Old/ New construction considerations
Are there any insulation/ HVAC considerations to keep in mind when planning an addition to a poorly insulated 100yr old home?
New construction would be well insulated, probably spray-in foam. Old, existing exterior walls have loose fill that was blown in 20+ years aga and has presumably settled to about 1/2 wall height (9ft). there is about 4-6″ of loose fill in the existing attic (single story).
I am leanign towards a new, separate gas fired furnace to support approx 900 sq ft in 2 story addition rather than relocating and upgrading the existing HVAC unit to service the entire house and addition. Mabye I’m wrong about this but I am assuming that it would be more economical to do it this way as opposed to re dooing a lot of existing duct work.
Connection to the existing structure would provide for a 5-6ft passage way opening on the first floor and 3-4ft opening to a stairway leading to new second floor.
Please comment on my intended means of providing heat and if any special considerations need to be considered given that the old house leaks like a sieve and the new construction would be tight as a drum.
J
Replies
First, how do you know tyhe wall have settled to half there original height? Second before, or as part of the construction of the addition why don"t you correct the insulation problem? Third, if you hire a good GC he will have the answers to this problem. If you are acting as the GC, contact an hvac contractor and he will compute what you need.
First, how do you know tyhe wall have settled to half there original height? Based on observations made durring renovation to the existing structure. where plaster and lath were romoved, new insulation was placed. (10% of exterior walls.
Second before, or as part of the construction of the addition why don"t you correct the insulation problem? Several reasons: Plaster/ lath interior, 90% of the walls were refinished within the last 6 months, trying to save on costs..i'd be more inclined to add additional insulation in the attic vs. walls, I have been living in constant construction dust/ debris for 2.5 yrs and any additional work to the house will be on hold untill there is enough space to be able to stay out of work zones. (small 2 bedroom house)
Third, if you hire a good GC he will have the answers to this problem. If you are acting as the GC, contact an hvac contractor and he will compute what you need. I intend to hire professionals to install the new HVAC sys (permit required) and also to GC myself. The reason I asked these questions here is I want to know what to expect before they tell me!