| UA | = | UWAW+ UBGWABGW+ UVGAVG+ UOGAOG+ UFAF+ URCARC+ UCCACC+ UDAD+ FSPS | |
| Where: | |||
| UA | = | the combined thermal transmittance of the gross exterior wall, floor and roof/ceiling assembly area. | |
| UW | = | the thermal transmittance of the opaque wall area. | |
| AW | = | opaque wall area. | |
| UBGW | = | the thermal transmittance value of the below grade opaque wall area. | |
| ABGW | = | opaque below grade wall area. | |
| UVG | = | the thermal transmittance value of the vertical glazing area. | |
| AVG | = | vertical glazing area, including windows in exterior doors. | |
| UOG | = | the thermal transmittance value of the overhead glazing area. | |
| AOG | = | overhead glazing area. | |
| UF | = | the thermal transmittance of the floor area. | |
| AF | = | floor area over unconditioned space. | |
| URC | = | the thermal transmittance of the roof/ceiling area. | |
| ARC | = | roof/ceiling area. | |
| UCC | = | the thermal transmittance of the cathedral ceiling area. | |
| ACC | = | cathedral ceiling area. | |
| UD | = | the thermal transmittance value of the opaque door area. | |
| AD | = | opaque door area. | |
| FS | = | concrete slab component F-factor. | |
| PS | = | lineal ft. of concrete slab perimeter. | |
| NOTE : Where more than one type of wall, window, roof/ceiling, door and skylight is used, the U and A terms for those items shall be expanded into sub-elements as: | |||
| UW1AW1+ UW2AW2+ UW3AW3+ . . . etc. | |||