# Presentation: 690441

## Building Envelope Provisions

*Stephen V. Skalko, PE*
*Portland Cement Association*
*Past Chair, ASHRAE SSPC 90.1 **Envelope Subcommittee*

## Section 5.1.1 Scope

**Building envelope applies to **
**Conditioned spaces separated from **
**the exterior, **
**semiheated spaces and **
**unconditioned spaces**
** ****Conditioned spaces are:**
**Cooled by systems with a sensible output capacity greater than 5 Btu/h•ft****2 ****of floor area**
**Heated by systems with output capacity relative to floor area that is greater than or equal to the criteria in Table 3.2**

## Section 5.1.1 Scope

**Semiheated spaces are those heated by a system whose input capacity is greater than or equal to 3.4 Btu/h•ft****2**** of floor area **_**but is not a conditioned space**_
**Unconditioned spaces are enclosed spaces within a building that are not conditioned or semiheated**

## Section 5.1

- Spaces in climates that exceed 1800 HDD65 shall be assumed to be conditioned spaces unless
- the space will only be semiheated or unconditioned _and_
- if approved by the Building Official

## Section 5.1.2 Compliance Requirements

**5.1 General Provisions **_**and**_
**5.2 Mandatory Provisions **_**and**_

**5.3 Prescriptive Building**
**  ****Envelope Option **_**or**_** **

**5.4 Building Envelope**
**Trade-off Option **

## Section 5.1.3 Climate

**Based on CDD50 and HDD65**
**Appendix D**
**Unlisted locations**

## Criteria Tables - App B

- 			      _**90.1 - 1989**_	     _**90.1 - 1999**_
**Number****	****	****   38****	****	****            26**
**Variables****	****HDD50****	****	****HDD65**
**	****	****	****	****CDD65****	****	****CDD50**
**	****	****	****	****VSEW**
**	****	****	****	****CDH80**
**	****	****	****	****HDD65**

## Climate Data

-             _**90.1-1989**_**    **_**90.1-1999**_**    **_**ENVSTD**_
**U.S.****	****	**** 234****	****	****    650****	****       4790**
**Canada****	**** 116****	****	****      86****	****       1217**
**Int’l.****	****	**** **_**    0**_**	****	****    **_**140**_**	****       **_**      0**_
**TOTAL****	**** 350****	****	****    876****	****       6007**

## Section 5.2 Mandatory Provisions

**5.2.1 Insulation**
**Installed in accordance with the manufacturers recommendations**
**Installed in substantial contact with the inside surface of the building envelope unless using reflective surfaces for performance**
**Recessed equipment does not affect insulation thickness**
**Exterior insulation protected from damage**

## Section 5.2.2 Fenestration and Door Products

**U-factors **
**NFRC 100 or **
**Assemblies listed in Appendix A**
**Solar Heat Gain Coefficients (SHGC)**
**NFRC 200 or**
**Assemblies listed in Appendix A**
**Visible light transmittance (VLT)**
**NFRC 200 when the trade-off option is used**

## Section 5.2.3 Air Leakage

**Sealing of openings and joints in the building envelope**
**Fenestration and doors per NFRC 400**
**Loading docks in climates over 3600 HDD**
**Vestibules for doors separating conditioned space from the exterior**

## Section 5.2.3 Air Leakage Exceptions

**Buildings**
**in climates less than 1800 HDD65**
**less than 4 stories**
**Non-building entrance doors**

## Section 5.2.3 Air Leakage Exceptions (Cont’d)

**Doors **
**directly into dwellings**
**into spaces less than 3000 ft****2**
**at building entrances with revolving doors**
**for vehicles and material handling**

## Section 5.3 Prescriptive Building Envelope Option 

**Limitations:**
**Vertical fenestration ******** 50% of gross wall area **
**Skylight fenestration area ******** 5% of the gross roof area **
**Envelope components must comply with the criteria in Table 5-3**

## Designer Specifies
R-values for walls, floors, and roofs 
U-factors for opaque doors
U-factor and SHGC for fenestration, OR
Designer uses pre-calculated assemblies from Appendix A

**R-values for walls, floors, and roofs **
**U-factors for opaque doors**
**U-factor and SHGC for fenestration, OR**
**Designer uses pre-calculated assemblies from Appendix A**

** **

- Section 5.3 Prescriptive Building Envelope Option (Cont’d)

## Appendix A

**Includes pre-calculated U-factors, C-factors and F-factors for**
**Above-grade walls**
**Below-grade walls**
**Floors**
**Slab-on-grade floors**
**Opaque doors**
**Fenestration**

## Section 5.4 Building Envelope Trade-off Option

**The proposed building must comply with 5.1 and 5.2**
**The *****envelope performance factor***** (EPF) of the proposed building is **
**calculated in accordance with ****the procedures in Appendix C**
_***<***_*** *****the EPF for the budget building**

## Normative Appendix C

- Specifies the trade-off methodology to be followed
- ENVSTD
- A windows-based computer program for applying Appendix C
- Covers all building envelope components
- Drop down menus
- Output demonstrates compliance