What is a Home Energy Score? Essential 2021 Update

what is a home energy score

What is the Home Energy Score? 

“Home energy scores are a market-based solution for conveying previously unknown but critical information to both buyers and sellers of homes,” reads the City of Portland’s official guide. Home Energy Scores are similar to a miles-per-gallon rating for homes, allowing buyers to compare houses based on their energy efficiency. Homes are given a 1-10 score, where 1 is the least efficient and 10 is the most efficient. The Score is based on how much energy the home is expected to use assuming standard operating conditions and occupant behavior (not energy bills, which can vary between residents).

2. Are Home Energy Scores mandatory/why should I get a Home Energy Score?

For home sellers in Portland and Milwaukie, Home Energy Scores are required before listing your home for sale. There’s a $500 penalty in these municipalities for non-compliance. In addition, more evidence showing that buyers will pay more for a home with a Score under certain circumstances has come to light. Home Energy Scores make sense for anyone living in a house that isn’t brand-new and built to energy efficient standards. They show which improvements will go the furthest in reducing your energy bills, and are an important tool for buyers even in areas where they aren’t required.

3. Who provides the Home Energy Score, and how do I know they’re qualified?

To become a Home Energy Score Assessor, individuals must first qualify as a Home Inspector, or hold a similar credential, then be trained by the US Department of Energy to learn how to correctly score a home. Assessors must also obtain a CCB license — as a general or speciality contractor, or as a restricted Home Energy Performance Score Contractor in the City of Portland. Finally, they must be certified by Earth Advantage, and only Assessors on this list can legally provide the Score Report to comply with the ordinances Portland and Milwaukie. 

4. What is the process to get the score, and how much will it cost?

A Home Energy Score assessment can be scheduled online at your convenience. After spending 1-2 hours in your home (during which time you can be away from the home), the Assessor will provide a full report that includes details about how much it will cost to heat and cool the home, as well as the home’s carbon footprint and recommended actions to take. This report will be shared with your real estate agent if needed to comply with local ordinances to sell a home. The cost generally runs between $125-$200 (see our straightforward pricing guide here).

5. What improvements can I make to my home to boost my Home Energy Score?

Although every home is different, some patterns do exist in terms of the factors that cause low energy efficiency. This official list comes from the City of Portland’s 2020 evaluation of the HES program. Read the full report here. These are the improvements most often recommended by Home Energy Score Assessors in Portland, based on 20,000 homes scored:

  1. Professionally seal gaps and cracks that allow air leakage into the home 
  2. Professionally seal ducts to reduce airflow leakage 
  3. Upgrade water heater to a heat pump and/or choose one with an Energy Star label 
  4. Upgrade to a higher efficiency heating system and/or to a heat pump 
  5. Insulate exterior walls, attic, basement and crawlspaces

You can find guides and how-tos for all the items on this list in the DIY section of our blog.

6. Why are cities requiring Home Energy Scores?

Portland implemented its Home Energy Score program in 2018, but the idea has been around for at least a decade in the UK and European countries, and was more recently implemented in the cities of Austin and Berkeley. Milwaukie became the second Oregon city to require the HES in 2020, and several other cities are considering adopting similar policies. 

Home energy scores address two problems caused by inefficient homes: High energy bills for consumers, and high energy-based emissions that contribute to climate change. Studies have found that homes contribute nearly half of the greenhouse gas emissions attributable to buildings, and local studies have confirmed this to be true in the Portland area. Portland, Milwaukie and many other cities have set emissions-reductions goals, and these goals can’t be met without reducing energy use in homes. 

The beauty of the Home Energy Score policy is that it doesn’t require anyone to make changes to their home if they don’t want to. It simply makes information available to potential home buyers, while potentially compensating sellers who have made energy efficient improvements, either through government incentives or through the price premium that buyers are willing to pay for well performing homes.

5. Is there a difference between Home Energy Score, a Home Energy Audit and the Energy Performance Score?

Yes, and the Home Energy Score is the only way to comply with the ordinances in Portland and Milwaukie. The HES program was designed by the US Department of Energy as a real estate market-ready, standardized procedure that can apply to the widest range of homes. It has been integrated into the local RMLS so that Portland area home buyers can search for a home by its Home Energy Score. Lending products are also available through Fannie Mae and FHA that utilize the Home Energy Score.

A Home Energy Audit is much more involved than a Home Energy Score, typically taking 2-4x as long to complete. Some Portland Home Energy Score providers are offering this service as an above-and-beyond service to homeowners, at a premium cost. 

There is no standardized procedure for performing a home energy audit, but it will involve an in-person inspection of the home as well as specialized tests like thermographic imaging or a blower door test to find leaks in the building envelope. A home energy audit may be helpful if a homeowner has made improvements to the home based on a Home Energy Score report, but is still finding that the home performs less efficiently than they want it to. 

Finally, the Energy Performance Score was a product developed by Energy Trust of Oregon before Home Energy Scores became the industry standard. To avoid confusion, Energy Trust is retiring EPS. 

8. Are any homes or home sellers exempt from getting the Home Energy Score?


Only detached single-family homes are required to receive a Home Energy Score in Portland or Milwaukie. This means that stacked (vertical) condos, ADUs and houseboats are exempt from the policies. Exemptions are also made in circumstances where a home must be sold, such as a foreclosure.