Walipini in north central Massachusetts (5b).

I'm starting this thread both to share information, and to encourage myself to keep this project moving forward.  Hopefully in the future, it will turn into a status update after we build it.  (In case it matters, I'm also going to be posting the same info on my recently started garden blog. A dupe of this post is schedule to post there tomorrow.)

History Behind the Project:
- I first read about walipinis on Treehugger a while back.  Knowing I'd eventually want to buy a forever home in MA, I thought it might be a good method to extend our 179 day growing season.

- We moved here in spring of 2016, and bought our home on March 3, 2017.  While house hunting, one thing on my want list was a backyard with reasonable south facing exposure for the walipini.  My thinking was if we did get any neighbor resistance, it would be less likely in the backyard.  Our hardiness zone is 5b.

- Although our urban lot is very small, the orientation is near perfect (SSW), and the shape of the house along with the cellar stairs exit had promise as well as to placement. (Door area seen on the left side in the listing photo below.)  The neighboring trees to the south and west are all deciduous.
 

Recent Progress:
- I am a lazy gardener.  I don't mind doing a decent amount of work to get a project going, and the idea of building the walipini so I can step right into it during our snowy winters from our cellar was too delicious a prospect not to research further.  Not only would the house help insulate and wind break the north side in winter, but the walipini might help with heating our SW corner office where we spend a lot of time in colder months.  I knew there would be moisture and air circulation considerations, and that is part of what I'm looking into now.

- I am also researching various methods of assistive heating of the walipini itself by building a compost pit along a portion of the walipini.

- There are other aspects I'm still researching, and I'll get into those over time as time allows.

Recent Progress:
- I have looked into the local code as it pertains to outbuildings because the code only seems to consider greenhouses (walipinis aren't even listed) outbuildings, even though my current plan is to build our walipini as an addition.  There's a certain size I need to stay within before the town will make a big deal about it and consider it a commercial addition to our property because they assume a certain size greenhouse will only be for commercial use.  (I may eventually try to start making some funds from our gardens overall, but that's a further down the road possibility.)

- I'm also trying to find possible code related rules regarding additions, in particular because ours will be a permanent above and below ground addition.

- I've been loosely sketching the footprint, as well as possible heat sinks and water containment.  Now that I cleared off my drafting board, I hope to start working a scale drawing for a base that I'll use and adjust over time.

- I'm also looking into various water catchment/retention systems, such as dry cisterns and water wall insulation methods filled by run off from our roof.  Our roof currently is asphalt shingles, but we hope to put in a metal roof within 5 years, mostly because the last update to the rear side of the roof is just about needing a replacement anyway within that time frame.  I only yesterday started specifically looking into sand filtration systems for the possible dry cistern.

Moving Forward:
- I will keep researching about greenhouse add-ons as to building science and how much, if any, town code relates to such.  I have found this thread here about moisture considerations with an add-on greenhouse where I've learned very useful bits to consider.

- This project also ties into overall plans in the works (and some started last year) as to regrading around the house, as well as possibly adding a dry creek bed with swale underneath for the 5' strip along the west side of the house that will lead into a rain garden on the upper portion of the sloped front yard.  All these aspects I'll post about later as I figure out how they might best work together with the walipini.

- I need to decide whether to regrade for the short term in that area, and later start digging down for the walapini.  I'm not sure if we'll have the budget for the structural aspects this year, and don't want an uncovered pit just sitting right next to near a third of our rear foundation even if we do install guttering and a rain barrel on the roof in that area (we currently only have a gutter on the longest edge of our front porch, where we put our first rain barrel).  We still have other new old house expenses that are higher priorities (like the ongoing process of adding insulation to our attic that had none at time of purchase.)

I think that's the dead basics for now, please stay tuned over time as I report how things are coming along.

Feel free to post questions and tips.  I will do my best to respond to both in a timely fashion.

Thanks for sharing this dialog of your project!  Looking forward to hearing about your progress - good luck with it!

Awesome project!  So the walipini will take the place of the bump out with the door on it so that you can walk into the greenhouse from the cellar?  Sweet!

