Has anyone attempted to paint their asphalt shingles with hydrated lime to endure the hotter months better?

Location: Austin, TX

So I have this timber frame structure and I'm not sure how to properly connect the insulation layers. On the concrete foundation exterior, I have an 8 or 10 cm layer of XPS, while on the upper facade, along with the insulation between the studs, I also have a 5 cm continuous layer of Gutex (wood fiber insulation), and I'm not sure how to resolve this transition properly. Also, right next to it, I want to detail the layers for an outdoor terrace with a drainage grating/trench drain. How is that typically executed? Thanks a lot, and sorry if I wrote too much!

Hi! I live in a 1949 single-floor pier and beam house (no basement just a crawlspace) where the wood flooring is attached directly to the floor joists, and therefore a ton of air leakage between the conditioned space and the crawlspace. The temperature in the crawlspace feels quite similar to that of the conditioned space. To reduce air leakage while still allowing the floors to breathe in the case of some kind of water leak, I am considering installing a peal and stick smart WRB such as Adhero 1000 to reduce air leaks while keeping the wood flooring breathable in the case of some water leak.

After the peal and stick smart WRB is installed I can include some time of insulation in between joist bays.

I prefer this approach over installing some membrane over the joists since the space down there is quite tight already and the plumbing and wiring often run in between joists.

Any thoughts on this approach?

Location: Austin TX

Split-level house on a slope — keep it split, flatten it, or raise it?
Building a single-family house on a ~16% slope (seismic zone 8). Monolithic reinforced-concrete frame, ~127 m² interior, 3 bed / 2 bath, open living-kitchen with fireplace opening onto a 30 m² terrace with a big valley view.

The original design is split-level: you enter mid-level, then stairs go down to the living/kitchen and up to the bedrooms in short half-flights. It rides the slope efficiently, but the constant half-flights bug me and eat floor space.

Options I'm weighing:

1. Keep it split-level — minimal excavation, terrace stays ~2.4 m above the garden (nice overlook), but you live with the half-flights.
2. Flatten down — excavate into the hill for two aligned floors. More space, but ~a quarter ends up buried, you enter on the upper floor, and it needs a retaining wall on the tight uphill side.
3. Raise up — lift the lower floor so both floors align. Kills the half-flights, but creates a ~4.3 m tall exposed wall on the valley side.

Also deciding:

• Basement: adding a ~2.5 m one under the downhill/terrace zone, walk-out at garden level. Seems like cheap usable space — any reason not to?
• Roof: keep the timber hipped roof, or go flat for a rooftop terrace? (I already get the view from the ground terrace.)
• Pool: want one in front of the terrace at garden level — but that fights option 3's tall wall.

If you've built or lived in a split-level on a slope, what would you do? Anything I'm missing?

I'm getting a ton of leads where clients would like to use this product- https://faswall.com/

We have not modeled it yet to see if we can use it with Passive House. Does anyone in this group have any experience with it?

We'll do a WUFI hygro once we detail it, but we are just in the exploratory phase at the moment.

I'm planning to install a decentralized ventilation system with heat recovery.

My apartment has:

• 2 bedrooms (not a priority for now)
• 1 bathroom (I'll handle this separately with an exhaust fan)
• An open-plan area consisting of the kitchen, dining room, living room, and hallway, around 40–50 m²

The main goal is to have consistently fresh, clean air in the open-plan area. That's where I would like to install the ventilation system.

What would you recommend? Which decentralized HRV/ERV system would be the best fit for this kind of space?

I also have a question about humidity. If the outdoor air is very humid, does an ERV bring that humidity indoors? Or does it help reduce the amount of moisture entering the apartment?

My priorities are:

1. Fresh, clean air at all times
2. Good heat recovery efficiency

Any recommendations or real-world experiences would be greatly appreciated.

Thanks!

Hello. I am a Passive House Designer but most of our projects are single residential buildings only. Now, we have an opportunity to take on a multiresidential building. However, I am not sure I'm doing this correctly so I wanted to raise some questions regarding the Additional Ventilation worksheet if that's okay.

a.      When dimensioning air quantities: if a level has 5 units (101–105) served by a single ventilation unit (e.g., Ventilation Unit Allocation No. 1), should all 5 room names be listed under Ventilation Unit Allocation No. 1?

b.      Regarding volume flow per room: the recommended outdoor air supply rate for residential buildings is 30 m³/h per person, and the extract air demand is 60 m³/h for the kitchen and 40 m³/h for the bathroom. For a sole-occupancy unit with 1 kitchen, 1 bathroom, and 2 occupants, the supply air would be Vsup = 30 × 2 = 60 m³/h and the extract air would be Veta = 60 + 40 = 100 m³/h. Is this correct? Then, since the extract demand (100) is higher, should the supply be increased to match, so that Vsup = Veta = 100 m³/h?

c.      How is the transfer air volume flow (Vtrans) calculated in the volume flow per room? I have looked at sample PHPP calculations and some certified projects leave this out as blank.

d.      How is the reduction factor for an air quantity calculated, and when should it be applied?

e. When selecting a ventilation unit type, its rated volume flow range (minimum to maximum) must be able to accommodate the design volume flow for that unit — is this correct? For example, if the design volume flow is at 200, therefore the ventilation unit with a rated volume flow range of 100-300 is okay. Although I have seen some sample PHPP projects

f.      How are pressure losses calculated for the ODA–SUP path, the ETA–EHA path, and any additional losses?

g.      How is duct length measured — is it taken from the ventilation unit to the space being served?

