Here are some examples below:
- What is my climate? Do I use air conditioning or heat more? Is it humid or dry where I live?
- What direction does my home face in regards to the sun exposure? Is it mostly shady or does my home receive direct sun most of the day?
- How much can I afford when it comes to insulation?
- Are there any pre-existing conditions which would determine the type of insulation I should use?
- How is the condition or presence of a vapor barrier on my home?
- Will the insulation be exposed to any of the elements? Air, rain, animals, etc.
- Do I want to decrease my energy bill as much as possible, or is my home already quite efficient?
- Where are my HVAC units located?
- Do I have a hot damp crawl space or a hot damp attic?
- Is this an older home or new construction?
Below I will share with you the choices that we made and why we made them:
The single most important number one place that needs to be insulated well is at your roof deck, and the best insulation out there is spray foam. We chose closed cell spray foam because it also adds some vapor protection and we are housing our HVAC units in the attic... this will put them underneath the insulation and within our thermal barrier, thus making them more efficient. We did pay about twice as much for it as we would have if we had gone with regular insulation, but a few thousand dollars now will save much more in the future.
Exterior Walls | R-19 batt insulation:
There are studies out there that have been conducted and there is also conflicting information about sealing a house too "tight" and that it "needs to breathe." This is one of the reasons that we went with batt insulation at the exterior walls. We want to keep out MOST of the water and humidity and heat down here in the south, but if some water happens to get in our walls via a window, etc. it will be able to get back out.
Crawl Space | R-30 batt insulation
This would have been the area in which I would have chosen to add spray foam if we could have afforded it. Even upgrading to R-30 in lieu of R-19 only cost about a quarter of the price of spraying foam underneath our house. We saved several thousand dollars and if we decide to add it in the future, it is much easier to add here than at the roof deck or within the envelope of the house.
Sound Batt Insulation
Any area that you can add sound insulation, especially between floors and including bathrooms, media rooms, and bedrooms at least, do it! I would say to just insulate at every interior wall for simplicity, but this may not be feasible. It cost us about $1,000 to have a much quieter house, but I have a feeling that after they install, we will be buying additional rolls from a hardware store and sticking it where we can!
I hope this helps! Any areas that I can share our home building experience with you, I will try to do it!
Note: Compressing batt insulation decreases the value of it... never force extra into a large space - leave it soft and lofty for maximum insulation-ability.