9.4   Mandatory Requirements

The mandatory measures apply to all added or altered envelope components as they do to new construction, regardless of whether the prescriptive or performance compliance method is used. This section describes the mandatory requirements for low-rise residential buildings as they apply to additions and alterations.  More information on the mandatory measures is in Chapters 3, 4, 5 and 6.

9.4.1    Envelope Measures

Envelope mandatory measures are 'listed below, including the relevant reference in the Standards and the section number in this 'manual.  The following measures include  products and exterior doors, insulation, roofing products and radiant barriers. See Sections 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, and 3.8 for more information.

a.   Manufactured fenestration products and exterior doors air leakage infiltration rates, see §110.6(a)1, Section 3.5.2;

b.   Fenestration U-factor, SHGC, VT ratings, see §10-111, §110.6(a)2, 3 & 4, Section 3.5;

Fenestration temporary and permanent labels, see §110.6(a)5, Section 3.5;

Fenestration maximum weighted average U-factor = 0.58, see §150.0(q),
Section 3.5;

Installation of field-fabricated fenestration and exterior doors, see §110.6(b), Section 3.5;

Sealing joints and other openings, see §110.7, Section 3.6;

Certification of insulating materials, see §110.8(a), Section 3.6;

Restrictions on use of urea formaldehyde foam insulation, see §110.8(b),
Section 3.6;

Flame spread insulation ratings, see §110.8(c), Section 3.6;

Insulation placement on roof/ceilings, see §110.8(e), Section 3.6;

Minimum roof/ceiling insulation, see §150.0(a), Section 3.6;

Minimum roof/ceiling insulation in an existing attic, see §110.8(d)1 and §150.0(a), Section 3.6;

Roofing products (cool roofs) solar reflectance and thermal emittance rating and labeling, see §10-113 and §110.8(i);

Loose-fill insulation, see §150.0(b), see Section 3.6;

Minimum wall insulation, see §150.0(c), see Section 3.6;

Minimum floor insulation, see §150.0(d), see Section 3.6;

Slab edge insulation moisture resistance and physical protection, see §150.0(l), Section 3.6;

Insulation requirement for heated slab floors, see §110.8(g), Section 3.6;

Vapor retarder §150.0(g), see Section 3.6.

9.4.2    Ceiling/Roof and Wall Insulation

When insulation is installed in the attics of existing buildings, at least R-30 shall be installed in all climate zones. When ceilings without attics are altered, at least R-19 shall be installed between wood-framing members; or enough insulation shall be installed to achieve the equivalent of R-19 insulation between wood framing members. When the space between framing members becomes accessible as a part of a ceiling/roof modification, the ceiling/roof is considered altered and the insulation measure applies.  However, if the roofing surface material is replaced but the roof sheathing is not being removed, there is no insulation requirement.

Existing buildings that already have R-11 insulation installed in framed walls are exempt from the mandatory minimum R-13 or R-19 wall insulation required by §150.0(c) if the building can demonstrate performance method compliance with the walls modeled as R-11.  

9.4.3    Roofing Products: (Cool Roof)

Roofing products installed either to meet prescriptive requirements or to take performance compliance credit for reflectance and emittance are referred to as “cool roof”.  These roofing products must be certified by the Cool Roof Rating Council (www.coolroofs.org) per §10-113 and §110.8(i). 

To be considered a cool roof the roofing products manufacturer must have its roofing product tested for solar reflectance and thermal emittance, and be 'listed in the Cool Roof Rating Councils (CRRC) Rated Product Directory. Figure 9-1 provides an example of an approved CRRC product label.

Figure 9-1 CRRC Product label and information

If the aged value for the reflectance is not available in the CRRC’s Rated Product Directory then the equation below can be used until the aged rated value for the reflectance is posted in the directory.

Equation 9-1 Aged Reflectance

Aged Reflectance_calculated = (0.2+β[ρ_initial – 0.2])

Where:
ρ_initial = Initial Reflectance 'listed in the CRRC Rated Product Directory.
β = soiling resistance value which is 'listed in Table 9-2

Table 9-2 –Soiling Resistance Value β, By Product Type

9.4.4    Fenestration

Fenestration which is new or replacement (altered) glazing – including skylights -- must meet the maximum U-factor requirement in one of three ways:

1.   Every fenestration product (glazed opening) meets the mandatory maximum U-factor of 0.58; or

2.   All new or replacement fenestration combined meet the mandatory maximum of 0.58 U-factor using an area weighted average calculation; or

3.   the area of new and replacement fenestration up to 10 ft² or 0.5% of the conditioned floor area (CFA), whichever is greater, is exempt from the U-factor requirement per Exception to §150.0(q).

Example:  an existing 2,500 ft2 house undergoes an alteration with all the existing windows being replaced.  The owner may install up to 12.5 ft2 of new glazing (i.e., up to 0.5% of 2,500 ft2) without meeting the maximum U-factor of 0.58.  If the overall alterations meet the Standards with the prescriptive or performance approach (see Sections 9.6).

Consistent with Exception 1 to §150.1(c)3A: For each dwelling unit, up to 3 square feet of new glazing area installed in doors and up to 3 square feet of new tubular skylight area with dual-pane diffusers shall not be required to meet or be included in the area-weighted average fenestration calculation to meet the mandatory requirement of §150.0(q).

