Building a BETTER attic - Unvented + Conditioned attics 101

We so need some videos on taking an attic like you had at the beginning and having it converted to a conditioned attic.

This is a valuable addition to my woodwork collection youtube.com/post/UgkxbnOKZBE4evMO5V2vroHeCjq6d_MV6… I still will rate this woodwork plan as the best in my reference library. It always seem to stand out from the rest whenever you go through the library. This is a masterpiece.

Im a HVAC TECH in south Texas and those conditioned attic spaces are lovely

I really like what I saw in this video. Very neat technology. I also like that you thought about the fresh air needs. I would not have thought of that need, but should have since I grew up in the days of the gas space heaters. As a former volunteer fire fighter, no or at least less smoke is a big deal. Current trends are to cut a bunch of holes in the roof to let the smoke and heat out so you can see where the fire is. In a house fire with someone trapped, the firefighters had to back out when the FLIR camera showed the temperature at 742 degrees, roughly 4 feet off of the floor. The trapped person didn't make it. As the fire captain said, "no one survives that kind of heat". The open core bedroom doors just went whoosh and only the frame was left. This was a 50 year old brick 3-sides house with typical shingle roofing. That was the problem. With the room temperature that high, the tar on the bottom of the shingles melted and dripped through the sheeting, then burst into flame in the attic - making the temperature that much higher. Once they got the attic temperature down a little, they were able to go in and pull ceiling to finish the lowering of the temperature. The whole thing was out in about 5 minutes after that. As a result of the SMOKE, the city inspector required that the left overs be taken to a special hazardous materials dump. The smoke alone caused everything to be classified as hazardous. If your house catches on fire, please remember what we taught you in elementary school, get flat on your belly and pretend you are an alligator then crawl out. Don't stand up! Your lungs can't handle the heat or the smoke.

Consider maybe a vid on how to convert a vented attic into an unvented conditioned attic?? If that even makes sense 😆

Having lived in a Texas home with a conditioned attic I can confirm it is an order of magnitude better than conventional. It was proven as my neighbors had conventional with Identical builder. I opted to spring for the initial $$ up front. Result? My heating/cooling costs were 1/3 my neighbors with same size homes (2500 sq. ft). No Dust, no bugs, super quiet, and no dread when handling things in attic. I can verify also the cost upfront was easily offset by energy savings, and no doubt made my home sell at a higher price than comparables due to my ability to prove energy costs based upon actual bills. I will never live without a conditioned attic ever again.

My attic used to go to 130F in summer. I had spay foam installed and it rarely reaches 90F. The electric bill has been reduced by about one third. But the more important thing is that the AC cools the house much easier. From Atlanta… the other benefit is that the attic is much more usable because you don’t temperature extremes. My attic is floored so it’s like adding extra rooms to the house.

A few years ago I re-did my attic in probably the largest home improvement project I will ever do lol 1950s house, and the attic was finished in the 1970s, and the thin drywall and cheap wood panneling was falling apart, and it was always hot/cold up stairs. Gutted everything except the framing, then added a spacer on the roof line, then a radiant barrier, then batt insulation, and then thick drywall. It changed so much! Still need AC units in the summer, but much smaller units keep up well even on medium where we used to have much larger units on high all summer. Things are quieter, cleaner, less humid, and everything is working really well. Next step is figuring out something for the AC/heat up there. Heat rises, and that is the only place to escape to, so it stays comfortable in winter, but there is a lack of air flow/exchange, and during the summer AC is absolutely required. The rooms all have HVAC supply vents... but no returns. Our HVAC is from the late 80s, and it is kind of a miricle that we havent had any issues with it yet, so we are saving up to replace it as the next big home project... that that will be a doosey, but I wont do that one myself. Hoping to move the HVAC to a different location in the basement (what use to be a garage that is walled off), and re-route all of the supply and return vents in the whole house to make more sense and work better. Should be the last step of 'functional' changes to the home before we go nuts with purely aesthetic changes to finally make our old 1950s wrecker look as nice as it feels to live in since I have done so much work on the electrical, insulation, and water management aspects of it. We have the biggest home on the street, and the lowest power bill, but we keep the house at 70* year round while most neighbors keep things at 75 in summer, and 60-65 in winter. Been a lot of work, and it is nice to feel results. Cant wait to make it look nice and 'see' the results.

Up in the nothern states at least near me its called a hot attic because it's heated in the winter

Here’s the issue with unvented attics. The home will self destruct in the absence of electricity (unvented attics REQUIRE air conditioning underneath constantly). Many homes in Florida that either went without power due to hurricane or foreclosure filled up with black mold. Most had to be stripped to the framing to repair. A vented attic is self-drying without power so for our off-grid ready home an unvented attic would have been a horrible choice. I like your videos but when you omit all the cons while touting the pros it seems like a sales pitch.

Amen to the importance of a sealed attic, Matt. When I insulated mine, nobody wanted to believe me that it was going to be 75 degrees in side with 100 outside. Got the proof today! 101 outside, 71 inside. During the manual J calculations I had to argue with the engineer that I wasn't going to have 40% energy loss in the attic because all my ducts were in the conditioned space. And because the attic is my return air "duct" that saves even more energy. My A/C guy and I decided to downgrade from a 5 ton unit to a 3 ton after he saw the results. Thanks for the great videos. Amazing what one can learn!

I used radiant foil OSB when I built my house in SoCal, the attic was 20° cooler than the outside in 100°+ days. Well worth the additional cost.

Remodeled a 3 apartment house using only rock wool as insulation for both temperature and sound. Worked wonders, afterwards you could not hear a sound between the apartments while before you could understand any conversation that was above a whisper. Not only is rock wool wonderful to work with, it's not itchy in the least. And as a bonus, it also acts as a fire barrier.

These building methods are going to be really nice for high ceilings in open living spaces, giving the R value it needs while making the interior a georgous space to look at... I really like the idea of having a conditioned attic for storage too!

Looks great. Here in South Texas we look at all things depending on budget. So we use radiant barrier sheathing with a combo of poly to keep attic cooler while staying in a decent budget.

In England, a 'conditioned roof' is referred to as a 'warm roof'. In colder climates (colder than Texas is most of the time - but maybe not MUCH colder) it's vital to have a vapour control layer (VCL - usually a membrane) on the warm (inside) side of the insulation so that moisture-laden warm air cannot move from the living space towards the colder outside, which would result in interstitial condensation. This is ruinously damaging for out of sight woodwork. What we learnt as householders doing a retrofit conditioned roof was that most roofers knew less about this new constructional method than we (who had taken an interest) did. They, being used to loft spaces being ventilated, just did not 'get' the importance of the VCL....which is very tricky to implement properly at abutments and penetrations. A warm roof, as Matt says, is brilliant - but it has to be done right.

having been raised in Florida all my life I would have to say this is the best idea I ever saw on building an attic the right way

By rerouting some of the vents and piping you could make extra bedrooms or a large hobby room in the attic. This has become quite popular in Scandinavia with attics and basements, often making enough space for a studio apartment.

Great video. It's always important to talk about designing safety into a build. Would love to hear more about some of the costs associated with the types of insulating and conditioning strategies you prefer, from foam to intumescence to that zender.

I cant thank you enough for these videos Matt!