My New House Build
 

I finally sold my old house, so now I have the money to build a new one.

Close to Pikes Peak, climate zone 5B (dry), Design Temp = 2*F, Altitude = 8,750', Heating Degree Days = 6,415, Air Freeze Index = 2,500, Wind load = 100mph

IRC 2009 insulation levels & some 2015 mixed in for fun. IPC Plumbing 2006.

Everything has to be permitted & inspected.

I had to hire a Draftsman to format my hand drawn design. Now a Structural Engineer is doing his thing as almost 100 yards of concrete & rebar is needed.

I had to pay $600 for a 2nd soils test to satisfy the county that the 4,000psi decomposed granite (soil) hasn't changed in the last 5 years since the shop was built.
(County has a “Screw the new policy”)

House will be a simple rectangle 30' x 48' with a simple gable roof 9.7 in 12 pitch. Decra steel shake roof panels over batons on 5/8" CDX plywood sheathing.

2 bedrooms & full bathroom upstairs will go inside the framed opening in the engineer stamped attic trusses, 14' x 48'

No roof vents due to fire risk from nearby trees on neighbors property.

I will be using closed cell SPF on bottom side of roof sheathing made by Bayer, will be sprayed in warm weather to help prevent fishy smell.

It supposedly has a built in "Ignition Barrier", but I don't know if Teller County will force me to add a more stringent "Thermal Barrier" ?

If so, I will only use 4" of SPF (supposedly R28) + 3.5" of Johns Manville rock wool R-15 (approved Thermal Barrier)

The downstairs will be a walk-out basement, built into a South East hill facing Pikes Peak.

All concrete walls, 12' in front over stepped down footer (freeze depth) & 10' around rear, + a 24' x 8' retaining wall.

One would think that freeze depth is much more like 6-7' but because of the dry gravel nature the County specifies 32" below grade to bottom of footers, they also insist on 10' deep drain down yard hydrants???

All exterior walls will be insulated on the inside with 2 x 3" 4' x 8' panels of Polyiso foam that I got cheap off of Craigslist from a roof tear off in Dallas Tx.

Something interesting about Polyiso foam is that its R-value is GREATLY dependent on temperature. In example say it's 70*F inside house & 0*F outside, the very outside will be about R-2 per inch & the very inside will be about R-6 per inch.

BBP

Congrats on selling the house! I really look forward to seeing updates on this thread.


This was confusing to me. You don't have roof vents because of a neighbor's trees?

Daox, yep. Big pines. Embers can be sucked into vents.

I bought a small HRV, about 75% efficiency.
Fantech FLEX 100H Heat Recovery Ventilator (HRV) CFM, 0.4 W.C., 50-106 CFM
It will suck stale humid air from master bathroom & return fresh air into great room.

The 3 toilet rooms will all have:
Panasonic FV-11VQ5 WhisperCeiling 110 CFM Ceiling Mounted Fan, White
The makeup air will mostly be drawn in through the HRV, I hope.

Upon running the Builditsolar Home Heat Loss Calculator, air infiltration will most likely be my biggest heat loss. Heating season is about 7 months. No A/C needed.

So I will try very hard to air seal as best I can. The suspect areas are the upstairs framed gable ends, all doors & windows.

I have a high volume lab hood type air pump.
What is a good strategy for finding air leaks, smoke? in cold weather use IR gun?

The spray foam company has agreed to totally cover the top plate areas where the trusses sit on the concrete walls.

BTW, closed cell SPF is very expensive here, about $1.00 / board foot.

Radiant heating system:

It will have 1 high temperature zone, the upstairs bedrooms & bath.
Using 1/2" O2 barrier pexA 8" OC suspended under 3/4" Advantech subfloor including 4' loops up each side knee walls. Only need about 14 BTU/ft2 at 2*F.

Downstairs it will have 3 low temperature zones in the concrete slab (my favorite way) same pexA at same 8" OC. Slab will have 6" of type 2 EPS under & around perimeter.

The heart of my heating system is a Vie$$man 79 gal. Dual coil indirect water heater that acts as a Thermal Accumulator. The Domestic Hot Water will be drawn from the body of this tank and it acts as a buffer tank for the radiant floors.

The bottom coil will add heat into tank from Solar panels or from Burnham RV3 gas boiler.

The top coil will provide heated water for the radiant system.

The slab zones water temperature will be controlled by a Erie Boiler Boss 3000 Outdoor Reset injection pump controller (brand new in box on EBay for about 1/4 of retail)

"
The TAC Erie BB3000 Injection Pump Control with outdoor reset provides accurate control of the water temperature in the secondary (radiant) loop of a heating system, using an injection pump. The BB3000 also protects against boiler condensation by monitoring and anticipating the boiler return water temperature in the primary loop. The outdoor air and loop temperatures are sequentially displayed, along with the secondary loop setpoint and injection pump speed.

