House price index is a statistic designed to reflect the average change of house prices across the country or a certain area. It ensures that the relative importance of different property types in different regions remains fixed throughout the life of the index. Different adjustment must be used as no two houses are identical. Therefore characteristics such as physical attributes of a house or its location should be included in the calculation if the index.
Rising house prices are likely to increase consumer confidence and consumer spending which lead to rising aggregate demand. This can have two effects. On one hand it causes higher economic growth. However, on the other hand, it might contribute to inflation. Increased consumer spending is usually aimed at imported goods thus higher house prices cause current account deficit.