According to Florida Energy Code there are several ways to calculate your project to see if it passes energy code. The 2 most used in the industry is: Form 402-2017 Prescriptive Code and Form 405-2017 Performance Code. The first form 402 tells the builder exactly what they are to use for constructs, with unnecessary burdens of high insulation values, lower windows specs, etc. However, Form 405 Performance Method, is a “trade-off” method which gives the builder/homeowner more flexibility and choices in what they want to install/use to build their project. Here at energycalcs.net we think our clients should have the choice of what constructs they want to use and where they want to spend their money on their projects, thus we use Form 405-2017. Through experience and training, we also advise our clients of “the best bang for their buck”, so to speak or share our knowledge of new and innovative products that they may not be aware of. As stated above Form 402-2017 states what you must use on every aspect of your building. For instance: Form 402 says you must have R38 in your attic (and although that is a wise choice), Form 405 states you only have to have R19 (again not that we advocate that, but it is ultimately the builder’s choice here). Form 402 states you have to have a minimum of R6 on concrete block walls, Form 405 states you do not have to have any insulation on the walls. (again something we would never recommend!) but it is still a choice to be made by builder. The reasoning behind this “performance” method is a “trade-off” theory, that allows you to have worse case constructs on one area of the build, while using above average constructs on others. It may be a higher SEER (efficiency) of your air conditioner, or very low E double pane vinyl windows and high efficiency water heater with lower value of insulation in attic and walls. YOU DECIDE!
SMALL ADDITIONS and ROOM ENCLOSURES
DON’T BE FOOLED! Any time an area goes from “unconditional space” or “un-air conditioned space” to “living space” or “air conditioned space”, a building permit must be obtained before air conditioning can be installed OR supplied to that area. (even a current enclosed room that does not have ac, or plans for enclosing a garage, sunroom, patio or lanai). The first step of applying for a permit, however, is the hurdle of passing Florida’s current energy code. Most of the time when asking the building dept about what form is needed for a “small addition” or “enclosing a room”, they will inevitably send the applicant to online source for Form 402-2017, also referred to as the “Prescriptive Code”. They will say, oh just “fill it out” with your plans and submit to building dept. I agree, it is as simple as you can get: just a page of check marks and simple information (please see sample form here). HOWEVER, WHAT THEY DON’T TELL YOU IS THE REQUIREMENTS ASSOCIATED WITH THIS FORM. (please view all 3 pages, not just the first page). Thus, once building has begun and inspectors start coming to your home, if the building constructs used do not meet the Prescriptive code (quite restrictive), you may have to add additional insulation, tear out windows that don’t meet the standards or ductwork that does not meet the required R Values. (READ THE FINE PRINT BEFORE YOU FIND OUT DURING INSPECTIONS THAT YOU DIDN’T INSTALL THE CORRECT CONSTRUCTION COMPONENTS AND HAVE TO ADD TO OR TEAR OUT WHAT HAS ALREADY BEEN INSTALLED). BE AWARE OF THE MINIMUM REQUIREMENTS BEFORE YOU BUILD!