Features:
Microprocessor control
Built-in transformer and relays
Real application data inputs
Large, bright display and indicators
Boiler short cycle and low temperature protection
Sure start pump control
Priority override
"

It will control the speed of a Taco 006 used as the injection pump (must use a standard SPC pump) into my DIY cast iron Hydraulic Seperator (mixer) (I copied the design of the Caleffi $$)

http://s3.supplyhouse.com/manuals/13..._PROD_FILE.pdf

It is made out of cast iron tees & nipples & has an air vent on top, fine mesh Stainless steel screen rolled up in middle to elemonate air. Has a strong high temperature magnet in the drain at bottom (needed for ECM system pumps).

All 4 zones will have continuous circulation using 4 Grundfos Alpha pumps set at lowest constant speed (about 3-5 Watts) Each zone has a Tekmar PID thermostat, smart but not WIFI, wired to a Taco ZVC.

The 4 zone valves are 3-way, when OFF (thermostat is not calling for heat) water circulates within its zone to even out hotter & cooler floor areas.

When ON (thermostat calling for heat) the 3-way zone valve directs the zone's return water into the Hydraulic Seperator lower System side port. The zone valve End Switch sends a "Heat Request" to the Erie BB3000.

The injected tank hot water goes into the Hydraulic Seperator top Source port and returns to the tank via the lower Source port.

Hotter tank sourced water is mixed with the zones cool returning water & exits via the top System side port, the BB3000 uses a sensor in this pipe to control the speed of the injection pump.

The upstairs High Temperature zone does not use the ODR controlled water but pumps directly through the Heat Accumulator top coil.

BBP

Just got the county to approve the plans & issue building permit.

Some changes:
Due to polyiso foam R-value dropping by 2/3 at 0*F I changed all the exterior walls buildup to 3" type 2 EPS on outside, them 4" polyiso on inside, where it won't get as cold & drop so much R-value.

The county didn't require any additional ignition or thermal barrier to be applied over the closed cell spf on the underside of the roof sheathing. This is probably due to the very limited access.

R-38 is minimum requirement here (5.5")
I will pay extra to have the 2x6 rafters & the wall top plates completely encapsulated.
This will increase the R-value to about R-50, improve infiltration, & water vapor management.

Good thinking!

-AC

A strange roofing requirement here, ice & water shield (Grace) etc. must be applied at eaves & extending 6' past the interior wall vertical line.

This is to prevent ice dams (which I won't have, no gutters & 9.7 steel roof pitch)

I believe that this is a bad idea, with my closed cell SPF this will create a double water vapor barrier with 5/8" CDX plywood sheathing trapped in the middle.

Perhaps I will file for a variance on this?

Before I backfill around all the footers, I will put down 600' of 1" PEX to use to temper the incoming air to the HRV.

Will build a water to air heat exchanger. Possibly a couple new automobile heater cores in a plenum box.

Ice and water shield does not prevent ice dams. It only provides leak protection from them. This is because the product is fully adhered and provides sealing around penetrating objects. Ice dams still happen even with metal roofs and no gutters.

https://buildingscience.com/document...d-135-ice-dams

In your situation I would probably do a ventilated over roof. Figure 8 in this link: https://buildingscience.com/document...46-dam-ice-dam
It's not the cheapest solution, but the cheapest solution would be a ventilated attic, and I'm assuming you want your attic sealed and conditioned.

Outdoor Furnace Supply has 8"x8" water/air heat exchangers with 1" copper ports.

I would guess stacking about 4 of them would work

My HRV has 5" round ports

Plans have been approved, stamped, & I payed county.

I'm required to build what was approved.

DEnd, thanks for the links.

I read them a few months ago, good to refresh though.

Some reasons why I don't think I will have ice dams:

Bottom of roof sheathing, all rafters, & wall top plates will be completely encapsulated with R-50 closed cell SPF. No warm air from inside the house will get to the roof, no penetrations through roof, Radon & DWV vent pipes exit high up through the rear gable end wall. (Yes this meet code & is described therein)

This type of steel roof, sits up on horizontal 2x2 Batton's, with some air flow under them.

I never had ice dams on my last very similar house & climate zone.

The 600' of 1" pex will be 2 loops of 300' (as A/C said lower pumping energy)
2 manifolds using 1 ECM pump.

Pump will only run when HRV is on AND:
In Summer mode
OR
In Winter mode, when outside air temperature is colder than the loop water temperature.

