# Simple Building Life Cycle Energy Usage Model

## Class Name

• RSimpleBuildingLifeCycleEnergyUsageModel

## Location in Objects Pane

• Models > Model > Consequence > Environmental > Simple Building Life Cycle Energy Usage

## Model Description

### Model Form

• This model produces the lifecycle energy usage in a building at a coarse level of detail
• Pre-use phase
• $${E_{PU}} = {a_f}({n_s}{i_{pu}} + {i_p})$$
• Operation phase
• $${E_o} = {t_{des}}\left( {{{24(3600)(A({r_{ww}}{U_{win}} + (1 - {r_{ww}}){U_{wall}}) + 0.33NV){D_{HDD}}} \over \eta }} \right)$$
• End-of-life phase
• $${E_{EoL}} = {n_s}{a_f}{i_{eol}}$$

• No

## Properties

### Object Name

• Name of the object in Rt
• Allowable characters are upper-case and lower-case letters, numbers, and underscore (“_”).
• The name is unique and case-sensitive.

### Display Output

• Determines whether the model is allowed to print messages to the Output Pane.

### Footprint Area

• $${a_f}$$ = The building footprint area in m2.

### N Storeys

• $${n_s}$$ = The number of stories.

### PU Intensity

• $${i_{pu}}$$ = The energy intensity for the pre-use phases in J/m2.

### Parking Intensity

• $${i_p}$$ = The intensity for the presence of underground parking in J/m2 of parking.

### Surface Area

• $${A}$$ = The surface area of the building exterior in m2.

### Rww

• $${r_{ww}}$$ = The window to wall ratio.

### Uwindow

• $${U_{win}}$$ = The window assembly thermal transmission coefficient in W/m2/K.

### Uwall

• $${U_{wall}}$$ = The total wall thermal transmission coefficient in W/m2/K.

### Nac

• $${N}$$ = The number of air changes per hour in ach.

### IndoorVolume

• $${V}$$ = The total air volume in building in m3.

### Design Life

• $${t_{des}}$$ = The design life of the building in years.

### Hdd

• $${D_{HDD}}$$ = The heating degree days using the building‘s reference temperature in K days for reference temperature

### Eff

• $${\eta}$$ = The overall heating efficiency.

### EOL Intensity

• $${E_{EoL}}$$ = The energy associated with the end of life phase of a building in J.

## Output

• $${E}$$ = The lifecycle energy usage in a building in J.
• The output is an automatically generated generic response object, which takes the object name of the model plus “Response”.