night frost turns the water steam into thin, plate-like ice crystals.

The Condensation of Snow

In a packed block of snow, crystals bind with each other forming inter-crystal bonds. The same process takes place in a snow pile over a period of weeks: with new snow pressuring the old, the crystals first break and then bind with each other making the snow very dense. The metamorphosis of crystals can be accelerated by working the snow with a snowblower, a sieve, a snow brick maker, or by treading with feet.

The density of unpacked snow is very low. As such it can only be used for building pile-like walls less than 1.5 meters tall. The density of natural snow can be increased by collecting the snow into piles in which the structure of the crystals changes and the snow condenses. Dense, wind-packed snow can also be found in nature along riversides and in fell areas.

For tall walls, load-bearing structures, and snow sculpting blocks, natural snow must be mechanically packed into molds, for example. Snow is usually shoveled in 20-centimeter layers and packed tight after each layer. Useful machines for increasing the density of snow and the solidity of the structure include a tractor snow blower and a dipper used in sifting soil . As the snow blower blows the snow into the mold, the snow's density increases and the structures will become solid. It is helpful to use a valve to direct the snow from the snow blower into the mold.

Artificial snow is dense enough for building small vaults, walls, and towers up to five meters. Working artificial snow makes it even more condensed: piling the snow and working it into the structure increases the density slightly, while using a snow blower or a dipper will improve the quality significantly. This is the result of breaking up the lumps of snow and spreading the water content evenly into the snow.

Snow packs under its own weight. Thus, a dome shape which creates compression pressure is well suited for a snow structure. However, it is important to bear in mind that condensation causes the top of the dome to sink a bit. In tall (>10 meters) snow structures or in large vaults the condensation of snow is significant due to the snow's own weight and the pressuring tensions. This can cause great deformations that can result in unbalanced sagging and tilting.

The wetness of snow and external conditions affect the binding of snow crystals. In sub-zero weather, the water in the snow freezes, binding it tight and hard. Thus, wet snow can be added to increase the density of snow.