Loops will be 7-9' below grade behind house & parking area retaining wall.
I expect the return temperature to be about 35*F in Winter & 45*F in Summer.

I will only add glycol if needed.

I will need to find an inline air filter placed before the air/water heat exchanger.

Since you are doing a custom install, maybe think about adding a second heat exchanger after the HRV, for summer use. The reason is you can up the efficiency of the HRV by running the hot outside air through it. This works because you will have a greater temperature difference between the intake and exhaust air streams. with the Heat exchanger after the HRV you can get the incoming air closer to the indoor air temperature or possibly even below it. The reason for tempering the air in the winter before it reaches the HRV is to help prevent core freeze up, and this isn't a problem in the summer.

DEnd, Yes that makes sense.

2 x water/air heat exchangers.
In Winter the DIY HX in the incoming cold fresh air before the HRV tempers the air warmer.
In Summer the DIY HX in the incoming hot fresh air after the HRV Tempers the air much cooler.

In the great room / kitchen (open concept) there will be much more heat loss in Winter compaired with the rest of house, this is due to the 8' x 42" entry door, a large sliding glass door 8' x 8', and 2 7' x 5' windows. I have decided to put down the 6x 185' 1/2" pex loops at 6" on center.

The 3 bedrooms will be 8" on center, the master bath will be its own zone / thermostat with a single pex loop. I'm tired of cold bathroom floors.

It would be nice to have warm floors in the bathroom, but what about running them under the tub at the same time? Stepping into the shower this morning, I thought about how nice it would be to have the shower floor warmed.

Geo, I will run the pex under the tub and under the shower.

I will keep the master bath warmer than the master bedroom, possibly 10-15*F or so.

The thermostats are Tekmar PWM type that learn about and correct overshoot & undershoot.

They have air & slab sensors, which I have never used before.

Micro zones like this can be a big problem with standard boiler installs & even mod-con boilers.

Think about this, the boiler must be sized to be able to keep every room at 70*F at "Design Temperature" (2*F here)

With multiple zones (4 this house) & say it is 50*F outside, then the smallest heat loss zone calls for heat, this could only a few % of the boilers required capacity, and any boiler would "short cycle" leading to lower efficency & early death.

My system has a buffer tank (79 gal.) between the heat source and the radiant zones.
My boiler will always have long efficient burn cycles
(79gal x 8.5# x 30* aquastat Delta) = 20,145 BTU's about 30 minutes minimum for my boiler, and possibly much longer when system is calling for heat.

Sounds like an impressive undertaking! What are you by trade?

Hey Sully01,
I'm a retired software engineer, micro code, power on self tests on many types of disc drives, tape drives, storage controllers, printers.

I have been studying hot water floor systems since I retired in 99.
Have designed & installed 4 systems, this is my 5th.
Learn on every one.

I have made a little progress:

Main lower level of house walls have been poured: 8" concrete x 10' high, a 30' x 48' rectangle walk out basement.

I had the windows bucked in so that windows & doors sit into a 5.5" x 1.5" recess all around on the outside, so if they ever leak water goes to outside.
Windows & sliding doors are Andersen Series 100 Fibrex

Attic trusses are on site and I have added the 16" gable end overhangs.

The gable end trusses have the 2x4's laid flat, on them I glued & shot 8 penny nails 1/2" CDX plywood, primed all seams with Glidden Gripper, taped with 3-M all weather tape,

Next layer is 30# roofing felt,

next layer a drainage plane of 1/4" Benjamin Obdyke Home Slicker + Typar,

next layer is 1/4" 4x8' sheets of James Hardie exterior cement board with all seams taped with cement board mesh tape,

next layer is a base coat of Styro TuffII synthetic stucco,

now they are ready for the crane to hang, but 1st I have to backfill around sides & rear,
before that I have to have the footer drainage system inspected,

then install the 1" PEX water line in, the 4" sewer line out, & the 200 Amp power line in,
the 1,000 gallon cistern & float switch wires,

inside the cistern I will put a 300' of 1" pex to be used for cooling upstairs in summer.

Whew! just getting started

Congrats on getting started.
We need picture!

Awesome progress! Ditto on the pictures. :)

As my computer crashed, I'm on a public library computer.
All my photos are on my Iphone.
I selected 5 pics on Iphone & am in VERY SLOW process of them hopefully uploading,
seems to be choking at 2 bars signal strength.

