BIM Based Quantity Take-off, Estimating and Scheduling

2010-12-15  johnan
BIM Based Quantity Take-off, Estimating  
and Scheduling 
This white paper describes the basic concepts and the process of BIM based 
quantity take-off, estimating and scheduling.Each software vendor have their 
own terminology, but our principles should be generic. The paper also describes Tocoman’s solution for BIM based estimating and scheduling.   
 
Basic Concepts 
Building information model (BIM) 
contains information about the design of a building. Such a model 
consists of object types (e.g. spaces) and their properties (e.g. name, 
number and area). The BIMs may 
be created either by designers or 
by the construction company from 
the 2D drawings produced by the 
designers. The latter option is typically seen as a temporary solution 
while designers are adopting BIM. 
Construction recipes describe a 
building from the construction point 
of view – as building elements and 
components (or activities) required 
making them (see figure 1). 
  
 
Figure 1 – Construction recipe. 
Building elements and components 
are typically classified by system 
and trade. This enables to query 
the information in a flexible way, 
e.g. concrete works (trade) in the 
foundations (system).   
Process 
The properties of BIM objects cannot be used directly for cost estimating or scheduling in most cases. Foundations objects, which are 
different from the design point of 
view, might be grouped together 
because they will be built using the 
same production method. Single 
space, on the other hand, could 
produce quantity information for 
multiple cost estimating items, like 
surface materials, equipment and 
furniture. Thus construction quantities need to be calculated from the 
design quantities in BIM.   
The quantity take-off is done by 
linking the design quantities with 
recipes. The result is component 
quantities, which can be used e.g. 
for cost estimating and scheduling 
(see figure 2). 
 
 
Figure 2 – Process for BIM based
cost estimating and scheduling. 
 
The cost estimating and scheduling 
happens by applying unit cost and 
production rate information into the 
BIM based quantities (see figure 2). 
F 12 EW- 1 Wall, concrete, 300mm M2
F 12 1100 Finishing M2
F 12 2200 Concrete M3
F 12 2510 Reinforcement KG
Building
Element
Components
Construction Quantities
(component quantities)
Design Quantities
(object quantities)
Estimate
Schedule
Production
Rates
Unit
Costs
Construction 
Recipes
Design
BIM 
Copyright © 2010 TocoSoft Oy. All rights reserved. 
Tocoman’s Solution 
Tocoman has developed a suite of 
applications bridging the gap between current BIM applications and 
existing cost estimating and scheduling applications. The Tocoman 
solution contains two applications 
(see figure 3).
 
 
Figure 2 – Tocoman BIM solution.
Tocoman iLink for calculating 
the quantities from various BIMs 
and linking them with recipes. 
 
Tocoman Express for integration with various estimating and 
scheduling applications. The application enables to read the recipes from a cost estimating application and write BIM quantities 
back into the estimate of various 
scheduling applications. 
 
Tocoman’s solution is implemented 
in a way, which decouples end user’s choice of BIM application from 
the choice of the cost estimating 
and/or scheduling application. Any 
supported BIM application can provide quantities for any estimating 
and/or scheduling application. 
Tocoman also uses intelligent linking technology, which minimizes 
the requirements for the building 
model’s content. The solution does 
not require using certain BIM object 
properties e.g. for identifiying wall 
types.Instead the user can select, 
which property he wants to use.  
Tocoman’s requirements for building models, which are used for BIM 
based quantity take-off, are generic 
by nature. 
Must be consistent 
 
All building model contents must 
be modeled as agreed between 
the project team. 
Must be identifiable 
It must be possible to identify all 
objects from the viewpoint of 
quantity take-off. The exact BIM 
object and property is not relevant, if it is consistently used. 
 
Must be measurable 
All building model content must 
be modeled using objects, which 
offer the required information for 
quantity take-off. Modeling walls 
e.g. using a generic mass object 
is not recommended, if the BIM 
application has a native wall tool. 

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