For any construction project, several estimates can be prepared during the planning phase to ensure stakeholders have a clear understanding of the projected scope, cost and timeline. In general, initial estimates are intended to be created quickly and economically. As planning proceeds and the project nears kickoff, there comes a need for more accurate and more time-intensive estimate types.
So far, we’ve discussed when to use conceptual estimates and square foot estimates. Conceptual estimates are great for quickly assessing the feasibility of a project, and square foot estimates can help project owners quickly understand how different design options may affect the final cost per square foot.
For projects that are approaching the final phases of design, the most appropriate type of cost estimate to create might be a systems and assemblies estimate. In this blog post we’ll learn more about what systems and assemblies estimates are, and how they can help you plan the details of your projects and get a more accurate idea of what your projects might cost.
What is a Systems and Assemblies Estimate?
Simply put, a systems and assemblies estimate breaks down a project into its major components like roofs, walls, electrical systems and HVAC systems. Each system or assembly is comprised of a group of line items or parts that are necessary to build that component. At this point, the details of each system or assembly can be considered in more detail than previous estimate types.
Systems and assemblies estimates paint a more accurate picture of what a project might cost than conceptual or square foot estimates because they account for materials and labor with more granularity. For example, while a square foot estimate might predict a building’s cost by assuming the cost of building walls per square foot and scaling that number, a systems and assemblies estimate will account for the actual linear feet of walls needed. This allows for each system and assembly to be scaled independently, by their respective units. A good systems and assemblies estimate can predict final cost within 10-15% accuracy.
Read more about how different estimate types are used at various stages of project planning.
More Specific, More Accurate Budgets
A major benefit of this estimate type is its ability to help decide between multiple specifications for each system or assembly. For example, if a project owner is considering upgrading a standard shingle roof to an environmentally-friendly one, an estimator can quickly create a separate roof assembly that includes all the specific materials and labor costs required. The project owner can then see the cost difference between the two options and decide if going with a green roof is worthwhile. For that reason, systems and assemblies estimates can be a great budgeting tool.
Another benefit of a systems and assemblies estimate is that it can help keep track of all the different parts that come together to make up each component. This makes it easy for estimators to make sure everything is adding up correctly. It also helps estimators transparently show project owners how each material choice impacts final cost. Breaking down a building into specific assemblies helps to ensure all parts and processes are accounted for.
Better Data Makes Better Estimates
Because systems and assemblies estimates are created to get an accurate idea of a project’s total cost, having access to accurate cost data has never been more important. With Gordian’s RSMeans Data Online, estimators can instantly access dozens of pre-built assembly models from anywhere, at any time. And each of these are up-to-date with accurate, localized costs backed by over 30,000 hours of research to help estimators create better systems and assembly estimates, more efficiently.