Hope these pics work

1st pic is above rear of house looking East, the front door in middle is 8' high, the windows on either side are 7' x 5', the sliding door on the right (South) is 8' x 8',

the rear (West) bedroom window is 4' x 4' egress,

the front (East) 40% 12'-8" wall is on a 32" step down footer, as this dirt (haha) is decomposed granite (small rocks) and dry, this is all I had to go down by IRC code, the space inside the wall gets 7-8” thick type 2 EPS

2nd pic shows the 27' retaining wall 10' tall with a buttress on back side (dead man), on front (East) side will be parking & BBQ area by slider.

3rd pic shows the North wall buttress, required by my Structural Engineer due to 48' wall length & 8' of back fill.

4th pic shows the front (East) gable end (bedroom) with a 6' x 6'-8" sliding glass door opening out to a 12' x 20' balcony/carport.

The lovely purple color is what I got when adding dye to the Styro TuffII, not what I was shooting for, so I call it a base coat.

5th pic shows the rear (West) gable end during assembly, has a 4' x 4' slider for a 2nd upstairs bedroom egress.

BuffaloBill I like your work Im planing my first build for next year using ICF's.

have you considered using rigid insulation on the outside of the basement ? it would be first on my list so thought I would bring it up.

I agree with Martin Holiday's + and - recent comments on this Greenbuildingadvisor.com

My inner layer is 4" of Polyiso foam which can't be in contact with earth (gradually absorbs water)

http://www.greenbuildingadvisor.com/...-basement-wall

http://www.greenbuildingadvisor.com/...ers-spray-foam

Trying to upload latest pics on cell phone is not working, hung, 2-3 bars signal strength

got this message "your submission could not be processed because a security token was missing"

I give up

I found that I could upload 1 pic at a time

Pex Layout in MBR

1/2” Pex-A. Mr Pex brand, nice flexible stuff.

4 loops, 165’ each, 6” on center, Counter Flow pattern.
This allows for very low pumping electricity usage due to low head loss.

4 heating zones in house, each has its own Grundfos Alpha (about 5 Watts on low)
Continuous circulation in heating season, about 8 months a year.

Master Bath along North wall is its own zone, 1 loop, so it has its own thermostat so I can keep bathroom 15* warmer than Master bedroom, shower has a heated seat.

Pex manifold kitchen / GR

6 loops, each about 170’

6” EPS that is under 10 mil black plastic under pex

Decra Shake steel roof going over battons & counter battons over Ice & Water Shield underlayment that is over 5/8” CDX plywood roof sheathing

R-49 closed cell SPF on underside of roof sheathing. Product is Bayseal which has an intumescent within it + 20 gallons of their intumescent paint sprayed on bottom.

Pic. showing attic trusses that support the roof and frame the upstairs 2 bedrooms & full bathroom.

Front of house with unfinished 12’ x 20’ balcony / carport.
Front bedroom has 6’ sliding glass door onto balcony.
Parking area for 2 cars along retaining wall.

I have decided to cover the inside wall and gable ends with R-15 3.5” Roxul rock wool reaching an R-40 total.

The downstairs ceilings are 10’ high.
I’m using 10’ LSL’s which are a manufactured 2x4
They cost more but are straight, good luck getting a straight 10’ lumber yard 2x4

I got the concrete slab poured for the downstairs floor.

1440 ft2 full floating with 6” of type 2 EPS under it and 7” around entire perimeter.

Old sub-contractor used young labor & did a nice smooth job, he said that the rich mud was easier to finish. I got it done about a month before Winter set in.

About 5" thick on average, high strength 5,000 PSI & double fiberglass
(which are now smaller strands than they used when i last did this)

Ran a 1/2" rebar (#4) all around perimiter about 5" in from edge.
The heavy gauge 6" x 6" remesh in the slab was handy for attaching the pex with zip ties.

I tried to run the 1/2" pex at 6" on center but with all the sweeping turns it averaged 7”

I reduced the doorway heat loss issue, to some extent, with EPS foam between slab & outside concrete wall and a 2" x 12" PT board on top to bridge the gap.

The 2x12 at the outside edge sits on 1.5" angle Iron that is attached to the inside of the 8" concrete wall with 3/8" RedHead anchor bolts, the inside edge of the 2x12 sits on top of part of the concrete slab that was allowed to run under it for a few inches, very secure.

I will need to dress it up on top with something that won't conduct too much heat out.

Upstairs 672ft2 is heated by Pex suspended under the 3/4” Advantech subfloor.

This heat transfer from the Pex via convection & some radiation to the subfloor is less efficient than conduction in a slab & the water temperature needs to be about 40*F hotter (no good for solar or a heat pump)

Most is spaced at 4” on Center and is 2” to 6” below subfloor and works mostly by convection.

Pic of Pex under upstairs subfloor