I have a 12 X 16 Cross Country and it's every bit as well made and sturdy as advertised, but did have one flaw you could easily avoid. As BC builds every GH to order, ask them to frame for a standard height door, and delete their door from the order. Then, buy a well insulated storm door from any home center. Any standard 32" wide door will fit.

However, to do so, you would need raise the foundation and set the GH on some sort of kneewall, but that's easy enough and would give you not only room for a standard door, but extra interior height for better air circulation, and BC doesn't charge extra for custom door drops.

It's not that the slightly shorter door supplied with the GH is too short to walk through, it's the need for a better, heavier door, especially if you plan to heat it in winter and standard sized storm doors are relatively cheap.

We didn't realize the door wouldn't be standard height until it was too late to change the frame for it, so replaced the door that came with it with a vinyl wrapped, wood core one. It was less than $100.00 at Home Depot and all we had to do to make it fit, was to unscrew and remove the top and bottom U shaped aluminum caps, cut 2 inches off of each end (to keep the hinges centered) and screw the caps back on.

Otherwise, I can't say enough good things about the GH and most especially, the customer service from BC.

Before you make your final decison on size, a suggestion:

Lay out your desired floor plan on a piece of graph paper, to make sure you can have what you want for your benchs, potting area, sink, heater, etc. and consider how you want to configure aisles and the widths you would feel most comfortable with. Then, buy the GH size to suit.

For heating, if you raise the foundation at least a foot, you could do as we did, and run aluminum angle across the ceiling, using the side purlins as mounting connections, and install outdoor ceiling fans.

Then, you also could have a pair of them, mounted under the roof vents, as I do, pulling hot air up and out through the vents in warm weather, and turning in opposite directions in winter, to maintain continual air circulation from end to end, floor to ceiling, and get a lot more bang for the buck from your heater.

BTW: Once we had the foundation in, it took my husband and our two adult sons less than 4 hours to have the entire frame up and ready for the polycarb. Every piece fit perfectly, just as BC said it would.

Did I mention factory direct, toll free customer service to die for?

Thanks so much for your reply - particularly the tip about the door. I had no idea it wasn't a standard height. We'd already planned to raise the foundation 18" so replacing it shouldn't be a problem.

I like the suggestion of the 2 ceiling fans. We have an attic fan not in use, but it would be a headache to move & it really moves a lot of air.

We were trying to decided between the cape cod & cottage roofs - do you have one of those? It sounds like you went with all polycarb rather than polycarb/glass combo. While I'd love the look of glass sides, we're afraid of heating costs.

We're in zone 6b-7 where the average low temp is arount 25 in the winter. Our main plan right now is to overwinter about 15 ferns that are about 3' wide & various other smaller potted plants. We also will want to start seedings & slips early in the spring. We'll most likely not use the GH in the very hot summer months. I know we need a minimum width of 10', but the 12' greenhouse is not much higher & everyone says to buy a bit larger than you think you need. It should allow us more than enoungh room for our plants, the sink & some sort of heater. Have you found your 12x 16 to be very costly to heat?

I am already impressed with BC Greenhouse. Kyle has been so helpful with me by phone. As soon as I can decided on the dimensions, I'll be placing the order. Hopefully my husband, son & I will be able to put it together.

I'm so excited - I can hardly wait. If you think of any other tips, please let me know

I have bought last year a 12 x 20 Cross Country (Curved-Eave)with a polycarbonate 6 mm twin wall.The structure is very ridgid and designed to accommodate accessories. All the instruction are well documanted and easy to follow. I have some suggestion if you ordered. Ask to have extra bolts and nuts(the head of the bolt is designed to fit in the track) for your accessories like,shelves,electric cable,pump. Also 2 sections of 10 feet of alumunium frame is very helpfull to fix your accessories between the poly bar

Here is a link that might be useful: greenhouse

Thanks so much for the post. I love your greenhouse. We are in a very wooded location similar to yours except we are not so level. Currently we're building a retaining wall to extend the available area to put our greenhouse. Your curved eave looks very nice & I like the color. We were considering the cape cod roofing primarily because it would match our house & outbuildings which will all be closeby. That may not be the most pratical thing to do. I was very interested in your coiled heating system, but unfortuantly couldn't read your website. Will try & translate it later. Thanks for the tips regarding the bolts, nuts & framing. We've not yet ordered - still in the planning stage & site preparation stage. There is so much to consider - it's hard to make a final decision. Our maximum length will have to be 16'. Although we have almost 2 acres, most is not usable due to flooding & elevation issues. If you have any further suggstions, please let me know.

