Controls Retrofits, or retrofits to HVAC systems are typically excellent candidates for Option C. Building codes now require thermal insulation and efficient windows for new construction or retrofits. It also can perform energy retrofits and other energy management projects at larger facilities. They are still in operation with engine retrofits to accommodate modern maintenance. American Tractors, or AmTrac, in England, retrofits and rebuilds old Steigers. Along winglets on new designs, aftermarket vendors developed retrofits. A model predicts the corrosive agents exposure to avoid inspections and to sequence the retrofits. This order consists of new cars and retrofits of existing R142A cars for CBTC. Questionable cost-effectiveness is thus, seen as a barrier to widespread of deep energy retrofits. Ceiling panels are very suitable for retrofits because they can be attached to any ceiling. Seismic retrofits can be applied where earthquakes are an issue. The total cost of seismic retrofits was estimated at in 2004. With time, the Parker Center became outdated and was in need of expensive seismic retrofits. Software architecture recovery may be required as part of software retrofits.