Is the house foundation cement or stone?  I'm not sure if that matters but it might.  Once you dig out the earth on the outside of the wall, that foundation wall will have to stand up straight all by itself.  I think that's likely since it was built that way before they backfilled.  But if it's stone and the mortar has eroded over the years it may be worth checking.

How deep will the South wall of the walipini be?  Remember you may have snow shedding off both the roof and the walipini that will block winter sunlight.  Drawing up a side view of the greenhouse showing sunbeam lines in December with snow piles may be instructive.

Remember that glass roofs loose heat. I have observed that higher latitudes [I am at 47.25] you don.t need a glass roof. it over heats in the summer and cools too fast in the winter. My greenhouse is 16 feet deep and the su reaches all the way to the back in the winter and I only use the front third in the summer for tomatoes and basil.  So my recommendation is to dig in at the level of your driveway so that it is easy to bring planters in and out and have an insulated roof with vertical glass which is easy to drape to insulate on winter nights.  I have my zone one garden in 25 gallon barrels that I put on the north side of my greenhouse overwinter and bring them out after freezing stops. This is good for ornamental and herbs which you would like to have at the front entrance.

Mike Jay wrote:Awesome project!  So the walipini will take the place of the bump out with the door on it so that you can walk into the greenhouse from the cellar?  Sweet!

Is the house foundation cement or stone?  I'm not sure if that matters but it might.  Once you dig out the earth on the outside of the wall, that foundation wall will have to stand up straight all by itself.  I think that's likely since it was built that way before they backfilled.  But if it's stone and the mortar has eroded over the years it may be worth checking.

How deep will the South wall of the walipini be?  Remember you may have snow shedding off both the roof and the walipini that will block winter sunlight.  Drawing up a side view of the greenhouse showing sunbeam lines in December with snow piles may be instructive.

Yes, forming the base around the walk out is the plan.  The foundation is cement (1935 build).  I'm hoping that will work in our favor.  I have been trying to look into expansions of cellars (as when an addition will be above), but I lack the proper vocabulary it seems because the results I keep getting (for cellar or basement) have been lousy so far.  I've only tried twice, though.  I'm thinking we might need to do a secondary base block row for support, which I've seen done when folks dig down inside their cellars to add height.  

From what I roughly measured, the base of the poured concrete stairs currently going out are roughly 6' from the wood sill of the stair shelter.  I honestly do not recall at the moment how tall the house face is from ground to roof.  Still, right now I'm thinking at least the cold sink would be 6', possibly a bit less. (Image showing a cold sink for example, not scale--also not my sketch.)  

I've been toying with the idea of digging a small area inside the cellar wall near to that doorway to see when I might stop finding block to get an idea of seepage and such.  (I've not yet been able to find original plans for the home to know for certain how tall overall the cellar walls are including the below ground portion.)  I've been trying to research what will happen if I grade the walipini floor away from both stairs and the south wall into a cold sink drop that would possibly have a walk way over it, and possibly having that be part of another dry cistern system because I believe it will be too low to tie into the other I am considering at present and so would require a pump to drain if I was to tie it into that which I'm trying to avoid.  I've also been looking into some notions regarding flashing the foundation to guide water away like the image seen below (I don't know how to make attachments show up anywhere other than the bottom of posts).  

I share your concern with snow shedding.  I know if I run the roof from just under our current roof edge, and take the steep angle downwards since I don't intend the footprint to go out that far, it may help (along with the south facing) in keeping the snow moving along.  Even when I draft the side view, it won't be a guarantee that the snow will move, no matter how close to the optimal angle I manage for best solar collection  I have been looking into the few walipini structures in NE to see how they handle snow loads in general, as I know that will be part of my structural concern.  I have considered not making a perfect rectangle with one steep roofline, but I am still working on the math of that as to whether it would be worth trying--especially since it will include another seam in the roofline (so not likely).  It's also one thing to use a roof rake on a flat roof, it's quite another to use it on what may be (at least at first) on corrugated material.