My Cross Country is also a curved eave. I admit that I chose it for asthetic reasons, as my GH is a part of my garden and I wanted pretty as well as practical, and got it. One of these days I'll blow some more of "their" inheritance on the lovely Victorian cresting, as a final touch.

But my GH was planned far more to house tropical fish tanks than plants and has more space in it devoted to that use than for flats and will likely end up with the only flowers in it being in hanging baskets.

I should have mentioned the bolts, which are custom made for BC. Yes, when you order your GH, ask them to send you an extra bag of the bolts, to use to mount whatever you want to hang on the walls. You can get 1/4" SS nuts at any home center.

Additional hints? Well, I would start by suggesting that you do some excavating and run a drain line to and under your foundation, then insulate under and around it. It will make all the difference in heating and once you have the trench for the drain, you can lay in UG water, electrical and if you have it, a natural gas line.

The ceiling fans:

We went through a lot of planning, rejecting and head thumping to finally come up with what proved an easy solution for mounting them, and why I really raised my foundation and dropped the door. It was to get the heavy side purlins up to at least 8 foot above what was to be the finished floor, to use as anchors for "ceiling rafters".

We ran 1/2 inch aluminum angle from each purlin on 2 ft. centers and connected them all together with more angle, front to back. That created an exposed frame ceiling grid, (the "rafters") and using short pieces of the same angle, we created "H" brackets under each set of roof vents and mounted 52" outdoor ceiling fans to them.

There are days when the ceiling fans are all that's needed to keep the GH cool and in winter, they push the warm air down. If I had to choose one or the other, I'd take them over intake vents and an exhaust fan.

That ceiling grid also serves to support lights and electrical conduit, and will eventually have misting lines connected to it. It's also keeping the fans perfectly steady at their highest speed: not a whit of wobble.

What else? Oh, yes. You can use painted steel shelf brackets to hold a lot of heavy shelving on the polybars of a BC GH. They are as weight bearing as the studs in your house walls. Just be careful to keep the steel from direct contact with the aluminum, because painted steel can become chipped and expose the pot steel, which reacts to the aluminum. Stainless steel does not have that problem and why BC uses it exclusively. Just lay in a bag of SS washers; place one between the brackets and the polybars and avoid the issue altogether.

We lost an entire growing season laying in what ended up being an insulated foundation, with a channel drain running across the width of the GH, which feeds into a sump pit below the sink, that in turn, feeds into a long, below frost line grey water drain, and finished it all off with a glazed quarry tile floor, but in the end, it was well worth the effort.

I might compare a year round use GH in cold country with a horse. No feet- no horse. With the GH, no insulated, properly drained foundation- no year round use GH.

Besides, with a BC Cross Country, you are in the Caddy level of home GH's, so might as well give it the foundation it deserves.

Hi
I can (try) translating for you :-).

I have opted for the electric radiant heating (water). Her mi assumptions and requirements
1) Here the electricity is 'environmental' and the price is equal than other combustible.

2) I have a pump to circulate the water/glycol throw a 3500 watts heaters and 450 feet of pipes under the cement slab. Under the slap I have 3 inches of insulation = to R-21. I maintain the temperature at 50 f. and the entire greenhouse is very well temperate. I have only 2 small fans to circulate the air.

3) The surface on the floor is 100 % available for the thermal mass provide by container with water. My tables are put directly on the water container. The thermal mass is very important here in zone 4 because we have several nights under -4 F.

