Berkeley, United States of America


A city mandate/ordinance requiring that all households meet certain building standards when they are sold, transferred or renovated. This city-wide ordinance with various specific measures has reduced residential energy consumption by over 13 percent, annually reduced CO2 emissions by over 5,000 tons and allowed households to save up to $450 US dollars on their energy bills.

What is it?

RECO, Residential Energy Conservation Ordinance, is a city law which mandates that all residences (homes, apartment buildings or mixed use buildings) sold, transferred from one proprietor to another, or renovated exceeding a total permit value of $50,000 must comply with certain energy and water efficiency requirements.

These requirements meet or exceed California’s Title 24 Energy Codes, which are also mandatory but are only in effect when properties are remodeled. RECO covers conditions of sale and transfer, and has an immediate effect on household energy consumption.

The intent of the ordinance is to assist residents in reducing their energy bills while achieving an overall reduction in energy consumption. There is evidence that this is working. The City of Berkeley has lower overall energy consumption per capita than other regions of California. California has the lowest energy consumption per capita in the United States.

How does it work?

  • Owner of a property with a value of $50,000 or more must take full responsibility of complying with RECO measures.
  • Owner has one year from date of purchase to install all required energy and water efficiency measures.
  • Homeowner contracts a non-profit organization, CESC, Community Energy Savings Corporation, for a final inspection once the measures have been met.
  • Spaces larger than 1,500 square feet classify under commercial spaces and therefore must meet CECO, Commercial Energy Conservation Ordinance, measures.
  • Maximum expenditure allowance is 0.75% of final sale price, or $750 for each $100,000 of sale price and fraction thereof.
  • Berkeley receives funding through the California Energy Commission’s Public Goods funds and contracts with a local non-profit organization, Rising Sun Energy Center, to offer low-cost attic insulation at $0.40/ft2, for a total approximate cost of $500 per household (retail value is $2,300). Since attic insulation is generally the most expensive measure, this helps achieve 100% compliance with the ordinance.

RECO requirements (as taken from RECO’s online compliance guide):

  • Toilets:
  • 1.6 gallon/flush or flow reduction devices; $25 to $100 rebate on low-flow toilets available free through EBMUD (East Bay Municipal Utility District).
  • Savings: $3.50/year on water bills.
  • Showerheads:
  • 3.0 gallon/minute flow rate; Available free from EBMUD.
  • Savings: $10.00-$52.00/year per unit installed.
  • Faucet aerators:
  • 2.75 gal/minute flow rate for kitchens and bathrooms; Available free from EBMUD.
  • Savings: $4.00/year per unit installed.
  • Water Heater Blankets:
  • Insulation wrap of R-12* value.
  • Savings: $12.00- $66.00/year.
  • Hot & Cold Water Piping:
  • Insulate the first two feet from the heater to R-3 value;
  • Savings: $10.00- $70.00/year.
  • Hot Water Piping in Pumped, Re-circulating Heating Systems:
  • Insulate all pipes to R-3 value.
  • Savings: $10.00 - $70.00/year.
  • Exterior Door Weather-stripping:
  • Permanently affix weather stripping, and door sweeps or door shoes.
  • Savings: $10.00 - $70.00/year per door.
  • Furnace Duct Work:
  • Seal duct joints add insulation wrap to R-3 value;
  • Savings $88.00+/year.
  • Fireplace Chimneys:
  • Must have dampers, doors or closures.
  • Savings: $165.00+/year.
  • Ceiling/Attic Insulation:
  • Insulate to R-30 value or greater.
  • Savings: $280.00+ /year.
  • Common Area Lighting in Multi-Unit Buildings:
  • Replace incandescent bulbs with compact fluorescent lamps (CFL) of at least 25 lumens; these cost $10-15 each but last up to 10,000 hours versus 750 hours for incandescent bulbs. A 20-watt CFL is equivalent to a 75-watt incandescent bulb in output.
  • Savings: Payback period is 6-10 months at current electricity rates. A CFL uses 1/4 the watts of an incandescent bulb, thus, CFLs will save up to 75% of energy costs.

*“R” stands for the amount of Resistance a particular material has to heat loss. Materials with air pockets, such as fiberglass batts, or loose fill insulation such as cellulose, are better at insulating than dense materials, such as stucco or tile.

Next steps 

Berkeley is in the planning stages of revising the ordinance to be performance-based as well as prescriptive-based. This would allow some flexibility in the measures, as long as the overall energy performance is reduced, preferably through passive means. A performance approach would allow residents to install and achieve credit for measures such as insulated glass windows, basement or crawlspace insulation, high R-values in attics, or even the use of non-conventional building materials, such as strawbale. This revision is being coordinated with two neighboring cities, Oakland and San Francisco, both of which have far larger populations, and it is accepted that many people relocate between these three cities.


  • Other cities might adopt this simple prescriptive approach for their residential housing stock. Care should be taken that the energy measures are adequate for their Climate Zone, based on heating and cooling degree days (HDD and CDD). For example, while Berkeley has a fairly mild, Mediterranean climate, a R-30 attic insulation is effective, whereas this may be inadequate for hotter or colder climates, such as Boston or New Orleans. Adjustments should be made to the measures that adequately address seasonal temperature variations, as well as diurnal and nocturnal variations.
  • Other measures not included in this current ordinance, such as the use of fluorescent lighting in place of incandescent could also be adopted.
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