I have actually considered that if we likely cannot finance the walipini this year, what I may do is build the roof structure as it should be for the solar angle, and just let the snows come, and observe.  I think it would be best to do this before digging the hole in the ground, for obvious reasons.  

FWIW, I have started looking into any assistance that may be available locally both for structural concerns (engineer), as well as possibly the snow/water management (fellow NE walipini owners that might do a consultation.)

Hans Quistorff wrote:Remember that glass roofs loose heat. I have observed that higher latitudes [I am at 47.25] you don.t need a glass roof. it over heats in the summer and cools too fast in the winter. My greenhouse is 16 feet deep and the su reaches all the way to the back in the winter and I only use the front third in the summer for tomatoes and basil.  So my recommendation is to dig in at the level of your driveway so that it is easy to bring planters in and out and have an insulated roof with vertical glass which is easy to drape to insulate on winter nights.  I have my zone one garden in 25 gallon barrels that I put on the north side of my greenhouse overwinter and bring them out after freezing stops. This is good for ornamental and herbs which you would like to have at the front entrance.

One thing I need to start taking photos of is how the second story bathroom jut out roofline will affect the shade that falls during the earlier parts of the day, since that's to the east.  I am trying to plan what to store in that area since I know it will lose quite a few hours of sun from the east.

I have seen a few roof designs where there is something other than glass for a few feet at an angle that would likely be more of an extension of our current roof in that area, then angles down to the ideal solar collection.  I have read on a few sites about how some have winter insulation for those not glass roof bits, as you have done.  It's something I need to spend more time learning about from others' experiences.

I honestly have not even begun to try to map out what I might grow where yet, as I have been more concerned with structure and not wanting to cause our foundation to buckle.  It is definitely something I should put more thought into, especially if we do the roof in a similar fashion to what you describe.

I have started looking into rear wall water tanks as of this month.  Are your barrels plastic or metal?  

Thank you for taking the time to explain some details about your set up.  Much appreciated.  

I am hoping to get my first rough draft of the front and side plans done within the next few weeks so I can more accurately refer to sizes and angles.  Spring is finally arriving, and we still have a lot to do towards making the rest of the grounds more than long neglected property save what little we did last year to remedy.

Lily Hope wrote:I am hoping to get my first rough draft of the front and side plans done within the next few weeks so I can more accurately refer to sizes and angles.  

That will be very helpful for us to get a better idea of what's in your head.  I was imagining that the roof would start below the windows of the first floor and drop down nearly to the ground.  But you mention it nearly matching the existing roof so that would be a much taller wallipini that I was imagining.  Luckily your imagination is much more in tune with your house than mine is

Mike Jay wrote:That will be very helpful for us to get a better idea of what's in your head.  I was imagining that the roof would start below the windows of the first floor and drop down nearly to the ground.  But you mention it nearly matching the existing roof so that would be a much taller wallipini that I was imagining.  Luckily your imagination is much more in tune with your house than mine is

Aye, I knew it's something that needs to at least be roughed soonish for a lot of the conversation to have a baseline.

Because of the snow and general moisture concerns, I'd always imagined continuing the roofline that way.  I know it could make for a very tall inside, but this is why a scale draft will get my brain closer to accepting or denying what's been floating around in there so far.  

23rd April Progress Report on the research side of planning.

I finally remembered to bookmark the relevant local code I need to follow.  

I called the Building Department today and inquired about what info I might be missing, and was told the person I should speak to is out on inspections.  They took my name and number and he will get back to me.

I also found an online walk through on our town's site of the permit process here.   Unfortunately, it seems to only be written about whole house construction, but at least this part helped give me an idea of how many interruptions there might be for interim inspections during the build:

Permit in hand, the construction process may begin. The Inspection Sequence is as follows.

Footings- Once poured and stripped, call for inspection BEFORE backfill.

Foundation Wall- Once poured, stripped, moisture proofed, with drainage pipe in place, stone  covered to code and silt cloth installed,  as well as tail off.  Call for inspection BEFORE backfill.

