The office space supply is an important factor for highly skilled jobs, which generate a large added value and boost regional economic growth. Earlier studies for Poland have shown that office construction is concentrated around the capital city, while there is much less of new supply in the remaining regions. To understand office supply we need to compare it to regional GDP growth. However, at a regional level, new office supply comes in bulks, and this makes an econometric analysis infeasible. Therefore, the growth of the office stock should be studied, which is a smoother variable and can be linked to GDP growth. However, no official estimate exists. This article proposes a method to calculate the regional office stock in Poland with the help of various data from Statistics Poland. In the second step ,the growth of this calculated office stock is put into a relationship with GDP growth. We find a nonlinear relationship between these variables, which differs across the regions. This finding calls for further investigations.