Choosing the right metrics when designing buildings is critical. A good energy modeler knows how to navigate metrics and provide clients with the insights they need. From a design consulting practitioners perspective.
2. Example Large Project
GOALS: LEED, Title 24 2013 (?), Energy Efficiency, and an on-going
owners project requirements (OPR) of additional goals
MEP DESIGN: Radiant-cooling w/ VAV, waterside economizer and
heat recovery
In a rush to make a plan for measurement and verification, the owner
team is asking to use Title 24 during the M&V process.
Concept SD DD/CD Permits
Occupancy
M&V
EUI / LEED
Title 24?
EUI / ASHRAE 90.1?Modeler
Client
3. Example Small Project
• Multiple building school project
• Scope and fee for code-compliant
modeling
• Originally, no plan to model
extensively during schematic phase
• During design development, client
now asks to explore envelope
assemblies
• We only had EnergyPro T-24 model
• Client asked for T-24 results to
inform envelope decisions
• Mechanical design has no cooling
4. Rough Results (not issued)
• Results show almost
no change in any
measure
• Most savings are
heating (gas) and are
not important to T-24
• Model not intended
for performance
modeling
• Confusing results that
we ultimately did not
show to client
5. What we really want to talk about
• All metrics are not created equal
• The benefits of better metrics
• How do we choose better metrics?
(by project phase and deliverable)
• How do we (as a community) implement
better metrics
6. Energy Metrics for Buildings
T24
LEED pts
Energy Star
ASHRAE 90.1
Energy Cost
Predicted EUI
Measured EUI
7. Picking an Energy Metric
Most decisions are not
actually made! Decisions
tend to fall to whatever the
default condition is.
Our experience has
found most clients will
pick T24 in California.
8. Making a choice takes effort, whereas sticking
with the default is effortless. Another reason
is when decisions have unclear costs and
benefits that are difficult to evaluate, defaults
can imply the “recommended” option, thus
saving people the time of thinking through the
choice themselves.
Behavioral Economics
9. Benefits of Better Metrics
• Capturing New Technologies
• Making Design Decisions
• Useful in Multiple Project Phases
• Streamlined Process
• Same language as other Prof Orgs (like AIA)
16. Multiple Goals - Multiple Metrics
LEED
Net Zero
Code
Compliance
EUI
Metric
T24
LEED pts
Energy Star
ASHRAE 90.1
Energy Cost
Predicted EUI
Measured EUI
Arch 2030
T24
Goals
Code Compliance
LEED pts
Design Performance
Savings by Design
Net Zero
Arch 2030
LEED pts
17. Risk of a Metric
• Metric becomes obsolete in project lifetime
• Metric does not provide enough granularity
• Complexity of baseline
• Metric does not address goal (ex: LEED
req'd cooling negatively impact nat vent
project)
• Metric does not address current technology
• Metric skews results in favor/against project
18. Opportunity of a Metric
• Code Compliance
• Capturing New Technologies
• Green Certification
• Useful in making design decisions
• Ability to hold metric through multiple phases
(longevity)
• Streamlined process
• Same language as other prof. Orgs (like AIA)
19. Title 24
Code
Compliance
Capturing New
Technologies
Green
Certification
Making Design
Decisions
Useful in
Multiple Project
Phases
Streamlined
Process
Same
language as
other Prof Orgs
Opportunities
Risks
Metric Becomes
Obsolete
Doesn't Provide
Enough
Granularity
Complexity of
Baseline
Doesn't Address
Goal
Doesn't Address
Current Tech
Skews Results
(better or worse)
20. LEED
Risks
Metric Becomes
Obsolete
Doesn't Provide
Enough
Granularity
Complexity of
Baseline
Doesn't Address
Goal
Doesn't Address
Current Tech
Skews Results
(better or worse)
Code
Compliance
Capturing New
Technologies
Green
Certification
Making Design
Decisions
Useful in
Multiple Project
Phases
Streamlined
Process
Same
language as
other Prof Orgs
Opportunities
21. EUI
Risks
Metric Becomes
Obsolete
Doesn't Provide
Enough
Granularity
Complexity of
Baseline
Doesn't Address
Goal
Doesn't Address
Current Tech
Skews Results
(better or worse)
Code
Compliance
Capturing New
Technologies
Green
Certification
Making Design
Decisions
Useful in
Multiple Project
Phases
Streamlined
Process
Same
language as
other Prof Orgs
Opportunities
25. How do we implement better
metrics?
Where do you see opportunities to do this?
How do we choose better metrics?
(by project phase and deliverable)
How do we (as a community) implement better
metrics?
(show graph) (Add that there was DX baseline cooling for half the spaces, skewing the results)
Results show almost no change in any measure which are mostly due to savings in heating (gas) and on a Title 24 scale does not really register. Even though many of these improvements will increase the comfort and performance of the building, the model built was created for code-submission and the metric was designed for pass/fail results. This resulted in a confusing set of answers and ultimately we did not present these to the client.
The opportunity to quantify the value of these ideas needs support and fee but also needs a better metric to tell a straight-forward story. Opportunity is to give feedback in a rational way instead of wasting time calculating and explaining Title 24.