4)And for the aesthetic I prefer do not see propane tank in the garden because our greenhouse is integrated with other ornaments(gazebo, fountain.....)

Michel

Krayers:

I'm sorry. I failed to answer one of your specific questions- regarding the cost of heating my Cross Country GH.

We used very few additional BTU's to keep the GH at about 60 deg. all last winter, and it was a fairly cold one, but it will rise somewhat this year, as the GH will be housing my tanks and I will set the heater thermostat at 74.

Or perhaps not. We didn't have the entire interior lined in heavy bubble wrap last winter and I expect it to make a difference in insulating qualities.

However, the low cost of heating was due to a number of factors, including the insulated foundation, coupled with a solar wrap blanket and a very energy efficient, dual combustion, nat. gas heater that burns only fresh air, heated in the double flue as it comes in, so it cuts the cost there, and also allows the GH to be sealed up like a tomb for winter.

The Trane dealer/contractor who had replaced our home H/AC system the previous year recommended it, citing a quick payback in energy savings and so far, he has been proven right. One more very cold winter, and the additonal amount for the upgraded heater will have paid the difference just in gas bills and as he doesn't sell or install the heater he recommended, I took his counsel to be unprejudiced.

But do take into consideration my location. I'm in northern Illinois, about 20 miles SW of Lake Michigan, which is a mixed blessing. On one hand, we get a lot of insulating snow and on the other, we are exposed to bitter Canadian fronts that can bring Arctic air down and drop our temps below zero and keep them there for days on end, so we must insulate and heat accordingly. Being in zone 7, I expect your winters are not as bitter.

The real challenge for year round use GH owners in the midwestern US, is to address the extremes between blistering hot summers and bitter cold winters, so we try different approaches, each to hopefully, suit our intended uses of our individual GH's.

Meaning: what is necessary for my use may not be for yours, but I will still stand by my previously stated opinion about foundations, which I have expressed here many times: get your foundation right before you even unpack the GH from the shipping boxes, because once you put it up, the last thing you ever want to need to do, is to retrofit the foundation.

Virtually no amount of insulation or drainage under any GH that is to be used in winter in any area above about Latitude 40 North, is excessive.

Thank you both for all your insights. We spent all yesterday evening in 98 degree heat working on site preparation. (We're in the middle of a drought heatwave with 100 to 105 temps for 2 weeks & no rain). We're really trying to take things slow & think through everything as well as grade our site for proper drainage & runoff before we even order the greenhouse.

We'll have a bit of an advantage here I think on heating since our average winter lows are around 25F degrees & we're at this point primarily overwintering and we won't have to keep temps but in the 45F range. I have many huge old ferns handed down for 3 generations that I don't want to loose - but they like cool temps.

I'm still holding out right now for my cape cod roof - purely for aesthetic reasons, but am concerned still about heating costs. I understand high roofs with good air circulation can be a bit better at regulating temperatures & accoriding to Kyle at BC Greenhouses may not make as large a difference in heating as you might think. Fans will be an important factor to push the warm air pocket down. We also are planning to use several large containers of water for thermal mass heating. We're still undecided about the type of heating system to use. We have access to both electric & natural gas here with electric being somewhat cheaper to use in our home.

We may have to phase in upgrades over a period of time due to cost concerns. We are trying to follow your advice & lay a very good foundation now. My husband has built several structures & is familiar with footings, laying bock, etc. We will be pouring a footing & doing a 16" raised wall that we'll later face with stone. We plan to fill the interior of the concrete block & use foam insulation. Our frost line here is not very low at all & ground temp is probably not nearly as bad as further north.

I'm keeping notes of all your suggestions & will do as you have both done regarding the extra aluminum for the ceiling area to affix the extra elements, the extra bolts, etc. I've been looking for sturdier doors but am having problems finding them in the brown color we will be using, so we may have the go with the BC door.

Again thank you both very much. It's so helpful to hear from others who's alrealdy successfully been through this & who can share tips to help us with a successful completion to our project. We hope to be able to have the site & foundation readly by the end of September if fall harvest & the weather will cooperate.

