In　this　research,　by　the　installation　of　solar　collectors　and　photovoltaic　panels,　a　building　with　almost　zero　energy　emissions　is　designed　in　TRNSYS　software,　and　with　a　parameter　study　on　a　residential　building　located　in　a　typical　city,　the　optimal　design　conditions　to　provide　suitable　conditions　for　thermal　comfort,　and　the　electrical　power　required　by　the　building　is　suggested.　Also,　to　improve　the　investigated　system,　in　addition　to　the　two-dimensional　design,　the　three-dimensional　design　of　the　building　is　examined.　After　the　design　of　the　building,　it　is　observed　that　Bushehr　is　suitable　for　designing　a　building　with　almost　zero　energy　emissions　through　the　installation　of　solar　collectors　and　photovoltaic　panels　due　to　having　the　appropriate　intensity　of　sunlight.　Also,　due　to　the　suitable　radiation　conditions,　it　is　suitable　to　use　a　battery　to　store　electrical　energy,　and　also　because　the　cooling　load　required　to　provide　thermal　comfort　in　the　summer　season　is　high,　therefore,　the　use　of　a　diesel　engine　is　suitable　for　use　in　emergency　situations.　Among　the　different　fuels　for　starting　a　diesel　engine,　diesel　fuel　has　the　lowest　consumption,　and　hydrogen　fuel　has　the　highest　consumption.　©　2023　Elsevier　Ltd