Unlock savings with energy efficiency. Incorporate natural gas and energy efficiency in your new home or business If you're planning to build, contact us to see if natural gas is available. Natural gas is Montana's fuel of choice for year-round comfort for heating, water heating, and cooking. Rebates are available for new and existing homes, including qualifying new manufactured homes. Our E+ Home EnergyCheck provides an assessment that may identify energy saving opportunities for our space- or water-heat customers. Contact Us Efficiency Plus call 800-823-5995 visit NorthWesternEnergy.com/Eplus Kalispell Construction Center email CCKalispell@northwestern.com call 1-83-FOR-BUILD and follow the prompts. NorthWestern Efficiency Energy Plus Unlock savings with energy efficiency . Incorporate natural gas and energy efficiency in your new home or business If you're planning to build , contact us to see if natural gas is available . Natural gas is Montana's fuel of choice for year - round comfort for heating , water heating , and cooking . Rebates are available for new and existing homes , including qualifying new manufactured homes . Our E + Home EnergyCheck provides an assessment that may identify energy saving opportunities for our space- or water - heat customers . Contact Us Efficiency Plus call 800-823-5995 visit NorthWesternEnergy.com/Eplus Kalispell Construction Center email CCKalispell@northwestern.com call 1-83 - FOR - BUILD and follow the prompts . NorthWestern Efficiency Energy Plus