Renovation of commercial buildings was studied to analyze typical energy improvements and to determine the performance gap in relation to major NZEB level renovation. To provide input for Estonian long-term renovation strategy, building samples and interviews were used to study how the commercial property companies deal with the building renovation need in Estonia. Results show that in office buildings renovations improved energy performance marginally and a performance gap of about 40% existed after market-based renovation. About one third of trade buildings reached the NZEB level, but within the rest, the performance gap was about 50%. A common renovation cost was around 10 €/m2, but major renovation will need 130–150 €/m2. The main obstacle was the long, 20–30-year payback time and uncertainty of the measures for major renovation. This increases the risk of investment for a real estate company preferring max 10-year payback time. Interviewees pointed out, that tenants are not motivated to invest because the expected 2–3% saving in the sum of rental and energy cost seems invisible. To start the NZEB renovation, building owners recommended preparation of new energy or carbon taxes together with incentives and knowledge about energy efficient renovation.