Preparing ‘as-built’ drawings and
models is certainly one of the most crucial requirements of any design-build project.
These final set of construction assets validates how the contractor built the
structure including all the changes and modifications that were made in the
process. The finalised drawings and models are passed on from the contractors
to the building owners and property managers.
The set of as-built drawings and
models, though underestimated and neglected, broadly serve a dual purpose.
Firstly, the as-built drawings and models act as a guidebook to the AEC
(architecture, engineering, and construction) firms that are contracted for
renovation and refurbishment of an existing structure. So, the time, cost, and
resources that would have been utilised during pre-renovation survey are saved.
Secondly, they help owners and facilities managers to conveniently undertake
maintenance and refurbishment activities besides helping them during emergency
situations e.g. for rapid evacuation.
Whereas data-rich as-built 3D
building information models have obvious benefits over 2D drawing sets,
the decision to choose one over the other mainly involves factors, such as the
scale of the project, owner’s preference, and the design-build teaming
structure. The owners of relatively small building projects may prefer 2D as-built
drawings of an existing building, prepared by a technician after collecting
accurate data on site. On the contrary, large-scale design-build and renovation
projects may require BIM-driven as-built 3D models.
Assuming that the project in question
has not had a BIM model for the design process which is then updated during the
as-built stage of the project, there are two typical ways of preparing as-built
BIM models. Firstly, using the as-built drawings and other construction drawing
sets as the starting point, 3D BIM models can be prepared
using applications such as Autodesk Revit. The second method involves the Scan
to BIM technique where point cloud data of the structures. This point
cloud data is then converted into an intelligent BIM model using tools such as Cloudworx
and Scan to BIM applications such
as Revit.
The as-built drawings and BIM models
serve as a comprehensive reference tool for owners and property managers. They
benefit from these as-built drawings and models in the following ways:-
·
The finalised
as-built construction assets make future project planning, including
renovations, extensions, and redevelopments, convenient and cost effective for
the owners.
·
Since the as-built
drawings and BIM models contain complete details related to dimensions,
fabrication, erection, elevations, sizing, materials, location, and
mechanical/electrical/plumbing utilities, the owners can use this data and conveniently
manage facilities within budget.
·
The owners can use
these as-built assets to resolve disputes regarding insurance claims. In case
of a massive loss due to extreme disasters, the insurance company will require
extensive documentation, including the as-built drawings and models to support
your claims.
As the as-built drawings and models
are prepared by combining the drawings/models of all the building services, the
owners and property managers can schedule maintenance operations of the building’s
MEP (M&E) systems in a timely manner.