Rough  Frame- Once  fully  framed,  roof  and  windows  in  place, and  fully  weather  tight, and plumbing and electrical rough sign offs are in place, you are ready to call for rough frame inspection. If a fireplace has been installed, inspection for exterior combustion air, and clearance to flammables will also be completed.

Insulation  Inspection- After  all  insulation  and  vapor  barrier, as  well as ventilation  has been installed, call for insulation inspection.

I did find a table with data related to "Lot, area, frontage, yard, and height requirements".  I saw a footnote that there must be a five foot minimum to the side property line, but that's where the edge of the house currently is, so that's not an issue.  I was worried that there may have been a change to minimum width since the house was built and would have to adjust accordingly.  Overall, we should be fine in those requirements, but it's good info to know for certain up front.

I was happy to find a lot of the permit related forms online because they give me clear direction in information I will need to provide.  I also think they will help keep me on top of planning this way because I'll have to consider the various aspects as things develop.  

One really important thing I found out from looking at the various forms is I may have to also deal with the Board of Health because of the water containment system.  I just called them, and when I told her what we wanted to do, at first she said, "Well this will be a first for us."  She also said she needs to do some research and get back to me, asking me to spell the name of what we would be building (I told her she could wiki it for the basics).  I did think to ask her about cisterns, and she said she did not think we are allowed to build one.  That was a bit of a surprise because I know of older cisterns that exist from our house search (one home had them on the property plans the town's engineering department showed me), but at least I'll know for certain when she gets back to me.

I did see on the Homeowner permit application a mention of a Licensed Construction Supervisor. Further down on the form, though, it seems the owner can claim to be their own Agent, but it seems that's more for contact needs.  When I talk to the Building Department, I'll ask about them.  

I did confirm the frost depth requirement for this area for the walipini foundation (4' below grade minimum).  One thing I'm not sure about (but will ask) is if the grade in this case should be considered the outside grade, or either the open cold sink depth (lowest, but much smaller percentage of overall floor space), or the working floor area of the walipini.  (My terminology may be incorrect in trying to differentiate between cold sink and the higher used floor space.)

I've focused on earth removal and addition specific code at this point.  I've been collecting data and making a list of what I find that's relevant on what requirements need to be met to move this project forward.  I am also trying to get a sense of time frame from initial permit application to breaking ground.

The reason for my focus on those two subjects is because although there is some mention of greenhouse structures, they exclude any differences of both the fact that our project will be attached to our home (they only speak of free standing greenhouses), as well as the fact that it will require earth moving as part of the build (they don't even cover foundations in the greenhouse related code).  I can deduce from related code regarding excavation and additions what will be required, but I want to be sure that my understanding and therefore application of that information is correct before moving further in the planning process.

My short term goal is to finish my initial rough drafts of what we hope to do.  Turns out I do not still have any sort of paper of a large enough size for drafting, not even legal sized paper or a roll of kraft paper.  The storage tube only had old drafts and drawings in it.  So I have to look into if there's a nearby place I can buy more, or if I have to order some online.  I will start a grid paper rough for the time being after I discovered my lack of supplies because I don't know how long it might be before I have drafting paper again.  I am a bit itchy to see at least the elevation and floor plans to scale rather than the rough sketches I've been making.

I also need to mark out the exact depth we'll be taking down the grade on the west and south sides of the house for my own reminder how that will affect the elevations.  The regrading work will be done in advance of the walipini build, but I won't finish that before May.  I should have the measurements for that done today when I go outside shortly to do some yard clean up.

Lily Hope wrote:I did confirm the frost depth requirement for this area for the walipini foundation (4' below grade minimum).  One thing I'm not sure about (but will ask) is if the grade in this case should be considered the outside grade, or either the open cold sink depth (lowest, but much smaller percentage of overall floor space), or the working floor area of the walipini.  (My terminology may be incorrect in trying to differentiate between cold sink and the higher used floor space.)

I'm 99.74% sure this is always from the outside grade.  Otherwise basements would need footings 4' below them which never happens.  If you ask them, I wouldn't confuse them with mention of "cold sinks".  Just ask if it's from the exterior or interior grade...

