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COLORADO REAL ESTATE JOURNAL
— April 20-May 3, 2016
“My best friends are PHCC
members. I can call them
on weekends, or evenings,
and say, ‘Hey, I have this
going on… what do you
think? They’ll tell me,
‘Why don’t you try this?’
I’m sure to get an honest
response.”
303-757-3956
Experts
Pursuing
Excellence
130
YEARS OF
INNOVATION
MORE THAN
Construction, Design & Engineering
W
ith all the multiresi-
dential apartments,
condominiums and
townhomes being built, one of
the biggest acoustical design chal-
lenges is impact sound isolation.
The trend or desire to use thinner
and lighter construction materials
often result in complaints from
the resident. On top of it, the
national standards that apply do
not account for low frequencies
or people’s satisfaction. From our
work on many of these projects,
we know the International Build-
ing Code Sound Transmission
Class and Impact Isolation Class
minimum required rating of 50
does not provide the privacy that
most people desire. This may be
connected to the fact that you can
hear low-frequency impact noises
or “thumps.”
The typeof structureuseddirect-
ly affects the level of sound isola-
tion that can be achieved. Wood
structures are lighter than steel
or concrete. They are not as stiff,
so when your neighbor is doing
jumping jacks over your head,
youmay not hear his voice, which
is in the mid- to high-frequency
range (500 hertz to 8,000 hertz) but
you can hear the low-frequency
(31.5 Hz to 125 Hz) impacts. The
light structure gives and transfers
the energy to the space below. To
add to the challenge, fitness spaces
are included as an amenity for the
residences but they are located
above the units.
Here’s the rub.
ASTM standard-
ized tests for Impact Isolation
Class require the use of a spe-
cial tapping
machine and
include testing
for frequencies
between 125
Hz to 4,000
Hz. The tap-
ping machine
is not effective
in generating
impact noise
at frequencies
lower
than
125 Hz. The
hammers of
a standardized tapping machine
that impact the floor surface
weigh a little over a pound each
are dropped a height of a little
more than 1½ inches. While this
provides a standard method to
compare the assemblies, it does
not mimic the impact of a person
walking in hard-sole shoes. This
means you can test and pass a
floor-ceiling assembly as compli-
ant with the requirements but the
occupants can still hear low-fre-
quency impacts, thuds or thumps
from footfall. Unfortunately, the
Impact Isolation Class ratings for
what are considered to be low-,
medium- and high-quality apart-
ments or condominiums are not
in sync with people’s satisfaction –
most notably for wood structures.
To address this issue, the struc-
ture needs to be stiffer and mass
added to the floor-ceiling assem-
bly. This is why we review the
octave-band transmission loss
at the frequencies below 125 Hz
when comparing the acoustical
performance of assemblies. We
alsohave conductednonstandard-
ized tests dropping larger objects
like a medicine ball to measure
the low-frequency impact isola-
tion. Bottom line, reducing low-
frequency impact noise is very
challenging, particularly in wood
structures.
There is no silver bullet (i.e.,
the paper-thin underlayment that
allegedly increases the impact iso-
lationby25points ormore).Carpet
and padused to provide good lev-
els of impact isolation but are now
being replaced by wood, tile and
vinyl toppings. For this reason, it is
now more important than ever to
provide structural stiffness and a
decoupledmass layering to isolate
residences from each other and
reduce that thump, thump, thump
in the middle of the night.
s
Ed Logsdon
Associate principal,
D.L Adams Associates,
Denver
L
ighting can account for
25 percent of all util-
ity usage for building
owners and operators today.
Upgrading traditional systems
to more energy-efficient lighting
can not only help reduce energy
consumption but also provide
a significant costs savings on
a daily basis. Whether you are
upgrading lighting at an existing
space or building new construc-
tion, moving to LED lighting is a
smart way to save, operate more
efficiently, reduce the impact on
the environment and increase
your investment in human capi-
tal.
Energy-efficient
lighting
upgrades carry an average return
on investment of 45 percent, typi-
cally representing the single-big-
gest return possible on a single
project, and easily justify their
upfront cost. In existing build-
ings, lighting systems can be eas-
ily retrofitted to accommodate
modern LED lighting with an
upfront investment and cost sav-
ings throughout the building’s life
cycle. Retrofitting takes advantage
of existing electrical components
and infrastructure, and can help
improve building safety. As ret-
rofits lower the electrical load in
a building, there is less strain on
air-conditioning, ventilation and
refrigeration systems, reducing
the occurrence of blown outlets or
overheated fuses.
D e v e l o p -
ing an over-
all lighting
and efficiency
plan for a
commercial
space is key
when mod-
ernizing to
LED systems.
C o n s i d e r
incorpora t -
ing dimmers,
timers and
motion-acti-
vated sensors
to reduce energy usage when
certain spaces are not occupied.
These intelligent additions can
significantly lower monthly
energy bills and contribute to
an overall reduction in building
energy use. Creating a custom
lighting plan for each room or
area of a building can dramati-
cally increase occupant com-
fort and productivity. Updated
lighting systems now include
reduced flicker, increased light
output and improved color and
consistency, all of which have
been proven to positively impact
occupant satisfaction levels.
While any significant lighting
project will carry an initial price
tag, new lighting technologies
typically pay for themselves in
energy savings within the first
few years (and through certain
LED lighting companies, imme-
diately). For business owners,
operators and developers who
don’t want to assume a large
cash expenditure in this area,
financing new lighting systems
has become an increasingly pop-
ular option due to specialized
rates and flexible leasing terms
available.
Lighting retrofits are common-
ly eligible for numerous state
and federal utility rebates and
tax incentives offered to sustain-
able lighting projects for nonresi-
dential buildings. Sustainability
programs provide incentives to
commercial property owners
using qualifying energy-efficient
Alex Gish
Director of business
development,
Dynamic Funding Inc.,
Englewood
