I don't know about what to do in this case, but I do remember as a teenager; not knowing or caring about skin damage from the sun, that we used aluminum foil to draw the sun to us by making these odd contraptions and putting them under our chins. I'm sure you've checked this out but my first instinct would be, why are you doing this if you want to keep the house from being over heated? Again, I am a novice and am just giving my reaction. I am looking forward to what other experienced people say. I'm in Pennsylvania, 25 miles outside of Phila - North West of Phila. Today is in the high 90's and I'm afraid we're not going to get another family this year. Still hoping.

As I said before, its not about finishes in the basement; its about living underneath the rest of the family. Using the first floor spaces for daytime gathering, the second floor for private sleeping and the lowest level for utility is a centuries old tradition and it still works well. I don't agree that a basement is cheap space that can be cheaply finished. A walk-out basement usually provides windows on only one side unless you build expensive areaways for additional windows. The concrete floor will require serious insulation and sleepers for a wood floor as comfortable as the upper floor bedrooms. The basement floor will probably need to be a foot lower to allow an 8 ft ceiling height with utilities above it requiring additional excavation, concrete and taller forms. The ceiling will need additional sound treatment if he intends to study in his room. If your son is in the basement he will also have his own private entrance with less security. I realize most people don't worry about such things but the world now comes unfiltered into our children's lives on their phones and computers and its smart to think more defensively. I have 2 boys and a girl 32, 30 and 23 respectively. As children they each experienced the world differently as it rapidly changed. My wife and I saw an ad for fast broadband service where a mother said "we love the speed because we have so little time to spend as a family." We both started laughing. If you want to spend more time as a family it would be wise to start with turning the TV and computers off and designing your house so it doesn't feel like a fraternity or a tavern like the ones so often posted on this forum. I realize you haven't designed your house yet but when looking for the best arrangement for family spaces do it with family interaction in mind first and all the other considerations second. Apartments are for efficient living; houses are for raising families.

I'm piggy backing on the OP's original post because I am in a similar situation. I have an empty vented attic (no HVAC equipment or duct work) with blown cellulose on its floor between & covering joists (@ least to code if not exceeding) This attic sits over our master bedroom, master bath & master closet. Air in those room always seems to be 2-5 degrees colder or hotter depending on season. Have had HVAC equipment & airflow checked - all in line along with original blower door test which had us 50% tighter than the comps. So I think somehow air is still leaking down over this part of my house. The only reason is that the attic roof area is open to the air infiltration via a passive ventilation combination of eaves, ridges, & side gables & leaking air below to the master space. Foam would be at least 3x the costs of additional cellulose but beneficially make the attic temp closer to whatever below however, may require additional mechanical ventilation. Additional topping of blown cellulose would be no problem in an unused space but would it compact in the future & possibly get ineffective in a vented environment & have to be redone? What is the most effective but cost conscious way to insulate the attic if HVAC equipment is not up there to get my temps back in line with the other spaces in my house?

Decision has been made. My roofing contractor and I are an the same wavelength. I will have more eyebrow vents than you would believe. They will be as close as possible to the ridge like a few inches. The system will be completely passive. Nothing will wear out. It won't be necessary to crawl into an attic of extremely difficult geometry to install or perhaps service a fan. There will be no fan to vibrate or be heard. The venting at present is so minimal that hot air comes OUT the soffet vents. We don't need a 100% solution just a darn good one. There will be a VAST improvement. All my troubles will be over for ever and the world will be good again. ===================================== I inspected 2 ridge vents and 5 roofing contractors. I found: The ELK vent has only a 3/4 inch flow passage characteristic dimension. I don't believe that is large enough to establish significant flow for aerodynamic reasons. There are an unbelievable number of zig zag baffles to inhibit the air flow. The allowed opening in the ridge for this contrivance is only 2 inches. Not much is it? Thats a 2 inch inlet to a 3/4 inch high vent passage. Squirrels and birds put stuff in the vent openings especially bluejays. Bugs crawl into em. I looked at another brand which also had the same type drawbacks. Its baffles were foil shaped. Well La T Da. They blocked off 70% of the flow area. Its hot here. The ridge vents get soft and difficult to install; like nailing down spahgetti. They are made from polypropylene which in my experience just does not stand the heat and certainly not the sun. Insufficient ridge venting cannot be remedied with more vents as a short circuit will result. Insufficient Eyebrow venting can be remedied with more vents at the same roof level. Ridge vents might work. Eyebrow vents will work. =================================================================== MISLEADING ROOF VENT AREAS I measured 4 different eyebrow vents, 1 gable shaped vent and eyeballed a bunch on various roofs. I found: One eyebrow had a screened opening of 3 3/4 X 20 for an area of 75 sq in. But it had a vertical rain guard flap in front and the shortest distance from the edge of that to the lower surface of the xost pasage was 2.25 inch giving a true xost area of 2.25 X 20 = 45 sq in. The gable shaped vent had 6 louvers at 45º sort of Z shaped each with a rain lip and the top opening was semi-dome shape. The individual screens were about 1.25 inch high but the shortest distance from the rain lip to the lower surface of each louvre was 5/8 inch. The face opening was 8 x 20 overall implying 160 sq in vent. But the actual effective openings including the upper dome totaled 84 sq in. Great diligence must be exersized in any attempt to match upper roof vent xost areas to soffet inlet vent areas. The nominal dimensions of the various vents may imply xost flow areas at a wide variance from and greater than the actual flow areas. ==========================================