# Feasibility of Courtyard Greenhouse?



## Bellaforte (Oct 12, 2012)

Ok, bear with me here: I don't know a ton about home construction, but I'm in the research stage for the acreage we plan on buying in 1-2 years, and one of my research projects is basic house design. 

One of my husband's favorite designs is the Chinese (and Greco-Roman_ U-shaped house with the central courtyard. I like it, but it feels like a waste of space/materials/construction to me. 
I was already thinking about a lean-to greeenhouse attached to the north wall of the house, however. (Think this or the first attached picture, but with a door from the house, and probably dug down a few feet into the group rather than sitting at the same level of the house)

I was thinking, though.... why not use the courtyard as a greenhouse? We live in the Southeast (north Georgia) so it'd have to have a retractable roof for summer (because holy HELL the amount of heat that'd build up in there), but in the winter, it would theoretically lend heat to the house while also receiving some from the house. 
My very basic idea is something like this or the second attached picture, although obviously a smaller and simpler house.

I realize we'd have to do some seriously fancy footwork to ensure the foundation were appropriate, etc etc, but can anyone with some construction experience tell me if this is a reasonable idea, or if I'm missing something vital that I'll deeply regret?


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## Solar Geek (Mar 14, 2014)

Not an engineer or builder but the courtyard issue would be more than just heat. Assuming you are using most of the courtyard for the greenhouse, I foresee you need to resolve the following:

Not enough light due to the surrounding structures of the home, 

excessive moisture build up (as in any greenhouse but especially so without any outside air movement due to the surrounding house structure),

Too many chances for bugs entering your home from the plant materials, and 

Movement of plant materials each year dirtying up the house! Wheelbarrows, seeding trays with dirt, end of the season plant wastes needing to be composted or disposed of.

I start plants in my basement each year for a 7500 sq ft garden, and also keep smaller trees both in the house and basement under LEDs-- Meyer lemons, Navel orange -- and just maintaining them and starting the seeds each year is MESSY. 

We are building a greenhouse as the south bay of a "3 car garage" which will not be a garage but an AG building. Similar to your lean-to plan, but specifically designed for movement into and out of my garden to which it will be attached by fencing and a concrete apron off the south bay to facilitate plant and garden produce movement in wheelbarrows.
We are planning on standard windows only tons of them, as well as solar shades to cut the sunoverload in summer or winter; also a mini-split for heat in winter (we are in Central WI), and a glass garage door (insulated glass) to make moving large container trees in and out during the warm season.


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## melli (May 7, 2016)

Actually, I've been in a house similar to what you have in mind... modern Frank Lloyd Wright inspired home. Although, the center block wasn't a greenhouse per se...just had a large bonsai type tree growing in it, surrounded by gravel. And the whole center block had glass walls, except where roof supports were needed. Kind of cool, as one had a view of court from anywhere in house. Then it had a water feature that appeared to go under center block.....I live in a temperate zone, and solar heat isn't a huge issue, but heating the home must have been insane. We are talking half the house seemed to have glass walls!
I suspect heat and moisture dissipation would be an issue in your case, but resolvable with shading and ability to open roof windows (have a gabled glass roof over courtyard). 
I agree with Solar Geek, in that getting light to center block would have to be addressed. Having south side glass walls would help. 

I think it is totally doable, but you better have deep pockets. Glazing is pricey. One home I visited, had floor to ceiling glazing just on south side wall (50') overlooking ocean (stunning). 100k just in glass. Probably double that now...


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## Bellaforte (Oct 12, 2012)

Solar Geek,
Ooooohhhhh good points!!!!! I hadn't considered the humidity buildup or the bugs. Oof. And those are major problems here. 
What if we did it U-shaped instead of all the way around, so the greenhouse had an entire wall that could open to the outside? Do you think that'd mitigate most of those problems?
(See attached pic of SUPER rough layout idea I sketched in court yesterday)

Melli,
Good point on glazing. We're definitely assuming this house is going to be expensive, but we're lucky that we _should_ have some resources to help, plus in theory this place will get passed down along at least a couple of generations. (Looooong-term plan is to build this place, raise the kids in it, then build another smaller 'retirement home' at the other end of the property and give the big house to whichever of the kids wants it when they grow up)


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## Bret (Oct 3, 2003)

If you see it, you already have it. Good work. Keep moving on the trail. Good tweaking ideas are coming like above. Always inspires me--the collective knowledge and experience of HT Talents.


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## Fishindude (May 19, 2015)

Neat design for a real green thumb type person, but it is not a very efficient use of building material. Here is some simple math:

Your floor plan above - Approx. 2,788 SF of living space, 328 LF of exterior wall. You have exterior wall around perimeter and adjacent the courtyard.

Optimal floor plan - 53' x 53' square provides 2,809 SF, almost same square footage with only 212 LF of exterior wall.

The courtyard design uses 116' LF of additional exterior wall surface to provide the same amount of living space. Every lineal foot of exterior wall requires; foundation, wall framing, insulation, interior finish, exterior sheathing and siding or brick, fascia, soffit, gutter, etc.


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## Solar Geek (Mar 14, 2014)

Fishindude said:


> Neat design for a real green thumb type person, *but it is not a very efficient use of building material*. Here is some simple math:
> 
> Your floor plan above - Approx. 2,788 SF of living space, 328 LF of exterior wall. You have exterior wall around perimeter and adjacent the courtyard.
> 
> ...


Bellaforte, what he said and more. 

I like the u-shape if cost is no object. BUT again you *need to have the U opening South facing to use passive and agressively passive solar methods for the plants.* You still will not get all day sun with the building surround.

