Page 17 - 14th @ Irving Basis of Design (internal)

critical and that performance would be limited. HVAC efficiency is the single most impactful parameter. If a low-efficiency HVAC system is
selected, the remaining range for improvements is narrow, but if a high-efficiency system is selected, there is a low risk of future decisions
reducing energy savings. Interior lighting and equipment loads can also be used to reduce risk, with the more participation the better. Envelope
parameters appear to be more flexible; this is because the best-performing envelope should be tuned to the load profile, which changes with other
measures. Depending on how they are combined, interior loads and envelope loads either work together to maximize savings, or work against each
other to reduce impacts.

This graph shows the distribution of energy costs among all the combinations studied. All results below the LEED goal include low-efficiency HVAC
systems, a selection that should be avoided to maintain savings. The reach goal is achievable through several pathways incorporating mid- and
high-efficiency selections across all systems. This level of performance can also be achieved without tenant lease requirements through a mid- or
high-tier envelope and high-efficiency HVAC system.

OPPORTUNITIES FOR FUTURE INVESTIGATION
There are a number of additional opportunities which can be investigated as the project continues.

Envelope
— Optimization of facades in response to solar conditions to improve daylight and energy performance, including
— Glazing selections’ thermal insulation, solar heat gain coefficient, and visual light transmittance
— Window-to-wall ratio where flexible
— External and/or internal shading
— Insulation levels for east and west walls

HVAC
— Optimization of economizer controls during the spring and autumn

— Impacts of increased ventilation levels on energy performance
— Fan and pump motor efficiency improvements

Lighting and Interior Equipment
— Target lighting power densities for areas within the C&S scope
— Recommendations for tenants with regards to lighting and daylight control integration
— Alignment with any smart building strategies that may have energy impacts

14th @ IRVING WSP
Project No. B1809809.000
RAL COMPANIES & AFFILIATES Page 17