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home energy rating provider
Energy Service Professionals

Maximize property values. Minimize costs.

Whether a New Hampshire home is in the planning or construction stages or already existing, GDS Residential Energy Efficiency team provides comprehensive home energy audits to identify how to maximize the home’s energy efficiency from a whole house perspective now and in the future.

Homeowners and builders receive a computer-generated report that details cost-effective home improvements that can dramatically increase the energy efficiency of the home. GDS audits and home energy ratings include evaluation of:


Framing/design (new construction)


Heating and cooling






Water heating


Geothermal, solar and other potential renewable energy options


Air-infiltration through doors, windows


Major appliances


All of GDS energy audits and home energy ratings use air-infiltration testing (via Blower Door) and duct leakage testing (via Duct Blaster® equipment).

Blower Door Test—Proper Air-Infiltration

This test locates the largest and most costly air leaks in a home and determines if there is an adequate supply of fresh air in the home without mechanical ventilation (and whether mechanical ventilation is required).

Duct Leakage—Rooms too hot or too cold?

Leaking duct systems are a major source of heat loss—up to 25%–in existing and new homes. Leakage can hinder heating and cooling systems from distributing air accurately, resulting in rooms that are too hot and others that are too cold. Leaks in return ducts can draw in pollutants and other irritants creating indoor air quality problems.

Infrared (IR) Thermal Imaging

Using infrared technology, inspectors can diagnose insulation and moisture problems using technology to investigate building components by a less invasive means.

Combustion Safety Testing

Combustion appliances (furnaces, boilers and water heaters) need to be properly vented and under a worst-case depressurization must still vent dangerous flue gases properly. We test for flue-gas spillage from boilers, furnaces and water heaters; and for gas such as carbon monoxide (CO).

Appliance Metering

Major appliances like refrigerators are primary energy users. As part of our audit, we can monitor the electric usage of these appliances


There are two primary home energy rating programs: ENERGY STAR and Home Energy Ratings (HERS). GDS is registered as an ENERGY STAR partner and accredited by HERS.


ENERGY STAR Rating process is:


Energy analysis based upon plans – An analysis of building plans and specs provides a preliminary energy rating and recommendations are made to improve the design and/or specs for the purposes of energy performance and to achieve the required energy rating of 70 or lower;



Mid Construction Inspection – An on-site inspection must be performed after the insulation is installed but prior to the sheetrock installation. Other mid-construction inspections may occur during the construction process;


Final Inspection – Upon the homes completion a final inspection is conducted using state-of-the-art blower door and Duct Blaster (if applicable).

Home Energy Ratings (HERS)

GDS is an accredited home energy rating provider and performs unbiased third-party energy ratings using a point system by which homes can be compared for their level of energy efficiency. HERS scores can be used to qualify homes for the following programs: 


Energy Efficient Mortgage (EEM) products of the Federal Housing Administration (FHA), Fannie Mae, Freddie Mac and Veteran’s Administration (VA).



Environmental Protection Agency’s (EPA) and utility-sponsored ENERGY STAR Homes program;


Federal energy tax credits under the Energy Policy Act of 2005 (EPACT 2005);

HERS scores can also be used to help verify compliance with building energy codes.


Problem Solving

Our team helps homeowners solve problems including comfort concerns, window condensation, ice dams, moisture in the attic and high gas or electric use.

LEED for Homes Third Party Verification

As an approved third party consultant, we ensure your new home meets requirements for LEED certification.

Solar Hot Water Site Assessments

Our certified site assessment documents the potential for a solar system at your home.

Forced Air Furnace Whole System Analysis

We measure and document your system specifications. This ensures proper airflow distribution and that manufacturer’s installation recommendations are met.

GDS is also a member of the following organizations:


Association of Energy Service Professionals (AESP)


Builders Association of Greater Boston (BAGB)


National Association of the Remodeling Industry (NARI)


GDS staff are members of the NH – Residential Energy Performance Association (REPA)


Northeast Home Energy Ratings System Alliance (NEHERS-Alliance)