Title
24
Title
24 Energy Code Decisions:
Case Studies
The first step in any project is to establish which
Title 24 standards
apply and which Title 24 compliance requirements must
be met. Once that is done, compliance options can be considered and appropriate
Title 24 documentation prepared.
The following
Title 24 examples present several residential building
scenarios and explain each in the context of
which standards, if any, apply.
Question
A sunspace addition is designed with
no mechanical heating or cooling and a glass sliding
door separating it from all existing conditioned space. Under what conditions
will the Title 24 Standards not apply to this addition?
Answer
The Title 24 Standards do not apply if the space is
unconditioned.
This is the case if:
• The
new space is not provided with heating or cooling (or supply ducts);
• The
new space can be closed off from the existing house with weather-stripped doors; and,
• The
addition is not indirectly conditioned space (see Glossary).
Question
Three stories of residential dwelling
units are planned over a first story that includes retail and
restaurant occupancies. Should the residential apartments comply with the Title
24 Residential Standards?
Answer
No. The residential apartments must
comply with the Nonresidential (High-rise Residential)
Standards since the structure contains four habitable stories and, as a whole structure, is a high-rise building.
Question
A four-story single-family townhouse
has been constructed. Should the townhouse comply
with the Title 24 Residential Standards?
Answer
Yes. As a group R-3 occupancy, the
Residential Standards apply. The building is not an apartment
house (which, according to the UBC, must be at least three dwelling units).
Question
A 1200 sq. ft. manager's residence is
being constructed as part of a new conditioned warehouse
building with 14,000 sq. ft.
Which Title 24 standards apply?
Answer
The whole building can comply with
the Nonresidential Standards, and the residential unit is
not required to comply separately since it is a subordinate occupancy containing
less than 10% of the total conditioned floor
area. However, the residential dwelling
unit must meet all low-rise residential mandatory measures.
Question
Assume the same scenario as in the
previous example, except that the dwelling unit is new
and the remainder of the building is existing. Do the Residential Standards
apply?
Answer
Yes. Since 100% of the addition being
permitted is a low-rise residential occupancy, compliance
under the Residential Standards is required.
Question
An existing duplex is remodeled
without increasing the amount of conditioned space. Do the
Residential Standards apply?
Answer
Even though no new conditioned space
is being created, the remodel must comply with applicable
mandatory measures of the Residential Standards.
Question
A 95 sq ft family room is being added to an existing
2800 sq ft house.
What are the applicable compliance
requirements?
Answer
The addition alone must comply with
the Residential Standards or the existing-plus-addition must
comply. If the prescriptive compliance approach is used for the addition alone, special prescriptive
requirements apply.
Question
A residence is being moved to a
different location. What are the applicable compliance requirements?
Answer
Since this is an existing conditioned
space, the requirements applicable to alterations would
apply to any alterations being made. The building does not need to show compliance with the current energy standards
applicable to new buildings or additions.
Question
A previously conditioned retail space
is remodeled to become a residential dwelling. What
are the applicable compliance requirements?
Answer
The residential dwelling is treated
as if it were previously a residential occupancy. In this case,
the rules that apply to residential alterations are applied.
Question
A 10,000 ft2,
16-unit motel is constructed with an attached 950 ft2 manager's residence. What
are the applicable compliance requirements?
Answer
The manager's unit is less than 10%
of the total floor area, so compliance of the whole building
as the predominant motel occupancy would satisfy the requirements of the standards. Either the entire building must comply with the
Nonresidential
(High-Rise Residential and Hotel/Motel) Standards; or the manager's residence
must comply with the low-rise Residential Standards and the motel occupancy portion of the building must comply with the
Nonresidential Standards.
Question
A subdivision of detached homes
includes several unit types, each of which may be constructed
in any orientation. What are the applicable compliance requirements?
Answer
The low-rise Residential Standards
are applied to each building type. All four cardinal orientations
may be shown to comply or each individual unit in its planned orientation must comply.
Question
A four-story apartment building has
three stories of apartments and a garage on the first floor.
What are the applicable Title 24 compliance requirements?
Answer
For standards compliance, the low-rise Title 24 Residential Standards apply since the building has
fewer than four habitable stories. Note: The UBC considers this a four-story
building. As a high-rise building for compliance with
other building codes, different health and safety regulations apply.
For additional Title
24 information visit the California Energy Commission's website.
back to home page
