|By Mike & Carolyn in Smithville, MO on 8/13/2008|
Hello, welcome to Kansas!
I have been reading your posts on insulation and construction questions, and while I'll start by stating that I am not an expert on any topic, I thought I'd share some info on what we’ve learned. I am a Realtor in Kansas City Missouri specializing in new construction. (Background in architecture… go Wildcats!) You will need to check the Kansas Codes to see what is required in the way of air barriers and siding. The Kansas City, Missouri codes were just updated June 1st of this year; my guess is that they needed something to do since the building industry has slowed to a crawl and the recent additions would increase the price of homes thus increasing the fees they could charge the builders (especially when they had to re-master all their plans). We are now required to install Tyvek housewrap for all building (permits pulled after 6/1/09), low-E windows are a requirement now as well as egress window being required in full basements (non-walkouts).
Our permit was pulled before this change so it does not impact us. We insulated with Icynene and while we are not moved in yet (we are finishing up drywall) it seems to be doing the job. Our construction project is small; we are building our quest house first (850 sq ft space above the detached garage). The insulation job was large. We insulated EVERYTHING. The down walls of the garage (ones that were not concrete), the garage ceiling because there is living space above. The exterior walls of the house and one interior cold wall that backs to the staircase to garage. And we had to insulate the entire ceiling because the rooms are vaulted.
There were not that many companies that did Icynene, but I did find three and the bids ranged from $4K to $7K. The company we went with did have the lowest bid and I got him a little lower by telling him I just could not afford it right now. It also helped that I was paying cash at completion so I had more room to negotiate. I simply did not have more money to give him. It was the end of the year and I guess they needed the business because they came down.
Icynene does not increase the insulation R-value, but does act as an air barrier. We will share if we see any savings through this winter and take note of any cold spots. *** Take note -– if you go with foam, make certain that the crew does a complete job trimming. If they overspray, they will need to trim the foam so it is flush with the studs in the walls and ceilings. PLUS they will need to clean off any places that the foam gets on the studs or it will impact the drywall installation… if they don’t do it then you will be... so inspect their work before you approve the job.
It is my opinion that with foam insulation a housewrap is overkill (not that we have an option in Kansas City, Mo now). Your decision should also take into consideration what type of siding you will be using. If you’re doing the stick construction and the siding is the wall skin and you're not using foam a housewrap will help… if it’s installed correctly (it needs to be installed correctly to add any value and not cause problems). If you are using lap siding that requires a base wall to attach to it probably won't add much since you will already have two layers (the lap siding, the sub wall) before you get to your insulation. If your exterior will be stucco, you’ll want to use the stucco wrap. On the cost side, foam is a ton more money than housewrap. And you may be able to get the same effect by using Tyvek and fiberglass. (Blown in or batt... I'm not convinced that blown insulation will not settle over time... only my opinion.)
On the construction type, you’ll be hard pressed to find newer construction methods. Most here stick to stick construction. I’ve read a ton on the insulated panels and even watched a house go up using them on TV, and while I’d love to be involved in the build of one, I have never seen one being built in my 10+ years selling and building houses here.
Have you researched heating systems yet? Will you be using a ground source system? We are looking at it for the main house, but I keep choking on the cost. Latest bid was $26K for up to 4,000 sq ft. plus we will add radiant heat in the basement floor slab. Decisions, decisions…
Hope this helps and happy mowing.
Mike & Carolyn