My sister built a very similar home to what you are proposing first in Michigan with a garden and patio in the U and then in Florida with a pool/lanai layout in the U. Too much sun and Heat into the house was a huge consideration for both locations - they invested in heavy drapes but I would have done solar shades as we have here. Humidity was a given in both locations so they used tons of A/C. Both homes were lovely and we all make our choices. They did not attempt a greenhouse. 

We, like you are planning, had built (by others) a "generational house" made with ICFs, fully passive solar- aggressively so - and with 18KW solar panels and Solar thermal for domestic hot water here in 2012. It was our 16th move so we had some building and house issues experience. FWIW, I think you can do the U shape if cost is no object (see above), it will be lovely but you will struggle still with the bugs, humidity, and loss of required length light hours for much of the year. 

Also, I forgot to mention, for winter growth you will have to supplement with *artificial lights as I am doing in our basement right now with winter greens. 12+ hours per day, full LED lights*. Do you want those shining into all areas of your home? I also use them for spring planting as the sun isn't strong enough to really get the plants going till mid-May or later.

As with smells from animals and barns too close to a home, there is a reason most greenhouses are not "part" of a home. But it will be lovely in the dead of winter.


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## Bellaforte (Oct 12, 2012)

Ooof. ----, you guys, you're killing me with your logic and knowledge and stuff 

Sigh. Better to hear it from y'all, though, than to start building and find out what a problem it will be. 

*whines* I don't have to like it, though.


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## Declan (Jan 18, 2015)

a center courtyard means you will have a ton extra roof to put down and eventually replace. Just stick it on the side.


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## dyrne (Feb 22, 2015)

Unless this is all to be under roof, if you do end up encasing a courtyard with house all around make sure you have somewhere for the water to drain from the center so as to avoid a central swimming pool. If you do a U shape (not a bad plan) make sure to grade and drain that well also.

I love the _idea_ of a central courtyard. If placed on the side of the house instead, as stated I would not normally consider a greenhouse area except on the southern exposure.


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## Maura (Jun 6, 2004)

That is an atrium. Some plants will grow very well in it. Basically, house plants. I think for a real greenhouse you would want a U shape house or put it on the best side of the house. For us in Michigan that would be the south side.


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## learner-57 (Oct 29, 2016)

Instead of a traditional "U" shape with 90-degree corners, you might consider 60-degree corners where side "arms" join "base" of "U". Aim opening due South, and you get a lot more daylight. Extend greenhouse beyond ends of side "arms" so you have one wall that extends whole width of southern exposure as your main vertical greenhouse glazing and the roof over greenhouse as only other extensive glazing. For greenhouse glazing, definitely avoid glass and go with dual-wall polycarbonate sheets for greenhouse. Moisture, mold, and bugs are all great reasons to keep house and greenhouse separated. From perspective of house, the greenhouse is "outside" so you'll need vapor barrier and all the rest along both sides and end of both side "arms". Ventilation of house should NOT come from greenhouse, although it'd be best to exchange heat from cold outside air coming into house with greenhouse, but without allowing mixing of greenhouse air and inbound air for ventilating house. My 2 cents. 

Also, strongly recommend greenhouse be "sunken" down in the ground a few feet inside that "U"-shape or half-hexagon-shape. Also provides more interesting views from inside house, and makes it easier to get more height inside greenhouse without having its roof towering over home. Use simple solar-powered fan controlled by thermostat to push hot air from highest point under greenhouse roof down into a "climate battery" as many are now calling it (basically drain pipe burried and used to push hot air down into ground a few feet below greenhouse where it can heat the dirt. Can really help keep northern greenhouses much warmer at night and even over winter. Along "back" wall of greenhouse (up against house wall) place 30 or 55 gallon containers (food-safe quality barrels or drums) and fill with potable water and suitable amount of bleach to keep it safe to drink. Kills two birds with one stone: above-ground storage of potable water for emergencies, and thermal mass for storing heat which will be released back into greenhouse overnight, another "heat battery" if you will. Yet another 2-cents of advice you didn't solicit. Sorry. Good luck with your planning and design.


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## learner-57 (Oct 29, 2016)

It's been pointed out to me that my last comment was very obtuse about the angles involved and the value of same. Mea culpa. :facepalm:

Looks like this: \_/ 

where interior angle is 120 degrees, exterior angle is 60 degrees, and South is up on the page (North down, East left, West right).


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## Bellaforte (Oct 12, 2012)

learner-57 said:


> It's been pointed out to me that my last comment was very obtuse about the angles involved and the value of same. Mea culpa. :facepalm:


I actually understood you 

\_/ versus |_|

Thank you, though!


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## wy_white_wolf (Oct 14, 2004)

Fishindude said:


> Neat design for a real green thumb type person, but it is not a very efficient use of building material. Here is some simple math:
> 
> Your floor plan above - Approx. 2,788 SF of living space, 328 LF of exterior wall. You have exterior wall around perimeter and adjacent the courtyard.
> 
> ...


 Not necessarily.

South wall for the courtyard can just be exterior wall with lots of windows. It is still load bearing. Roof simply has lots of skylights. Walls between it and other living spaces then are no different than other interior walls or interior glass walls. Real easy to do with a slab foundation. Stain the concrete in the courtyard area like a patio and raise your plants in containers/raised beds. Not that much more expensive.

The inside courtyards that I've seen have not had a problem with bugs in the house. They've actually had a problem with beneficial bugs not being able to get to them. Plan on hand pollenating everything that usually requires bees, bugs, or wind.

WWW


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