J
Building Performance and Testing
A multifamily project that requires a PERF-1 form may find it difficult to meet the minimum threshold of X % above the CEC requirements. Some adjustments and considerations that could help the project meet this threshold are as follows:
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High-Rise: The PERF-1 form uses equivalent default values for lighting, receptacle loads, and process loads for both the standard and proposed energy budgets. By including these default values, the net energy use( in kBTU per square foot) is different than what is warranted by the CEC for low-rise residential dwelling units. The lighting, receptacle, and process loads should be eliminated from the compliance margin calculation for high-rise buildings by manually subtracting them from the standard and proposed numbers and generating a compliance margin. This adjustment results in an“ apples to apples” comparison with low-rise residential buildings, where lighting and receptacle loads are not included in the compliance calculations. This adjustment is consistent with procedures for utility rebate programs. Corridors: According to CEC requirements, a high rise residential building with a total area used for non-residential occupancy of more than 20 % requires the model to distinguish non-residential and residential units. It is necessary to assess whether or not the corridors need to be calculated in the compliance calculations.
The corridors can be considered unconditioned or not indirectly conditioned if all of the following conditions apply:
– The corridors are tempered with less than ten Btus per square foot of heating. – The corridors are tempered with less than five Btus per square foot of cooling. – The doors to all units are weather-stripped. – The shared wall between the corridors and all units are insulated.
These elements create a thermal break between the corridors and the units, creating unconditioned space. Therefore, the conditioned space of the units is not indirectly affecting the corridors, and the corridors themselves are not conditioned. If the corridors do not meet all of the listed conditions, the corridors are considered to be conditioned, and therefore must meet nonresidential standards unless they fall under the 20 % rule. If more than one CEC report is available for the residential portions of the project, use the worst case scenario for the rating.
J5.2. Non-Residential Spaces Outperform Title 24( up to X Points) Note: This measure is available for multifamily projects only.
One point will be awarded for every 1 % that the project outperforms the CEC recommendations, based on a weighted average of the square footage of the non-residential area. If more than one Title 24 report is available for the non-residential portions of the project, use the worst case scenario for the rating.
DRAFT
This measure applies to non-residential ancillary spaces only. This measure is typically only applicable on projects where more than 20 % of the conditioned floor area is dedicated to non-residential units. A Title 24 report will show the percentage above code for the residential and non-residential portions of the building( s) on the PERF-1 form. The report must include the actual building components and HVAC systems included in the final building design( that is, a simulation is run based on plans at least at the 100 % Construction Documents phase). Plug and Process loads should not be removed for this measure.
The project does need to meet the criteria presented in measure J5.1 to qualify for this measure.
Note that the Title 24 standards and reports are currently based on projected Time Dependent Valuation( TDV) energy use, which is also the basis for the GreenPoint Rated program. The Rater should also request the non-TDV reports ECON-1 and ECON-2 for energy use inputs for the climate calculator.
DRAFT GreenPoint Rated New Home Rating Manual 68 Version 6.0, September 2013
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