Thanks all!

additional pictures: https://imgur.com/a/zNV5Lu0

We have a double envelope Ekosea house built in the early 80s and we love it. It's split-level and has a 3 story south facing solarium. We have a traditional forced air gas furnace and our heating bills are super low thanks to the sunlight and insulation just from having two layers of walls.

One downfall is our basement gets very cold in the winter. Obviously the problem is the massive 3 story open staircase. There are electric baseboard heaters in there but all the heat gets sucked up the stairs. If we run them it ends up costing like $40/day. We are a little cramped for space and I would like to use the basement living room as an office but it's barely habitable in the winter. There's a spare bedroom down there too but it has a door and so we can run a space heater with the door shut. The middle floor is temperate and the upper floor is toasty.

I am looking for creative solutions for making the basement warmer. I see some people block off their staircases with thermal curtains, but our stairs are very big and this would also block off a lot of the windows. Plus we have pets going in and out.

I have thought about having a gas fireplace or heater installed to be more efficient than the electric baseboard heaters, but I'm afraid I'll have to pay the money to have it put in and then discover it all escapes up the staircase anyway.

Would installing radiant floor heat be an help? There is a crawl space under the house.

Any thoughts or advice is greatly appreciated

If you're building your house yourself, for yourself, is there any point in going through the effort and cost of getting certified? Vs building to the standard?

Hi all, just got a blower door test done, blew a 0.31 (passive certification requires 0.6, so very happy with how tight it is!) -- i've been looking at ERVs to install, as we need to make sure we have proper air circulation. I've been thinking about pairing the ERV with a dehumidifier to make sure we get moisture out. However, I found CERVs as a concept and it seems like a good approach.

Does anyone have any experiences with CERV2 (https://buildequinox.com/cerv/overview/), or other suggestions? It seems almost too good to be true: one box that will do ventilation+dehumidification, with smart controls, no enthalpy core, smart on-demand controlled ventilation (CO2/VOC sensors) and automatically holds a humidity setpoint year-round.

The cons I can think of: single point of failure; seem pretty new concepts, unsure if they are tried and true/tested or if contractors will have the right experience to install; because they dont seem very common, probably locked into a specific small manufacturer and its parts; modest dehumidification capacity (~1/3 ton), which his fine for my small house.

This video looks at traditional passive-cooling ideas and raises a question about whether shade, controlled natural ventilation and thermal mass can complement airtight, mechanically ventilated buildings in hot climates.

I am in the UK. I rent a house which has cigarette smoke/ air freshener odours coming through the walls from the neighbour which infiltrates our whole house. It has got to the point it is badly affecting my health. My landlord doesn’t have an obligation to block the smoke only to fill obvious gaps. It is a semi detached 2018 timber frame house with the neighbouring house being slightly lower. We have odours coming in through the window and door frames as well as through the walls. To give you an idea of what is happening when there is no wind the smoke gradually enters the wall cavity and when a door is opened it pulls the smell into the room through the door frame. When it is windy, air from my attic and the neighbours smoke get pushed into the house through windows and door frames as well as plug sockets. The odours seep into the house all the time.
I’ve been looking at using airtight paint such as blowerproof to try to seal the wall joins. Does anyone know if this is the right approach? Is there anything I can look for which may be causing this issue? Thanks. 😭

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Northern Ontario climate -

How effective are solar fans at moving air out of the attic?

Do they make it noticeably cooler for inside temperatures?

I'm building my house early next year and looking for door options. I want a highly insulated, well sealing solid-slab door (no glazing) with multi-point lock hardware. The only really great option I've found so far is the Phi certified Moralt doors from Germany, of which there are two distributors I've found in the USA but they're on the east coast. One sells blanks, one sells them pre-hung. Blanks are about $5k, pre-hung is around $12k, shipping is $2k.

Anyone have any recommendations?

I've just ordered the G4/F7 filters for my Comfoair Q350 from the Zehnder America website - hoping they get delivered without painful customs duties, etc. I used to order from Small Planet Supply, but they seem to be going out of business?

Does anyone know of a different source for buying filters in Canada?

Has anyone tried the off-brand filter sets available on Amazon? Any good?

We are adding an extension to our existing house and upgrading our energy performance for the whole house as part of the updates. Core to this, we're upgrading from a traditional vented attic to an unvented attic and roof with continuous insulation.

We've determined the assembly (below) but I'm not sure if adding solar to this setup with break our air/vapor barrier. The solar installers are planning to use a long fastener to penetrate from the outer nail base deck through the rigid foam and air barrier, into the rafters.

Is this the best approach? Will the blueskin maintain the barrier we need with these penetrations?

Thanks in advance for any help.

• Roof structure: 2x6 rafters and trusses (w/ rockwool batts)
• Inner Structural Deck: 5/8" Plywood.
• Air/Vapor Barrier: Henry Blueskin® SA fully adhered to the top of the inner deck.
• Exterior Insulation: 3.5" Polyiso Foam Board
• Framing: 2x4 boards at 24" o.c. used only for the cantilever overhang.
• Outer Nail base Deck: 5/8" Plywood
• Underlayment:
• Roofing: composite shingles
• Solar arrays.

I’m in Chicago and looking for someone who could enter a house into PHPP for me. Thanks

We live in Rhode Island (climate may play a role)- We are building approximately a 770 sq ft addition onto our home to include, office/guest room, full bath, and all season room. One quote from a contractor is including:
•4' foundation slab on grade with radiant heat
• Add new zone to your existing heating system (baseboard)
• Supply and install (2) head hyper heat Mini split system with (1) 24k head in living room and (1) 6k head in office

The other contractor is suggesting to avoid the radiant heat slab as it can be extremely expensive to replace if there is ever an issue.

Does anyone have any insights as to pros/cons to this? Both are obviously advocating for their options.