Rosalinda;

Is there something that makes your building "green" ?     why did you go conventional first floor and modular second?

Georgia Tom,
The house is very green, in fact running the NAHB tool it rates a high gold.

To start, it has an FPSF, with R30 around the perimeter, and R10 vertical to 4 ft. It has PEX for radiant in the slab and is designed for passive solar with the amount of glass and thermal mass balanced. I have caulked every penetration and every place sheathing meets walls on the inside of all the walls, and foamed wherever it was too tight for caulk, in addition to caulking the joints in the OSB before putting on house wrap. The roof/ceiling is insulated to R50+ in the back half, and depending on which contractor I use will be between R40 and 50 foam insulation in the front half. Though it will have a cathedral ceiling, it is only a 5/12 pitch roof, so it is not an extreme cathedral. There is basically no unconditioned space in the house, except the back 20 feet has some space between the ceiling and the roof, mostly filled with insulation. All the windows and doors are energy star rated. Care was taken in siting the house to disturb the least amount of land, use current drainage features to prevent erosion, and utilize as many of the systems already in place as possible. My energy star rated/evaluator visited the house for the first time today, and he thought I was doing a great job on all the systems, including recycling material and severely limiting what will go to the dump. He even thought I was a bit extreme (in a good way) in my green measures, and also felt that we should get a great ACH based on what I was doing to prevent air filtration, etc.

I built the way I did because it was the only way I could afford to build what I wanted - and I did several years of careful research and pricing before I decided.

I could go on but it is late and I just worked a 16 hour day on the house and am beat. Was there anything in particular you thought was not green? Modular is considered green just from the resource efficiency, and you can stick build green.

I got some of the insulation completed today, but not much. Will work on it all day tomorrow again.

-Rosalinda

Posted By Rosalinda on 05 Jun 2010 01:10 AM
Georgia Tom,


I built the way I did because it was the only way I could afford to build what I wanted - and I did several years of careful research and pricing before I decided.


-Rosalinda

I guess the question is why didn't you go all modular for savings?

I could not get a modular that would allow me to put the ground floor directly onto an fpsf, and I wanted two stories to take advantage of our views over the farm, and Cayuga lake. The main living area is the modular, the ground floor being an at level basement.

Stick building the ground floor unfinished basement using 2X6 construction on the fpsf R21 cavity, with all the plumbing in for a utility room, a future bathroom and kitchen, radiant in the floor, insulated perimeter, all partition walls in and sheetrocked - though the sheetrock not finished and none on ceilings sheetrocked, all the wiring completed in utility room including washer dryer hookups, hot water heater etc, and for possible future bedroom, kitchen, bathroom and sitting room, septic system, new pass through 200 amp service, grading, driveway (re-stoned), interior and exterior lights and receptacles - not sure what I left out - ran under $50 per sq ft.

Hope that answered your question. Interested to hear your opinions.

-Rosalinda

Congratulations on the cost, $50/sq.ft. a job well done with a great deal of effort and time of your own I'm sure!

John

Have had some serious problems, the worst being that my Mom died. This has really thrown me off my stride and I am having trouble getting back to work. I have barely made a dent in insulating the ground floor. It also seems that there are new problems all the time.

On a positive note, the electric is in and hooked up. The roof retrofit is very close to being done - should be finished tomorrow - and the spray foam contractor will be here on Tuesday to start. I went with 7 inches of 2# closed cell for $4400, and they will do my band joist without charge since my husband and I put up the plastic on the walls and floor.

The building inspector came down and is good with all that has been done so far. He wanted to take a look at the truss space in the back half of the house to make sure the straps had been fastened, since the last modular he inspected (different company) had not, but I talked him out of looking since he would have had to push through what is now more than 20 inches of blown in cellulose. I suggested that he could come by on Friday and have the AH crew open up the endwall, but fortunately I had pictures of the stages of construction so he could see that the work had been done to specs. He will be back once all the insulation is completed, and my energy evaluator will also come and do the blower door test. Then is will be sheetrock time.

Having the front half of the ceiling structure ripped out was a revealing process. As it turned out, there was NO cellulose or any insulation over the marriage wall, and whatever insulation had been put in by ManorWood (was supposed to be R38 - 11 inches) was no more than 6 inches deep. So either they did not put in what they were supposed to, or the trip from the factory settled and compressed the cellulose. I foamed the marriage wall and rented a cellulose blower and blew in most of the cellulose we took out of the front of the house to the back part. We now have a very deeply and thoroughly covered back half, though I was careful not to block the baffles.

We have also been going through all the discarded material and pulled out large amounts of stuff that will be put to good use on the farm. It is great that we have only a few trash bags of waste from the ground floor, and were able to recover upwards of 75% of the material from the modular. The biggest unusable discards were the sheetrock from the ceiling and the insulation used at the baffle ends. I would have retrieved the insulation and used it for sound barrier downstairs, but I was away for a week for the funeral etc. By the time I got back the insulation was wet and not usable.

Onward and upward.....
-Rosalinda

Nice house for an excellent price. I'm trying to understand the foundation - I understand a slab on grade with no basement. Are there any footings or beams or is this a uniform 6" monolithic slab?

The foundation is a monolithic slab, 12 inches deep at the perimeter, and 6 inches everywhere else, except under the marriage wall (down the center line along the 46 foot axis) where there are deeper pads under the central supports of the modular, as designated by the modular folks (so they vary in size and depth, the deepest being 13 inches if I remember correctly, though maybe it was 15 inches).

There is R30 vertical around the top 5 inches of the slab and then R10 vertical down to 4 feet, and R5 over poly film under the entire slab. Compacted crusher run then soil. The perimeter foam is backfilled to 4 feet vertical with clean pea gravel with a drainage tube at the 2 ft level out to daylight. The top and 8 inches vertical of the foam is covered with grace shield for ICFs, and then coiled with aluminum flashing from 6 inches below grade, over the top of the foam and behind the housewrap.