Mike Jay wrote:

Lily Hope wrote:I did confirm the frost depth requirement for this area for the walipini foundation (4' below grade minimum).  One thing I'm not sure about (but will ask) is if the grade in this case should be considered the outside grade, or either the open cold sink depth (lowest, but much smaller percentage of overall floor space), or the working floor area of the walipini.  (My terminology may be incorrect in trying to differentiate between cold sink and the higher used floor space.)

I'm 99.74% sure this is always from the outside grade.  Otherwise basements would need footings 4' below them which never happens.  If you ask them, I wouldn't confuse them with mention of "cold sinks".  Just ask if it's from the exterior or interior grade...

Good to know.  I also will try to keep my query simple as you suggested.  Thank you.

I got my call back from the Building Inspector yesterday.  Nice fellow.  Definitely low key, and a fruitful conversation.  

Here's a sum up after we established that what he'd been told was accurate (and after explaining what a walipini was, which I think he's still a bit confused about as well):

- once I confirmed it's a single family home, he said we do not need the supervisor (LCS).  

- he seemed--I don't know the best word, but assured comes to mine--when I brought up finding the 5' minimum side property line related table footnote online.  (I think he was still on the fence just slightly about how much I really did know what I was doing or not at that point, and I think the shift might have been because that's not mentioned directly on the "homeowners" one pager like the LCS is, and so showed I had looked at more than just that.)  I only mention this because his direct but purposeful Q&A tone seemed to relax just enough to be noticed, and it stuck with me even now.  Maybe because my aunt was an inspector, and she would tell stories about folks that had no idea what they were getting into, and always seemed happier when she'd talk about the ones that did.  Maybe I'm just a loon and he finally had a chance to grab a seat, who knows?

- I can draft the plan/elevation myself, we do not need a structural engineer to consult or do drawings.

- once I mentioned I'd already spoken to the Board of Health about using a rainwater system for it and was waiting to hear back from them, we didn't speak further on anything regarding water use except later, when I finally had my list in front of me and asked about the cistern.

- once he knew the approximate size, that seemed to stop a possible line of questioning (I think due to what I mentioned before that if it was over a certain size, it would get deemed commercial).

- we won't have to go through the steps in the process for insulation/house wrap inspections (other than the frost protection of the foundation); don't have to worry about smoke detectors, plumbing beyond what the Health Department may care about, or electrical.

- the 4' minimum for foundation is measured from the exterior grade (so you were spot on, Mike)

- we can build a cistern, but he specifically asked if a rainbarrel wouldn't be enough to go to all the trouble of a cistern (especially since to him it's such a small structure).  We talked about cisterns more than anything else, both above and below ground.  I told him it was something we hadn't decided on for certain, and that I had to do some math on the water capture overall before I would know if we were definitely pursuing it or not.  Safety seemed a big concern for him with the cistern, although when I mentioned it may be housed within the walipini, he seemed intrigued in a good way.  I also think the scale in his mind for a cistern is much bigger than what I had in mind, given his asking if the rain barrel would be enough.

Overall, I felt he thought this would be a pretty straight forward addition, and didn't seem overly concerned about anything that came up other than the cistern.  I do think that both for him and the Health Department, our project is a bit of a good sort of curiosity.  So hopefully as long as I do my end of things well, I think they'll do their best to help it move along.

I have not had/made time to start on the grid paper work out yet.  Hubby had covered the drafting table with a bunch of his miniatures he was sorting out, which he will be cleaning up today.  I'd already tried to be clear that nothing except drawing stuff is ever supposed to be there--but he's the type to spread messes everywhere (one of his quirks, as I have mine), so in the future I'll be keeping the drafting table tilted when not in use to prevent that from happening again.  (We have a craft room, which is where our drafting table is.)  

Tomorrow will be busy for both of us, and I have a lot to do this weekend.  I should have something with dimensions to show next week though.

Updates??  and hello from a few towns over.

I have begun researching this style of greenhouse and came upon the thread. I am very interested in reading more. How did it go (assuming it was built)?