Timber Frame Barn - Critique My Plan

[johnhroberts1993]

First post here, please excuse the ignorance. If any of this seems ridiculous, bring me back down to earth.

Recently purchased land in Lincoln County, Maine. In the process of getting out of the service - after 8 years and several trips - due to medical complications. I will have some time on my hands here soon and would like to stay busy by building a structure to live in for the foreseeable future.

What I want:

36'x48' Bank Barn
1st story (basement) will be open floor plan for storage/work shop. 2nd story will be an open floor plan for a living space/kitchen/wood burner with an enclosed 12'x24' bedroom, bathroom, and closet. 3rd story will be a loft for additional storage.

Basement will either be poured walls or concrete blocks on a slab. 2nd story flooring will be 3x6 or 4x6 T+G roof decking (if an engineer will bless off on live weight loads). Loft will be 1x6 T+G.

Question: With enough R value in shell/roof - do you believe radiant heat in the basement and a wood burning stove on the second story would sufficiently heat the barn in the winter? Is there any way for me to direct the hot air from the basement to the second story?

My inexperience in this field (Timber Framing/General Construction) is probably pouring out of this post. I am expecting to receive some good redirect questions about my preferences. Let me have it.

For added context, I will be attending a timber framing course later this summer. I will refine the plan at that time. But off the bat, is there anything that jumps out as being unrealistic? Hope to cut and mill the frame myself. Timeline for project is to have it complete three years from this fall.

Thanks much.

[Sod saw]

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John,  If you have a dusty project in the basement and that basement is connected to the upper floors by air ducts to heat the upper floors, You may be introducing that basement dust throughout the whole place.

On the other hand if you have a heat pump in the basement providing heat to basement radiators,  Can that same heat pump have 2nd and 3rd zones for the second and third floors respectively?

A passive house design would require minimal heat pump as the insulation value is quite high. 

Perhaps a stress skin shell outside of the posts and beams could provide that level of insulation.  You are near the coast so the bitter north temperatures are not an everyday concern.

Good luck with your project and class.


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[johnhroberts1993]

Sod,

Thanks for your response. I just did a deep dive on multi-split heat pumps for 3-4 zones. I initially wrote them off because I did not want a bunch of lines running across the exterior. However, I think there is a solution that would allow me to set semi-centralized wall/ceiling splits (for second story and basement) by running the linesets through the interior wall that splits the bedroom, bathroom, and closet.

When you say stress skin, is that term specific to SIP construction, or used more broadly for any type of exterior shell built outside of the frame, like wrap and strap?

[Sod saw]

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John,  My initial thought was about using SIP as you wondered.

However, any amount of good quality insulation (thick enough) outside of your posts should help with your goal.  we are getting ready to start a foundation for a house, near here, where the walls will be R60.

The foundation and basement will have 10 inches of foam board outside of the block walls below grade.

Having said all that, more important than insulation and R value numbers is the amount of air that can blow thru these various walls and ceilings, etc.  Many building requirements in many areas of the country require a blower door test to show how much air can pass thru cracks in the shell of the building.  The goal is to have as little pass thru taking heat out as it blows thru.

Check out the "Passive House" requirements.  Yes there are standards to meet Passive House certification.

However, now we get into stale indoor air and the build up of indoor moisture and carbon dioxide (from breathing people) and other chemicals that may off gas from furniture or the building itself.  As a result we now have, entering from stage left, the advent of whole house ventilation and its associated heat exchanger to provide fresh outdoor air without the loss of all that expensive heat.

All of this should be designed by some one who understands the actual math for each individual building. Many Architects and Engineers do not understand this yet, especially with a post and beam frame,  but many are starting to get it.

Yes you can run heat pump lines in interior walls and the heads can also be mounted on interior walls due to their fans running most of the time.  With conventional forced air furnace or hot water boiler radiators the heaters within each room should be on outside walls.

Have you scheduled a class yet?  Some are talked about here on the forum.




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