Green Architectural Design – Seven Elements to Incorporate into a House

What can we do as a society to improve our physical environment and make our homes greener?

Newcomers to the City of Miami don’t know what it was like to live here or in the Caribbean in the 1950s or 1960s. My family used to vacation here in the 1960s. We came from Cuba in 1961 and moved north, but We come here once or twice a year on vacation.

In the 50’s or early 60’s no one had central air conditioning. Most people would have window or wall air conditioning units in their homes. And many houses did not have air conditioning at all.

So how were the houses designed then? Well, most houses were designed for good cross ventilation. They had windows with shutters or awnings. Either of these allowed the entire window to open to let in the breeze, unlike single-hung or horizontal sliding windows that only open halfway. The ceilings were high and often had ceiling fans. Although most of the houses had no insulation, between the high ceiling and the cross ventilation the summer heat was bearable. In places like Cuba where there were always crosswinds from the ocean, the summers were even more pleasant.

I remember when I lived in the sorority house at Georgia Tech in Atlanta while attending architecture school, there was no air conditioning in the house. We got by with a whole house exhaust fan on the second floor and honestly most of the time this took most of the heat out of the house making the sorority house pretty deliverable, even during the muggy Atlanta summer days.

Another detail that good architects took into account was the orientation of the house and the protection of the walls and windows. In our southeastern region of the US, the sun is almost never in the north, except for a few days in winter. The sun rises in the east and sets in the west and goes slightly south as it crosses the sky from east to west from sunrise to sunset. This means that the east, west and south exposures of a house need overhangs. Windows facing west need to be avoided, as the western sun is the hottest of the day. Also, the sun casts deep shadows. Being next to these windows is very uncomfortable in the afternoon. Windows facing east are very welcome as the morning sun is very pleasant.

How are most houses designed now? They ignore all this.

Air conditioning is the largest consumer of electricity in any home. The next most important user is the water heater. If we’re going to make a real tooth into what the typical homeowner uses in electricity, then a few things have to change in home design. In essence, we have to go back to the future.

Return to the future

There are a few simple things we need to change to improve the energy consumption of a typical Miami residence:

• Plan the house as if the air conditioning is not going to run all the time, 24/7. This means making sure the house is oriented correctly with good cross ventilation. Consider designing a house around a courtyard. High ceiling plan and large windows. Plan for ceiling fans in every living space in the house. So don’t run the air conditioner 24/7. Open the windows and enjoy the natural winter atmosphere of Miami.
• Strongly insulate attic space (R-30 minimum). Heat enters a house primarily through the roof. Only about 3% make it through walls. For Miami, this means that modest insulation in the walls is good enough (R-6 under the Florida Building Code of 2007 (FBC)).
• If possible, place the air conditioning ducts in an air conditioned space. This will maximize the efficiency of the air conditioner. The 2007 FBC, which is the code adopted by the City of Miami and applies statewide, requires R-6 duct insulation in non-air-conditioned spaces.
• If the home will have a tank water heater, make sure the water heater is installed on a timer so it doesn’t run all day. Miami is rarely cold, so the water heater can produce excellent hot water in 15 minutes. There is no need to run the water heater all day.
• Make sure the house has overhangs where needed. In the Miami area, that means on the southern, eastern, and western exposures. Sometimes shading devices such as blinds and screens can also be added.
• Consider putting several trees near the house to provide shade. This is a very effective way to decrease the roof’s exposure to the sun. This alone will lower the temperature around and in the house by several degrees. And, if at the same time, we can use gardens native to the Miami area that are drought resistant, then water use can also be reduced.
• Lastly, consider placing covered terraces, trellises, pergolas and/or porches around the house for use in the South Florida winter. So while everyone else is freezing up north, you can tell yourself how brilliant you are for choosing Miami as your home!