-Rosalinda

My energy evaluator came to inspect the insulation yesterday and said it was the best job of installing fiberglass batts he had ever seen. It did take me a long time to complete and I was meticulous about the fit of every piece, but figured no matter how many hours I was putting in on it, it was only going to be done once - so over my 35 year lifetime time frame, it was a short span of time.

The NEXT issue is ventilation. The only ducting in the house is that which vents the bathroom fan and the range hood fan. I do not want to install ductwork throughout the house for an HRV system, but I would like a way to have makeup air that runs through an HRV.

I have fans and windows that will supply fresh air without problem from March through October, or maybe even November, but for the really cold months of December through February, though I can open a window, or put a hole in the wall for make up air, maybe even using one of those one way flow self closing ducts, letting in icy cold air does not seem the way to go. So what are my options?

I have been looking at the Panasonic FV-04VE1 http://snipurl.com/zxdje which appears to be a spot ERV for fresh air. Will this work? Don't I really need an HRV during the winter in my cold climate? Is there any product out there that might work? Has anyone got a DIY solution for this?

My energy evaluator suggests just using an energy star 110 CFM bathroom fan with a 24 hour timer such as this one http://snipurl.com/zxecq (and that price is silly, they sell in the $185 range) and opening a window or cutting a hole in the wall for make up air. This will satisfy the energy star requirements for ventilation, but still looks pretty inefficient to me from a heating standpoint.

Any advice or suggestion would be much appreciated as always.

-Rosalinda

The attached diagram is workable with a manual damper

Chris,
I am not sure how this diagram applies. The house has no ductwork, no forced air heating system, the only exhaust vents/fans are those in the kitchen in the range hood and the bathroom fan.

What am I missing/not understanding?

Thanks,
Rosalinda

Posted By Rosalinda on 01 Aug 2010 09:45 PM
Chris,
I am not sure how this diagram applies. The house has no ductwork, no forced air heating system, the only exhaust vents/fans are those in the kitchen in the range hood and the bathroom fan.

What am I missing/not understanding?

Thanks,
Rosalinda

Does not matter if there is duct work or not, the diagram depicts a dampered fresh air intake, it can be motorized or manual. Everytime you would turn on the range hood or bath exhaust the negative pressure would draw thru the fresh air intake

Thanks for the clarification Chris, I think I understand now. Would there be any way to condition that incoming fresh air so it is not icy cold, any kind of gizmo on the market to do that? Also what kind of damper would work manually on just negative pressure? A standard inline butterfly? A Tamarack Cape Backdraft Damper installed so it lets air in rather than keeping it out?

-Rosalinda

Posted By Rosalinda on 02 Aug 2010 11:13 AM
Thanks for the clarification Chris, I think I understand now. Would there be any way to condition that incoming fresh air so it is not icy cold, any kind of gizmo on the market to do that? Also what kind of damper would work manually on just negative pressure? A standard inline butterfly? A Tamarack Cape Backdraft Damper installed so it lets air in rather than keeping it out?

-Rosalinda

an HRV

With a tight house, you may want an HRV even if it doesn't recover the heat from exiting kitchen and bathroom air.

Posted By jonr on 02 Aug 2010 11:18 PM
With a tight house, you may want an HRV even if it doesn't recover the heat from exiting kitchen and bathroom air.

Not "may want" you will NEED to make up for the exhausting air and an HRV will enable a steady fresh supply of fresh air that can be partially heated on the cold days from the air that is exhausted. Steady is a misnomer as they can be controlled quite easily with on/off cycles, 20 minutes on 40 minutes off! Your everyday activities wil produce a considerable amount of humidity depending on the outside temperature, the colder the the outside temperature the more humidity will be created indoors. A real need for fresh air is required, the indoor intake and the exhaust can be just one vent each just put the return fresh air high up near the ceiling to mix with the indoor air and moderate the temperature as it falls! You may be in for quite a surprise when getting out of bed on a a -15 degree night and see the condensation on your bedroom windows, created by just your breathing!

Just one idea, I'm sure there will be others!

John

Good luck with the build!

Thanks Jon and John,
Yes I definitely need a way to make up fresh air, and though an open window would work, it is not the way I want to go in Dec-Feb!

So, does any company make a spot HRV unit? One that will take in fresh air, mix it with stale/warm air in the room, to take the chill off it, and then release it to the house? Getting fresh air in automatically is easy, I could just use one of those Tamarack one way vents, but warming that air is another issue. Can I use a regular HRV unit, just not have it hooked up to any internal ducting? Would it be effective used that way?

John I like your idea of putting the fresh air return in the peak of the house. With my 12 ft peak cathedral ceiling, that would probably work quite well, since the warmest air in the house will probably be up there. I would just need to figure out how to install the air intake so it is not unsightly, and works properly. Maybe directly though the roof on the south side. With the negative pressure on the east side of the house, prevailing wind from the West, NorthWest, that might cause some issues with a pressure controlled vent.

Things to think about...

-Rosalinda

If resale is not an issue do it right and hire and architect and mechanical engineer working under them with solar and passive experience. Get the design dialed before construction. Their fees with pay for themselves in the money you will save. If resale is an issue it is even more the reason to hire and architect. I recently sold my house design by an architect in the 60s for about 50K more than an adjacent non architect builder designed house with the same specs.

good luck

I would not connect outside air to a return duct - the resulting pressurization will force moisture into the walls in the winter. I'd even adjust a HRV to run slightly negative pressure in the winter and positive in the summer so that all points in the house have the right air flow direction.