Increasing energy costs and stricter environmental regulations mean a more efficient, sustainable barn design is needed. More efficient heating, lighting, and ventilation equipment can help to reduce energy use, but designs that consider environmental and animal performance impacts are more intensive. An integrated system of environmental control, manure management, and feed delivery and storage will allow for greater efficiency and animal performance than individual parts. Energy use is generally evaluated on a per pig basis, but this does not always accurately indicate performance and efficiency. A more accurate measure of energy use would be to measure on per weight of meat produced. Rather than focusing on single inputs and outputs, systems should be designed and evaluated based on animal performance. Temperature can affect weight gain and feed efficiency in pigs, so having the optimal temperature is important to have good performance. Hot temperatures can cause heat stress, reduced gain, and more fat deposition. Manure handling affects air quality within the barn and emissions outside of the barn. Scraper systems have an advantage for manure handling as they reduce emissions, reduce the risk of hazardous gases within the barn, and would be suitable for use with an on-site anaerobic digester. During hot conditions, cooling is necessary to maintain performance, and floor cooling will keep pigs dunging in the right areas for partially slatted floors. An evaporative system reduces the need for ventilation by 1/3, and a geothermal system by 2/3. Creating more efficient building concepts requires larger capital input, so any designs would have to be offset by increased pig performance.