Written by Judhajit Chakraborty, Assoc. AIA, LEED, AP, WSP Built Ecology
July 1st — Mark Your Calendars
By the time this gets published, there will be only about two weeks left for the new Title-24 2013 codes to be in effect. I know most of our readers must have been a part of at least one seminar/webinar outlining the changes in
the new code, especially the energy code which includes changes/improvements in building envelope, lighting, HVAC changes, new commissioning requirements and many more. All these changes make the new code about 25% more energy efficient than the 2008 code and closer to the hidden goal of zero net energy for all new residential construction by 2020 and all commercial construction by 2030.
But it will also trigger a rise in projects’ first costs. For example, with all the new lighting controls, the costs are likely to go up by a margin of 20%-30% for just lighting only. More stringent codes also mean more time for design and analysis. So it means, in California, even for a code compliant building, architects may have to ask for more fees than it used to be with the older code. Food for thought!
Below are some salient changes in LOW RISE RESIDENTIAL ENERGY CODES:
Prescriptive Measures – They can be traded off using a performance method for compliance (Energy Model)
• Window U-Factors, now down to 0.32 and Relative SHGC down to 0.25 in most climate zones.
• Maximum fenestration U-factor (assembly with frames) – 0.58 (can average across entire home)
• Ceiling insulation increased to R-38 (zones 1, 11-16)
• Vapor Barrier on walls in climate zones 14 and 16.
• Duct Insulation minimum R-values have been raised from R-4.2 to R-6 in climate zones 6, 7, and 8.
• Whole house fan is now required to be installed in climate zones 8-14; allowing a minimum of
2cfm/ft² of floor area.
• Radiant Barrier requirements expanded to climate zones 3, and 5-7.
• Wall insulation increased to R15 (cavity) + R4 (continuous) or R13 (Cavity) + R5 (Continuous)
in all climate zones.
• HERS verification has now been expanded to include ducted packaged units, mini-splits, and
Mandatory Requirements – They are a must and cannot be traded off with the performance method.
• HERS verified onsite duct sealing and leakage testing in all climate zones unless ducts are in conditioned
• Return ducts are now mandatory. Exception, have HERS test for 350cfm/ton minimum airflow.
• Lighting – Require at least one high efficacy luminaire in each bathroom.
• All hot water pipes ¾” or larger to be insulated.
• Solar Ready Measure – 250 square feet of solar ready zone on single family roofs in subdivisions
of 10 or more homes.
• Minimum 15% of the roof area in multifamily homes has to be solar ready.
• Mandatory maximum fenestration assembly (including frame) U-factor of 0.58
• HERS verification required for whole house IAQ fans. ■