Kim

Kim,

Kile can send a container of spray paint that the same color than your greenhouse. Is very helpfull for a touch up or paint your accessories..........or a door

Thanks also to Birdwidow for the hints

Michel

Kim: As Michel said; you will receive a can of touch up paint with your GH. If you ask him, I'm sure Kyle will give you more. Or, just ask them to sell you an extra can of it.

If you want unlimited access to greater amounts of matching paint, just paint a small scrap of flat metal with the touch up paint that will come with your GH for a color sample. With the computer color matching available at any large paint store these days, you can buy a quart of satin finish oil paint, perfectly color matched.

Thank you both - I've added the touch up paint to my order list. We hope to set the remainder of the retaining wall today & begin the dirtwork to level the site & adjust the
slope for proper drainage. We've had to take out 2 small trees & having to compact the area where we dug out the roots. The themperature is finally to be below 100, so work should be much easier.

Unfortunately harvest here starts Monday so we'll be out of pocket for a while. Maybe soon I can get the house ordered so we'll have it ready as soon as we can get caught up!! You've both been great to give me so much valuable information. I'm very excited & hope we'll do as good a job as you have with yours. I still have much to learn. If I ever get time, I'll post photos of the site & our progress.

Thanks again,

Kim

Just wondering if anyone has updates to their Cross Country Greenhouse info / Pictures.??? I am planning on purchasing one from BC but am undecided on the Cross Country or Cape Cod design. Living in southern NH the weather can vary quite quickly. With heavy snow, high winds, NEGATIVE 26 degree days (at times) and then 60 degrees two days after, I want to have the bases covered. I do not want to be out in the middle of the night to clear the roof of snow.

I thought that the curved eaves of the Cross Country would aid in snow sliding off but then the higher pitch of the Cape Cod would also (and give more head room). SO I am quite indecided. Any suggestions would be greatly appreciated... Thanks! Tom

Tom,

The curved eave does indeed induce snow to slide right off, long before it can accumulate enough to do the least damage. It may also creates an airfoil that moves air over, rather than against it, like the curved surface of an aircraft wing, so the design may actually offer more resistance to strong winds.

That aspect is one that didn't concern me, as my GH is sited where it's well protected from wind. I chose the curved eave more for asthetics, but I made a dreadful error in not insisting on a higher kneewall.

If you want to avoid my own most serious error, plan on a knee wall at least 30 inches high. Then have BC cut the door drop to fit, and you will have the high ceiling that makes such a difference in any GH, along with superior lower insulation.

If you think about it, you don't need light under your benches that in any case is a great place to store potting soil, pots, flats and other sundries that would otherwise take up growing space. You could even buy some all vinyl base cabinets sold for garages, with doors and drawers and keep thngs really tidy.

As long as you have it set onto a well secured, dead plumb foundation, a balloon framed knee wall will support a GH as well as it does a house or garage and give you the opportunity to have a really well insulated lower section.

Then, just face it on the exterior with whatever appeals to you, or matches your home and use a waterproof facing over blueboard on it inside; with lots of insulation between the studs. If you have the ambition and skill to tape, you could also just paint the blueboard with enamel.

Something else I would do differently is the top board on the base. We used 6" wide cedar that extends out over the base wall a bit, with a bullnosed edge and a drip channel dadoed into the underside.

If solid vinyl trimboard had been as available then as it is now, I would have spent the extra and used it instead, and had the outer edge planed to a slight drop like a window sill and never had to do anything with it again save hit it with a pressure washer.

Also, with a high kneewall, you can mount intake vents through them and avoid cutting into the polycarb. That design also allows the vents to be mounted low to the ground, where they should be, with absolutely no air leaks. You just need to frame for them, then seal around them as you would a window, with foam.

Thank you Birdwidow...! Lots of very good ideas that I will keep in mind. I had wondered about air flow and the curved eaves. One question though is the polycarb cirved or is it bent around the curved rafters..?

