Energy Efficient Homes and Florida Vernacular

Indiantown Non-Profit Housing, Inc.’s Impact on

Energy Conservation in Martin County.


Starting in late 2010, Indiantown Non-Profit Housing, Inc., (INPHI) in partnership with Martin County successfully reduced the number of abandoned homes in the County. The severe economic conditions and bad lending practices combined to produce a large number of homes that were abandoned and vacant.


INPHI with the support and monies from the US Department of Housing and Urban Development’s Neighborhood Stabilization Program (NSP),  through the Florida Department of Economic Opportunity and Martin County, to purchase abandoned homes. Abandoned homes in these neighborhoods were targets of vandalisms and neglect. The impact on the adjacent property values / tax base and neighborhood safety was on a decline. INPHI purchased and refurbished the homes for low and moderate income families. These homes had stood vacant for sometimes as long as three or more years.


Revitalizing abandoned homes in the local neighborhoods not only stabilizes the areas and makes them safer but saving the existing structures is by far a more energy efficient approach to construction than building new. All the energy it takes to tear down an existing home, fabricate new materials, ship them to the site and build can all be saved. This rehabilitation strategy provides a more energy efficient and lower cost home for the new owners with up-to-date features.


Indiantown Non-Profit Housing, Inc. contracted with Thomas T. Cooper, AIA, architect,who specializes in “Green Architecture” or Sustainable Design, to provide professional consulting services for the homes to be renovated. The primary purpose of the renovation was to make the homes as energy efficient, healthy and safe as possible within a very tight budget. The guidelines used for these renovations were the Florida Green Building Coalition (FGBC) Homes Standards.


The FGBC standards are similar to the nationally recognized LEED standards except that they were developed prior to LEED, are Florida specific and more streamlined to administer. These guidelines address:


  • Energy
  • Water
  • Lot Choice
  • Site
  • Materials
  • Health
  • Disaster Mitigation


There are twenty-one abandoned homes that INPHI purchased, renovated and either rented or resold to new home owners. Most of the buildings were single family, detached, one story concrete block homes. There were however, a few duplexes and frame construction homes in the mix. All of the homes had an analysis that included observations and a record of existing conditions, age of house and appliances / air-conditioner, a blower door test and duct tightness test.


After this analysis, a plan of action was established to improve the energy, water, health and safety (disaster mitigation) conditions of the house within the individual project budget.


The plan of action or Work Specs for most of the homes included the following energy related remedial items:



  • Air seal the house (weather strip, caulk and seal)
  • Attic insulation of R-38
  • Solar window screen or window tint film
  • Smart thermostats
  • Compact fluorescents throughout house
  • Seal and insulate air-conditioning ducts
  • Solar hot water system in almost all homes
  • Energy Star rated ceiling fans
  • Energy Star rated refrigerators, dishwashers, clothes washer / dryer
  • Energy efficient stoves and ovens
  • Energy Star rated bath and kitchen exhaust to exterior
  • SEER 14 air conditioners or better where needed in a few cases.
  • Paint inside and out with high reflectance paint


The Work Specs also included improvements to the following major areas of concern:


  1. Increase water efficiency (dual flush toilets, low flow shower heads and sink aerators),


  1. Increase indoor air quality (increase A / C filter efficiency, replace carpet with tile or wood flooring)


  1. Strengthen the houses against hurricanes (new hurricane impact windows and doors or shutters and gable end bracing in the attic) and


  1. Protection against mold and humidity (downspout extensions and exterior caulk, seal and paint).


It was the energy efficiency improvements which marked these homes as excellent buys for families who were looking to save something in excess of 20 % - 30 % of their power bill. This money could then be available to help with the monthly mortgage payments.


One other energy efficiency improvement that was applied to a few of the houses was landscaping in the Port Salerno Community Redevelopment Area (CRA). The CRA funded the basic landscaping improvements for three homes in their neighborhood. The sod installed was drought tolerant able to survive without irrigation. The trees were planted to aide in the shading of the south and west walls of the homes and also to provide street trees to encourage shaded walks for the pedestrians.


The improved homes could all be described as average in size and configuration, from 1,100 square feet to 1,400 square feet. The lessons learned from these twenty-one homes can easily be translated to 80 % or more of the homes in Martin County. Although each home is different due to size, orientation, year the home was built, layout of rooms and windows, materials, etc. they all will show a dramatic reduction in energy cost. One example residence shows the change in energy consumption after remodeling.


The building built in Stuart, Florida in 2004 is a single story, 1,131 square foot, concrete block and stucco duplex. In the years before it was purchased by Indiantown Non-Profit Housing, Inc. the energy use by the duplex, according to Florida Power & Light, Co was 13,960 kWh annually.


The remodeling which included increased insulation in the attic (R-38), new energy efficient windows with tinting, compact fluorescent light bulbs, solar hot water heater, all new Energy Star rated appliances, ceiling fans and light reflective paint both inside and out. The annual energy costs projected on the first two months power bills (April 801 kWh and May 747 kWh) will be 9,288 kWh for the entire year. This would mean an energy savings of 4,672 kWh or a

44 % reduction in the energy consumption of the house.


FP & L provides a reduced rate of .08570 cents per kWh where the consumption is under 1,000 kWh. Both of the months reported for the duplex are under this threshold, therefore the rate charged is .085270 cents per kWh. The electric consumption prior to remodeling exceeded the 1,000 kWh thresholds so the rate paid was .105270 cents per kWh for those parts of the month that exceed 1,000 kWh.


Previous cost @ 13,960 kWh (12,000 x .085270 = $1,023.24 + 1,960 x .105270) = $1,229.57

Current cost @ 9,288 kWh x .085270 = $ 791.99 after remodeling




With all other aspects remaining the same, the older residences will demonstrate the greater percentage of energy savings. Therefore, the most productive energy saving strategy would be to analyze and rehabilitate the homes and business buildings in Martin County starting with the oldest. The older buildings in Martin County were not built to the higher energy conservation standards of newer construction.