HERS Rating for Energy Star Labeled Homes - for home builders

If you're building a house or residential building in Long Island or New York City, you will probably need a HERS (Home Energy Rating System) Compliance Certificate before you can break ground. We can help you here.

New energy codes have been instituted throughout Long Island since 2008 and are on the horizon for New York City. These codes require that new houses to pass a HERS rating and, with respect to construction techniques, go above and beyond what many builders have been used to doing for years. Rather than view this as a hardship imposed upon builders, it should be viewed as an opportunity to provide real value to home buyers and a front-line approach to reducing the energy demands of our country. Building departments have agreed that the only way to improve the energy efficiency of new construction is to make it part of the building code. The building departments, however, don't wish to have their building inspectors be involved in HERS ratings as specialized training and equipment is required. Therefore, the energy-efficiency aspects of construction are to be verified by third-party independent, certified HERS raters. We act as the eyes and ears of the building department and new construction will not receive a final Certificate of Occupancy without a successful HERS rating.

The HERS rating is a scoring system used to determine how energy efficient a house is. It is determined by a plans review, which is done before ground-breaking, to make sure that the proposed house, as designed, will pass a HERS rating. Various phase site inspections will follow to assure that energy efficient construction details are being executed properly. See "How It Works" below for further details.

The HERS rating used to be synonymous with the Energy Star Labeled Homes (version 2) program until Energy Star, version 3 (ESv3) came online in January, 2012. Since ESv3 is an extreme departure from version 2, requiring twice as many site inspections and more involvement from the HERS rater, building departments in this area have decoupled the HERS rating from Energy Star and now require new construction to simply pass a HERS rating, usually with an index of 70 or less.

Note that Energy Star version 3, although more comprehensive, is now voluntary, and will generally only be undertaken by builders who wish to distinguish themselves as high-quality home builders. We can provide oversight for Energy Star version 3 as well as basic HERS ratings.

The HERS rating process focuses on the following areas for energy-efficient construction:

How It works

We can work with home builders to help meet the energy codes and we try to make the process and smooth as possible. The HERS process generally runs like this:

Plans review and recommendations

Before ground can be broken, most municipalities will require a compliance certificate to be submitted by the HERS rater. During a plans review, we enter all of the building parameters into a software program only available to HERS raters called REM/Rate used specifically for HERS ratings. This preliminary review helps to establish whether the house, as planned, will pass or whether improvements must be incorporated into the plans. In most cases, designs do not need major modifications and can pass as drawn. The real challenge is in the execution of the construction. We can also recommend energy upgrades at this point and determine whether they would be cost-justified. We refer to the plans review file throughout the rating process until completion.

Thermal bypass inspection

Tub wall needs complete air barrier prior to tub installation

Prior to drywall and insulation, the building shell needs to conform to the Energy Star Thermal Bypass Checklist. This means that transitional areas traditionally left open in conventional construction must be sealed. We provide instructions as to how to follow the Thermal Bypass Checklist, which, for anyone familiar with construction, will not be a stretch. A little extra labor and minimal materials are all that is required. For example, the photo on the left shows the tub wall prior to tub installation. We see that there is a solid air barrier between the wall and tub.

Insulation inspection

Insulation needs to be in full contact with the surface it insulates

The insulation inspection is also done prior to drywall. Insulation must contact all 6 sides of the cavity it fills to be effective. Otherwise, up to half or more of the stated R-Value can be lost. An insulation inspection is done prior to drywall to verify no compressions or voids are present. This means that insulation must be cut to fit around pipes and wires and no more stapling to sides of studs. Other alternatives to fiberglass are encouraged, such as cellulose or spray foam. Cellulose is quite good at filling voids and spray foam, although more expensive, provides air sealing as well. Adding extra insulation under exterior siding can boost the performance of the house as well minimize or eliminate the thermal bridging that occurs with a typical stud wall.

Blower door testing for building shell air-tightness

Blower door tests shell leakage

A blower door is used during the final inspection to measure shell leakage, although some builders of high-performance houses opt to have a preliminary test done prior to insulation and drywall to identify leak points and make sure the project is on track. The shell leakage must not exceed 5 air changes per house at 50 pascals (5 ACH50) pressure, which is roughly equivalent to 0.35 natural air changes per hour or the house will not pass the HERS rating.

Duct blaster testing for duct air-tightness

Duct blaster measures duct tightness

Proper air duct sealing has historically been an afterthought by many HVAC installers, but this practice (or lack of practice) can result in significant sustained energy losses as well as pressure imbalances in the building. Duct sealing should be done with mastic (not foil tape) and testing must result in leakage-to-outside of no more than 6% of square footage of the house. This test is also pass / fail, so HVAC subs should be brought on board with the project to avoid project delays and extra costs.

Combustion Appliance Zone testing for all fuel-burning appliances

High-efficiency furnace

Combustion safety testing is required for all fuel burning appliances, including furnaces, boilers, water heaters and ovens. If carbon monoxide levels are too high or draft is too low, repairs must be made.

Worst case depressurization testing for potential backdrafting

A manometer is used to check pressure differences in the building

Exhaust fans, HVAC fans, and dryers can depressurize a tight house to the point where backdrafting could occur on fuel-fired heating equipment, resulting in dangerous combustion gases entering the house. We make sure that these conditions do not occur by creating a worst-case pressure scenario in the building. If pressure levels are inappropriate, repairs must be made before the house can pass muster.

Gas leak testing for gas pipes

Gas pipes are checked using a combustible gas detector

We verify gas-tightness of gas pipes. Leaks are sometimes discovered on new work.

The fees that are involved with this process will be more than offset by energy savings over the life of the home as well as incentives and rebates available through LIPA, New York State, and NYSERDA. Contact our office for pricing and other details.