I wonder if it would be worth using concrete block for the kneewall and covering that with rigid foam insulation...?

Tom,

The polycarb sides run in a single piece from base to top. The polycarb is flexible enough to be bent into the curved shape and the uninterpted run is likely another factor in causing the snow to slide down so easily.

Concrete block will work, if that's your preference. You will end up with a pretty thick wall after you add the insulation, but if that's what you want; go for it.

But even with foam insulation, you might not have as much R-Value as you would by balloon framing it with 2 X 6's or even 2 X 8's. It might be worth checking into.

Concrete blocks would make creating a space for intake vents a bit trickier, as they would require metal headers, unless you might be able to use longer flat blocks or, considering where you are; perhaps some pieces of cut granite but you could still end up with totally sealed vent frames, which makes a real difference in winter and admittedly, a pretty much forever foundation.

BTW: Friends of ours had a new house constructed a few years back and had the contractor use 2 X 10's for the exterior framing. It's a pretty good sized place, and because of the extra thick walls, they had to add additional trim inside the windows, but the cost difference for both the lumber and insulation was less than $8,000.00 and when fuel prices went through the ceiling, they had the last laugh and, some really nice window sills for plants, kids and cats to sit on.

It's amazing what rewards can be gleaned in a very short time by spending more up-front on insulation. After which, it's all gravy.

Tom, We just finished our 2nd winter with our cape cod greenhouse, and we love it. It is not only very well made, very functional, but also looks great in our yard. It has withstood some horrible winds (we lost several trees), ice storms and torrential rain with no problems whatsoever. We built a 10x16 on a high kneewall which has given us a huge amount of space indoors. Later, we faced the concrete kneewall with stone. The house is very tall at its peak. We used Birdwidow's suggestion of 2 ceiling fans which has given us very good air circulation. We current hang at least 10 giant ferns on the purlins & have all the lower space availble for shelving & storage. We used twinwall & have not put bubble wrap over it yet. Our first winter was very mild & didn't make a huge impact on our heating bill. This winter, however has been horrible. We were able to keep the house warm, but would have definately benefited from bubble wrap or solar pool covers. We did not put a concrete floor in the house, but put a very deep floor of pea gravel with pavers inset in the walkway.

I'm adding a link to our photobucket ablum which includes photos of the greenhouse. They are not new or updated, but will give you an idea of the finished exterior. We're still working on the interior. Right now we have cuttings rooting, seedling started and are overwintering a huge amount from last winter. We hope to soon add a warmer chamber within the greenhouse to start my caladium bulbs. They like it warmer than I'm willing to keep the air temperature, but I think it will be easy to section off a small corner & keep it warmer, or maybe try heat mats to warm the soil temp. We're still learning & modifying, but its been great fun.

Hope this helps.

Kim

Kim, Thank you for the info and the attached Pics. Beautiful greenhouse! What zone are you located in? I love the stonework that you have done outside. Did you do the block foundation or have it professionaly done? Thanks again Tom

Thanks Tom, We actually poured a solid concrete kneewall - My husband built forms. Later we applied manufactured stone and a cap stone to the exterior - we used the stone that's flat on the back & did not require mortering between stones. It wasn't that diffcult - just very time consuming. We are pretty much "do-it-yourself" folks. The foundation was much more time consuming than the greenhouse itself. Be sure you have your foundation square & level - particularly for the cape cod style since it is so tall. The kit will work great provided everything is on a good & square base. If we had it to do over again, we'd probably lay concrete blocks - it would have been easier, but we're really pleased with how it all turned out. We are barely in zone 7. It's been an unusally cold & miserable winter here this year. We really don't keep the greenhouse temps very high at night - only in the mid 40s on most night because our ferns don't mind the cool temps. They do quite well. Seedlings & cuttings probably would like it a little warmer - they've liked the warm days we had last week.

Kim

Thank you again for the info !!

