<p>The CCI is calculated using the hedonic method based on elements derived from the quarterly survey concerning the five New Housing Cost Price Surveys (NHCP).The sampling basis is the Sit@del2 building permit database. Five months before the start of each quarter, a sample of 1,600 building permits is selected from the Sit@del2 database of building permitplanning permissions issued in mainland France for new housing to be used for residential purposes.</p>
<p>The sample is selected according to a sampling plan, stratified by region according to the type of construction (pure individual, grouped individual, collective) and the scale of the building permit. These building permits represent approximately 7,000 to 8,000 new dwellings, depending on the quarters of the years in question.The building permits selected in the first phase do not automatically lead to actual constructions (cancellation of permits, postponement of operations, etc.), or do not include all of the requirements for inclusion in the calculation of the Construction Costs Index.</p>
<p>In addition, the collection of contract documents may fail. All in all, around 500 construction operations will be suitable for calculating the index (second phase).</p>
