# Service Life Prediction and Life Cycle Costs of Light Weight Partitions
## 5 Life Cycle Cost Analysis
### Lifecycle Cost Analysis in Standard Service Conditions  
The analysis is based on calculating life cycle costs and the predicted service life of the three types of partitions in different service conditions, as in the Section 4 analysis. \[NPV=C+R\times sr(i,lc)\times rp(i,k\times lc)+(M+O+T+A)rp(i,LC)-S\times sp(i, LC) \tag{7}\]  
where,  
C--Initial Investment: The upfront cost required to purchase and install the partition or building component. R--Replacement Cost: The cost of replacing the component at the end of its service life. M Annual Maintenance Cost: The yearly cost incurred to maintain the partition or building component. O--Annual Operating Costs: Yearly costs associated with the operation of the component or system. T--Taxes: Any tax-related expenses associated with the component over its lifecycle. A--An Ancillary Costs: Additional costs that might not fall directly under other categories. S--Salvage Value: The residual value of the component at the end of its service life. LC--Planned Lifecycle of the Building: The overall expected duration the building is planned to last. lc--Life cycle of Building Component: The expected or average service life of the building component. i--Annual Interest Rate: The rate of interest used to discount future costs and benefits. k--Number of Lifecycle Repeats for Component: The number of times the component goes through its lifecycle. rp(i,n)--Present Value Coefficient of an Annuity: A factor used to calculate the present value of a series of payments. sr(i,n)--Sinking Fund Factor: A factor used to convert a future value sum into a series of equal present value payments. sp(i,n)--Single Present Value Factor: A factor used to determine the present value of a single future amount. The lifecycle cost analysis was divided into four categories of negative occupancy factors (u), as previously described. Several assumptions were also made:  
* LC (Planned Lifecycle of the Building): The building is planned to last for 50 years. * Annual Interest Rate (i): 5% per annum. * Operating costs, taxes, ancillary costs, and salvage value: Assumed to be zero. * Initial Construction Costs:  
* Hollow concrete block partition: 154.8 ILS/m2
* Autoclaved aerated concrete block partition: 131.3 ILS/m2
* Gypsum board partition: 94.2 ILS/m2
* Replacement costs:\(\bigcirc\) Hollow concrete block: 185.8 ILS/m\({}^{2}\)  
\(\bigcirc\) Autoclaved aerated concrete block: 157.6 ILS/m\({}^{2}\)  
\(\bigcirc\) Gypsum board: 152.7 ILS/m\({}^{2}\) (including disassembly of the old partition)  
* Annual maintenance costs (M): Established as customary at 0.5% of the asset value for all types of partitions examined in the study. * Partition lifecycle (lc): Based on the service life expectancy and performance range predicted in standard deterioration conditions, as determined. * Component replacement: A component is only replaced if its residual life is more than half of its standard predicted lifecycle in given conditions (for instance, if the standard service life of a component is 40 years and the planned lifespan of the building is 50 years, the component will not be replaced in year 40 because its residual life of 10 years is not greater than half of its standard predicted service life). Table 12 and Figure 15 provide a breakdown of the lifecycle costs and expected service life of partitions (made of gypsum board, autoclaved aerated concrete blocks, and hollow concrete blocks) in various service conditions. On the basis of the analysis, the following key findings and conclusions (related to the lifecycle costs of partitions in varying occupancy conditions) have been established:  
1. Gypsum board partitions exhibit the lowest initial cost, while hollow concrete block partitions demand the highest investment. Comparison of the implementation of aerated concrete block partitions and hollow concrete block partitions shows the former costs approximately 15% less. 2.