Life-cycle view

Overview

Life-cycle view works out what in a BimCraft model wears out and is replaced over a study period, such as fifty years. For each part it shows the quantity, the service life, the years of replacement, the cost of each replacement in today's money and its present value. With a carbon result in the model, it can add the embodied carbon of each replacement. The result is a planning table that you can save as CSV.

Who it’s for

• Facilities managers and building owners who plan replacements and budgets.
• Cost planners who need a schedule of replacement costs and their present value.
• Design teams who compare materials by their replacement carbon.

What you can do

• See the parts in the open model that wear out: windows, exterior and interior doors, exterior wall finish, interior paint, floor and ceiling finishes, roof covering, stairs, pipes, ducts, wiring and equipment, each with its quantity and service life (Life-cycle view panel).
• Set the study period, a discount rate and a cost inflation rate, and read the total and its present value.
• Type a cost per unit for any part. Parts with no cost are listed as uncosted.
• See what falls due in each year of the study as a chart.
• Tick Include the embodied carbon of each replacement to add the carbon of each replacement from the Carbon tab's factors.
• Save the schedule as CSV (Save the schedule (CSV)).

Methods and standards

A part is replaced at each multiple of its service life that falls inside the study period. A replacement's cost is inflated at the cost inflation rate (cost × (1 + i) to the power of the year) and discounted at the discount rate to give its present value. Carbon for each replacement comes from the Carbon tab's calculation, divided by quantity for each part's IFC class.

Data and sources

Service lives are built in for each part type, for example windows 30 years, interior doors 40 years and interior wall paint 8 years. They are typical planning figures for the person to review, not a source; real lives depend on product, climate and upkeep. Costs are typed by the person and kept in this browser. Quantities come from the model.

Verification

node bin/test-bimcraft.mjs --lifecycle runs tools/bimcraft-test/lifecycle-test.mjs. It works out replacement years, costs, inflation and present value by hand, then checks the parts of a drawn house and the assistant tool. The repo has no comparison against a reference life-cycle costing.

Limits

Planning figures, not a life-cycle cost analysis under a standard. Only replacements are scheduled: routine maintenance, energy and residual values are not in this view. Wiring length is an estimate from the plan distances between the devices of each circuit. Carbon is only as good as the factors in the model. Service lives and costs are the person's to check.

Files and formats

Reads the open BimCraft model. Writes CSV files (Save the schedule). Lives and costs are kept in this browser and are not saved in the model file.

Get started

1. Open a BimCraft model with walls, doors and windows.
2. Open Life-cycle view in the left panel, under Hazard playback.
3. Set the study period and the rates, type costs per unit, then Save the schedule (CSV).

Languages

No languages are listed for this add-on yet. Its maker may add some.

Works in

Comes with

Nothing else.

Needed by: Facilities and maintenance engineering.

Versions

Licence and maker

CadCraft (CadCraft, first-party). Licence: Apache-2.0. Dependencies carry their own licences, listed on their pages.