Construction Costs - Reference

Reference tab on Construction cost Dialog

 

Data on this tab can be used to enable EnergyPlus to compare the current cost estimate with the results of a previously calculated reference building. It parallels the data on the Adjustments tab but adds a field for entering the cost line item model result for the reference building.

 

All the various adjustments to the project cost estimate are available here as factors that differ between the current and the reference building models to be applied. The factors entered here are applied to the reference building while the factors listed in the Adjustment object are applied to the current building model cost estimate. The results are included in the Construction Cost Estimate Summary table by checking the Component Cost Economics Summary output option.

Note: Reference cost data is used only in EnergyPlus simulations and is not used in DesignBuilder's Cost calculations on the Cost and Carbon tab.

Reference line item costs

This field is used to enter a cost representing the total for the reference building to be compared to the line item cost model for the current building model. A typical source of data for this would be the “Line Item Subtotal” from a previous simulation.

Reference miscellaneous cost per conditioned area

This field can be used to enter a cost model for miscellaneous project costs that are not included in the line item modelling. Miscellaneous costs are entered in cost (local currency) per conditioned floor area. This field allows including the costs of project elements that go beyond what can be modelled using Line item objects. The value input in this field will be multiplied by the conditioned floor area and listed in the Construction Cost Estimate Summary table.

Reference regional adjustment factor

This field can be used to enter an adjustment factor to account for regional differences in construction costs. The factor will be applied to the modelled and miscellaneous construction costs to determine an amount that should be added, or subtracted, to account for local variations in construction costs. The default factor is 1.0, which means no regional adjustment. The additive adjustment is calculated by subtracting 1.0 from the value entered in this field (e.g. 1.05 means a 5% increase).

 

This field is useful for using national average data in the line item and miscellaneous construction cost models and then altering the results based on regional differences.

 

The total base costs calculated by applying regional adjustment factor to modelled and miscellaneous construction costs will be used for calculating other additional costs in terms of multiplying the fractions in the following five fields.

Reference design and engineering fees

This field can be used to enter a fraction of total base costs that should be added to account for design and engineering fees. Note that it is not the same as a fraction of the total cost estimate.

Reference contractor fee

This field can be used to enter a fraction of total base costs that should be added to account for Contractor fees. Note that it is not the same as a fraction of the total cost estimate.

Reference contingency

This field can be used to enter a fraction of total base costs that should be added for contingency. Note that it is not the same as a fraction of the total cost estimate.

Reference permits, bonding and insurance

This field can be used to enter a fraction of total base costs that should be added to account for permitting, bonding, and insurance costs to the project. Note that it is not the same as a fraction of the total cost estimate.

Reference commissioning fee

This field can be used to enter a fraction of total base costs that should be added to account for commissioning services. Note that it is not the same as a fraction of the total cost estimate.