By Bo Petersson, Director of Engineering Services,
Cornerstone Commissioning Inc.
Too many projects start with high hopes by all parties involved, just to find that once the building is completed, it fails to
meet performance expectations and is harder
to operate than envisioned. This is frustrating
for most team players, but none more than the
owner. This article focuses on the concept of
soft landing and how it can help the successful
transition operation of a building.
WHAT IS SOFT LANDING?
Soft landing for our industry means the transition from construction to owner operation
is more gradual, and all team members of the
close-out process play a role in the transition.
The term originated in Europe, where they have
used this concept for years.
Figure 1 illustrates how the construction
team in general, and the commissioning
authority (CxA) in particular, remain involved
until the operator is completely ready to run
END OF CONSTRUCTION
At the end of the construction phase, the
contractor wants to leave as fast as possible
to ensure a profitable project outcome. For
advanced buildings, the commissioning
team and the MEP contractors often have
months of experience running the building;
and when they leave, all that experience will
leave the site. Owner operators are trained,
of course, but that’s often under compressed
time constraints with significant distractions. They often don’t have a complete
understanding of the design intent and what
aspects of the equipment and controls are of
particular importance. There are often unresolved issues that drag on, which increases
the frustration of the operators. This root
cause of frustration is often a lack of communication between the operators and the
In the end of a construction project, the construction team reduces their presence to a minimum to cut cost. This means that punch list
items and other open issues remain unresolved
for a long time, often creating conflicts between
the owner, design team and construction team.
These conflicts are unnecessary and waste management time. Figure 2 illustrates the process
where, in the end, there are issues that remain
unresolved, often completed with additional
funding by the owner.
With the soft landing concept, the parties are
more involved after substantial completion; and
when properly managed, the issues are resolved
and the parties are aware of when and how to
resolve issues that may take place. Figure 3 illus-
trates this process. However, in the end, there
will still be issues as there’s no such thing as a
perfect building. But compared to Figure 2, the
issues are fewer and the operators have a much
better understanding of how the building is
intended to operate.
DESIGN TEAM ROLE
The design team plays an important role in
the soft landing process. Of utmost importance
is explaining the principle behind the design
and how it was envisioned to operate. They also
must review and participate in resolving open
issues as they are brought to their conclusion.
The design team can explain how they envisioned the building to operate when they performed the energy modeling, and compare the
model to actual results once the building starts
to operate in normal mode. The design also
plays a critical role in solving excessive energy
use situations and can create resolutions.
COMMISSIONING AGENT’S (CXA) ROLE
The CxA plays a major role in the soft landing process. They should have both a good
understanding of the design intent and have
significant operational experience, as they were
involved in the startup and testing of the systems. The CxA sees startup of systems and is
involved in tuning systems to make sure they
operate efficiently. In almost any project, the
amount of open commissioning issues is significant at the substantial completion date. The
soft landing process keeps all parties involved,
and provides a better vehicle to close all open
issues. The process also allows for more organized seasonal testing and deferred testing.
The items above are beneficial for the commissioning process, but the best role for the Cx A
in the soft landing process is assisting the owner
in facility operations as they take over. The Cx A
can help implement design intents and explain
what is important, and what isn’t, to ensure the
building operates efficiently for years to come.
CONSTRUCTION MANAGER’S (CM) ROLE
The CM is another key player in the handover
Making a case for soft landing
Figure 1: Owner and contractor involvement is transitional in a soft landing scenario. Figures: Cornerstone
Figure 2: Issues resolved using traditional approach.