9.4.5    Greenhouse Windows

Greenhouse or garden windows are special windows that project from the façade of the building and are typically five sided structure. An NFRC-rated U-factor for greenhouse windows is typically quite high and may not meet the mandatory requirements for the fenestration U-factor of 0.58.

The three ways to meet this mandatory measure for greenhouse windows are:

Must have a maximum U-factor of 0.58 or better; or

Use the area-weighted average for all new and replacement fenestration with a combined mandatory maximum of 0.58 U-factor as per §150.0(q)2; or

The Exception to §150.0(q)1 for up to 10 ft2 or 0.5% of CFA, whichever is greater; or

When using the performance approach, Exception 1 to s. 150.2(b) states that any dual-glazed greenhouse or garden window installed as part of an alteration complies automatically with the U-factor requirements of s. 150.1(c)3.  However, these windows are not exempt from the SHGC requirements of s. 150.1(c)3.

9.4.6    Mechanical (HVAC) and Water Heating Measures

Mechanical (HVAC) system and water heating mandatory measures are 'listed below for additions and alterations. They include measures applicable to space conditioning equipment, controls and systems; water heaters, controls and systems, pool and spa equipment, controls and systems; outdoor air ventilation; pipe insulation; air ducts and plenums; and fireplaces. See Sections reference below:

1.   Appliance efficiencies and verification, see §110.1, Section 4.1.4;

2.   Space conditioning equipment efficiencies, see §110.2(a), Sections 4.2.1 & 4.3.1;

3.   Heat pump controls, see §110.2(b), Sections 4.2.1;

4.   Setback thermostats (in most cases), see §110.2(c), Section 4.5.1;

5.   No continuously burning gas pilot lights, see §110.5, Sections 4.2.1 & 5.2;

6.   Heating and cooling load calculations, see §150.0(h), Sections 4.2.1 & 4.3.1;

7.   Pipe insulation and refrigerant line insulation, see §150.0(j), Section 5.2;

8.   Duct insulation and protection of insulation, see §150.0(m), Section 4.4.1;

9.   Dampers to prevent air leakage, see §150.0(m), Section 4.4.1;

10.  Flexible duct labeling, see §150.0(m), Section 4.4.1;

11.  Duct connections and closures, see §150.0(m), Section 4.4.1;

12.  Duct system sealing and leakage testing, see §150.0(m)11, Section 4.4.1;

13.  Zonally controlled central forced air systems, see §150.0(m)15, Section 4.4.1;

14.  Mechanical ventilation for indoor air quality, see §150.0(o), Section 4.6;

15.  Fireplaces, decorative gas appliances, gas logs, see §150.0(e), Section 4.2.1;

16.  Water Heating Systems, see §150.0(n), Chapter 5;

17.  Solar water heating, see §150.0(n)3, Section 5.5;

18.  Pool systems and equipment installation, see §150.0(p), Section 5.6.

9.4.7    Mechanical Ventilation

The whole building ventilation airflow requirement in ASHRAE 62.2 is required only in new buildings and in buildings with additions greater than 1,000 ft².  However, all other mechanical ventilation requirements in §150(o), including local exhaust, must be met, as applicable, in all additions and alterations.

When whole-building ventilation airflow is required for compliance, field verification and diagnostic testing of airflow performance is required in accordance with the procedures in Residential Appendix RA3.7. In that case, a Certificate of Compliance CF1R form must be registered online with a HERS provider (see Section 2.5 and Appendix A).

9.4.8    Lighting Measures

1.   Indoor and outdoor lighting mandatory measures are 'listed below. See Chapter 6 for more information.

2.   Lighting fixture (luminaire) requirements, see §150.0(k)1, Section 6.3;

3.   Switching devices and controls, see §150.0(k)2, Section 6.5;

4.   Lighting in kitchens, see §150.0(k)3, Section 6.6.1;

5.   Lighting internal to cabinets, see §150.0(k)4, Section 6.6.1;

6.   Lighting in bathrooms, see §150.0(k)5, Section 6.6.2;

7.   Lighting in garages, laundry and utility rooms, see §150.0(k)6, Section 6.6.3;

8.   Lighting in other rooms such as living rooms, dining rooms, bedrooms, family rooms and closets), see §150.0(k)7, Section 6.6.4;

9.   Recessed ceiling fixtures, see §150.0(k)8, Section 6.3.12;

10.  Outdoor lighting, see §150.0(k)9, Section 6.7;

11.  Internally illuminated address signs, see §150.0(k)10, Section 6.7.4;

12.  Garages for eight (8) or more vehicles, see §150.0(k)11, Section 6.7.7;

13.  Interior common areas of low-rise multi-family buildings, see §150.0(k)12, Section 6.8.

Altered lighting and any newly installed lighting equipment is required to comply with the residential lighting Standards, which apply to permanently installed lighting (Section 6.3.1) and associated lighting controls.

Only the lighting equipment that is altered needs to comply with the Standards. Existing lighting equipment is not required to be replaced to comply with the Standards. 

If a residential kitchen has eight existing luminaires, and only two of them are altered, then only the two altered luminaires need to comply with the Standards. This means, however, that low efficacy lighting cannot be added to an altered kitchen until at least 50% of the lighting in the finished kitchen becomes high efficacy. The newly installed lighting is also required to comply with the switching requirement.