Building a Honka log “pretty good house” planning - thoughts on hvac, ventilation and roof
We are planning a Honka log house. 2 stories, 1750 sq ft. The solid Finnish pine logs perform really well, people say they provide superior air quality and behave as thermal batteries / but I can't tell how close to a passive / pretty-good-house their R value brings them. I'm hoping to get some feedback and possibly alternatives on what I'm thinking. At 204 mm leakproof & sealed logs with thermal battery adjustment. i suppose the R value is about 11? Feels little but I fear I'm missing eg how it behaves in warm weather. I'm really not feeling adding extra insulation as per Honka, but I don't know if that impacts/cancels any of the below.
The build is in Three Rivers, CA - it gets hot and dry there 4 months a year. Winters are chilly but not Chicago :)
I am told the logs breathe, but I'm still really loving the idea of a passive-like ventilation with an ERV (I totally got sold on Zehnder) I have my doubts if it's overkill or "pointless" / can't find information using it in a log house.
For cooling, it'd be a mini split system. Mitsubishi probably.
Finally, I'm thinking of a metallic roof with thermobuilt insulation. Did consider a green roof but I'm not sure we'll have the room in the budget. Any alternatives? At approx 1200sf I'm hoping the roof budget to be as low as possible / below 20k.
I'm also trying to understand how any of this can help the appraised value of a house (especially the one done before the construction loan is awarded and that number sets what we'll get). See what's a good bet and what a waste of money (for the appraised value and impact on quality of life)
I realize these are many questions, Im a total newbie - I appreciate any input.
Wood is somewhere in the range of R1 per inch, so a log house wouldn’t be anywhere close to Passive house in terms of either airtightness or R value. We would be happy to help but as is there are too many questions in here and it would be difficult to really iron out any of your individual questions without getting muddled, but I will give you some bullet point answers to start –
More than logs ‘breathing’ is that they typically leak air unless some sort of air barrier solution has been figured.
I would add insulation, I would not build an R11 house myself.
I agree that a Zehnder is sort of pointless, that is a top of the line ventilation system for helping achieve performance levels that would be difficult to achieve with a log house. The added money would be better spent elsewhere I think.
Minisplit heat pumps are a smart idea for efficient heating and cooling.
I don’t know about thermobuilt insulation, but I would say a metal roof is always a great idea as they last much longer than shingles.
Sorry we can’t help more, for the moment I suggest you dig through our building guide as a lot of your questions on best R values, air tightness, Ventilation equipment, roofing and heat pumps is all in there. You can search either from the category menu or in the search bar. From there if you have questions we can for sure help, just try to break them up so they are easier to address. Best of luck!