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— Multifamily Properties Quarterly — July 2015
First, builders will have to deliver
more units to flood the market with
supply. If they are able to deliver
enough units to match continu-
ing demand and make up for the
shortfall of 80,000 units, then prices
should flatten. But the big question
is: Can that be done? And if it can,
when? The biggest year of single-
family deliveries over the period we
studied was 2004 when 18,000 units
were delivered, which is 10,000
units more than we saw delivered
in 2014. Therefore, we have a long
way to go to make up for the short-
fall, and rising construction costs
are making building moderately
priced housing more and more dif-
ficult to meet this demand.
Second, a lack of sufficient high-
paying jobs to provide salaries for
people to afford the newly con-
structed apartments and single-
family homes would slow the mar-
ket. But with Denver’s diversified
economy and continued desirability
of our area, that seems unlikely.
Even the current oil bust won’t sig-
nificantly impact jobs, as oil jobs
are only a relatively small part of
our overall economy. In fact, accord-
ing to recent data, job growth is
exceeding population growth, which
will only drive salaries higher.
Third, even if there are sufficient
jobs to support new construction,
where will the lower and lower-
middle class live? Currently, these
classes are moving to the suburbs
to occupy 1970s product. But with
annual rent growth of 13 percent for
this product, vacancy in the low 4
percent range, and investors rehab-
bing older product for value-added
upside, lower- and middle-class
workers will struggle to pay rent
even in these areas.
There certainly are a host of
unknown factors not mentioned
above that could undermine the
population and economic growth
that Denver is experiencing – think
dot-com bust or derivatives in
mortgage-backed securities. How-
ever, after every recession, Denver’s
economy has come back bigger,
stronger and more diverse. Addi-
tionally, people not only move to
Denver for jobs, but also it is one
of the most popular places to live
in our country due to the quality
of life, great outdoors, recreation,
entertainment and dining. Our
long-term view is that Denver will
continue to attract new residents
and employers for these reasons.
While we certainly miss the old
Denver without traffic and parking
problems, we really enjoy all that
the new Denver has to offer!
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Improve
up to 40-foot-long spans, which
increase interior space.
The hollow-core members offer
a distinct advantage over other
traditional slab building materials
because of the speed of produc-
tion and installation. No shoring
is required for the slabs, allowing
for 4,000 to 10,000 square feet of
installation daily. Hollow core can
be used as a lateral load diaphragm
to support multiple floor and wall
loads and, because it requires less
concrete and steel reinforcement,
it results in less job site conges-
tion than normal building methods.
Structurally, a hollow-core system
provides high-load capacity for
floors, open clear spans, high-vibra-
tion resistance, finished ceilings and
floors, and reduced floor-to-floor
heights.
Unique wrap structures feature
multiple levels of parking, which are
surrounded by multifamily housing
units. The structures are intended to
incorporate spacious interior areas
and blend into surrounding struc-
tures. In this type of project, the
parking garage system is the first
stage completed. Living quarters
are then erected around the parking
structure. Precast often is selected
for wrap projects to meet installa-
tion requirements and enhance con-
struction efficiency on limited area
construction sites.
In an effort to reduce construction
and trade overlap, precast park-
ing structures are available with a
pretopped option. The high-quality
concrete required for topping is
installed in the plant concurrently
with the floor member as one
monolithic piece. This reduces top-
ping required in the field, which
reduces the weather’s impact during
topping placement and the detri-
mental effects of a poor cast-in-
place job.
Precast framing components for
wrap projects include double tees,
beams, columns, spandrels, T-beams
and wall panels. Structural and load-
bearing exterior panels are designed
as a structural load-bearing archi-
tectural envelope, reducing the need
for additional framing members.
The precast components used in
wrap structures provide lateral
restraint and gravity load support,
while meeting fire separation code
requirements between living units
and parking.
As Colorado’s housing market con-
tinues to proliferate, prefabricated
precast products will continue to
offer a viable solution to expedite
the building process. Precast inher-
ently provides efficiency, resiliency,
versatility, durability and aesthetic
advantages needed to meet structur-
al and architectural requirements of
this ever-growing market segment.
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airborne sounds. Most projects can-
not be constructed economically
with solid masonry or concrete
demising walls. Most projects are
constructed out of lighter wood-
framed partitions and floor/ceiling
assemblies. While the lighter assem-
blies do a better job of attenuating
higher-frequencies sound verses
lower-frequencies sound, it is the
mass of the materials used and the
isolation of materials to one another
that really make the difference.
In wood-framed partition con-
struction, methods that separate
the layers of materials can reduce
both airborne- and impact-sound
transmission. The common demis-
ing and corridor partitions are best
constructed using staggered stud
spacing on sill plates that are set
in sealant on the subfloor. Gyp-
sum board should not be attached
directly to the studs, but installed
on resilient metal channels on at
least one side of the stud framing.
This isolation reduces the sound
transmission through the structural
frame. A second layer of gypsum
board can increase the STC rating
of the partition by about 9 dB. Fill-
ing at least two-thirds of the cavity
with absorptive insulating material
increases sound transmission by 8
to 10 dB, if properly isolated. The
perimeter of the wall and any pene-
tration must be sealed airtight with
a nonhardening acoustic sealant.
In wood floor/ceiling construction,
methods and details that attenuate
sound are similar to that of parti-
tions. This includes heavy material
layers that are not solidly attached
to the framing members and sepa-
rated by a thick cavity that is filled
with absorbing insulation.
To achieve the minimum STC rat-
ing, the ceiling material of the floor/
ceiling assembly should be a double
layer of gypsum board attached to
resilient channels. The cavity should
contain sound absorbing insulation.
Adding 1½ inches of concrete aids
in increasing the STC ratings by
effectively attenuating the high-fre-
quency airborne noises, but it does
little to attenuate the IIC ratings
low-frequency noises for the floor/
ceiling assembly.
The addition of a “floating floor”
system is one way of attenuating
the lower-frequency noise. This sys-
tem requires an isolation layer of
a resilient cushion or interlayer of
foamed rubber, plastic mesh or cork
between the wooded subfloor and
the concrete mass. Ceramic tile and
hardwood flooring will reduce the
IIC rating over resilient flooring or
carpet and pad.
The majority of noise concerns
also can be alleviated through
proper space planning. Quiet areas
should not be located near poten-
tially noisy areas. If you can mirror
uses and spaces back to back along
a demising partition then the rela-
tive background noise of each space
helps dampen the sound generated
within adjacent spaces. Potentially
annoying sound transmission from
floor to floor can be attenuated
through the vertical stacking of uses
and spaces.
Since one of the biggest concerns
with occupants of multifamily liv-
ing units is noise from adjoining
units, good sound-attention design
can greatly affect the value of these
projects.
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Courtesy: Colliers International
