When building a house you are going to deal with 3 stages of the soil volume you are excavating.Bank Volume, natural state of the soil.
If you need to remove the excavated material it would help to know the swell percentage for the soil you are excavating. The volume of excavated soil will increase from its natural state(bank) to its disturbed state (loose). Excavating soil and piling it up will loosen it and the volume will increase due to void spaces/air pockets added to the material. If you are excavating an area with a volume of 200 cubic yards consisting of material with a 40% swell, you are actually looking at removing 280 cubic yards. At an average of 12 cubic yards hauling capacity of a truck, you are looking at an additional 6 to 7 truck loads. With larger excavations the cost due to swell can be significant and will add to your needed excavating budget.
The shrink percentage of the soil is useful for determining the amount of material that you need to keep on site for grading and back filling. If the 200 cubic yards of material had a shrink percentage of -10 and you would need to grade or back fill an area with a volume of 90 cubic yards then you would need to keep 100 cubic yards in bank volume of the material and now you would have to haul 140 cubic yards of site.