Birdwidow And Krayers Would you have any more pictures of your greenhouse and foundation you could forward to me. Tprav@aol.com

We are about to decide on a greenhouse through BC and I am still torn between the Cape Cod and Pacific (curved) greenhouse.. (10X12) We atr trying to decide on the final items like the kneewall etc and ceiling fan installation. Thank you again for all od the help !!! Tom

Tom,

I haven't any photos of my GH in it's finished state and don't know that I can add much more to this discussion that I already posted, but if you want to use ceiling fans, and I can't urge you to do so more strongly as they make such a difference; then whatever roof style you choose, if you want to use our aluminum L "rafter grid" design for mounting fans, make sure you construct a kneewall high enough to get the long side purlins at least 8 ft. up from the finished floor, because the fan blades must be high enough to allow you to walk beneath them.

They also need to be high enough that if you want to mount overhead lights; to avoid the strobe effect, they must be hung beneath the blades, also high enough for head clearance.

So look over the plans for both models and consider the height of the side purlins, as the height of the roof in the Cape Cod model shouldn't be confused with the height of the side walls and the purlins run along the top of them. If you ask him, Kyle will have the BC engineering dept. email the schematics for both models to you in PDF format, so you can print them out and play with dimensions.

Once you do order your GH, ask for the instruction booklet in PDF anyway. I put the instructions that came with the GH in a ring binder, which was very handy during the construction phase and when several pages got torn, I was able to immediately replace them from the file.

I know that a number of GH owners have rigged up plates attached directly to the center roof truss to mount ceiling fans, which raises them and that could make a lower side wall still fine for fans, but we inadvertantly discovered another use for those "rafters" this winter, when it was so very cold.

We had a lot of extra bubble wrap set aside and when looking up at the grids, realized they would also serve as a platform to hold bubble, so we laid long strips of it atop the grids, which created a space rather like attic, trapping warm air under it.

But again; my GH is far more a tropical fish room than plant house and we each fit out our own GH's to suit our own desires for their uses.

However, when all is said about it, if I had the opportunity to do it again, my kneewall would be counter height above the finished floor, regardless of the roof style, height at the peak or the type of material used on the floor.

The ability to erect it atop a kneewall at whatever height you want, at no additional cost for the door drop custom made to fit perfectly, then enjoy such wonderful customer service is just another bonus of a BC, regardless of the size or style.

Tom, I'm sorry but I don't have any new pics to offer today, will try to take some if I can & post them. We are so pleased with our cape cod & are really happy with the high knee wall. It's not quite counter height, but we still have a lot of storage space below our shelving. Because we used the cape cod design ceiling height is not a problem for mounting the fans. We used 2 inexpensive small ceiling fans with the lights attached below the blades. We have plants hanging on the purlins & they don't come anywhere near the fan blades. Actually, the greenhouse is so tall, the hanging plants are above my height leaving much room below them for shelving. You would, however be heating a little more space than with the other model. I don't know if that would make a significant difference in your heating/cooling costs or not.

Good luck with your greenhouse. I think you'll be please with the quality of the BC kits & they are so helpful if you run into problems.

Kim

Thank you Kim, Yes I imagine the heating would be a bit more costly. I will keep that in mind. Thanks again.... Tom

We are ordering the Cape Cod 10 X 12 in twin wall poly carb, 2 or 3 of the 4' cedar benches, heat will be an Empire unit probably the one that does not require electricity ( we had no power for 1 week after an Ice Storm in December, some areas 2 weeks), Sidewall vent, and will build a framed insulated 2.5' kneewall... Electrical I will do. Planning on at least 1 ceiling fan and some overhead lighting.

With a 30 inch high kneewall, you will have no trouble mounting a large ceiling fan and in winter, with the blades set to push air down, will also not have your heat trapped up at the peak.

The lower you mount your heater the better and with that kneewall, you will be able to vent it through the kneewall, a much better solution than cutting through the polycarb.

But are you sure that heater won't require any electricity? Even to operate the ignition? Doesn't it have a fan, to push the warm air out?

There are two designs for the heater. I already have one used in an office area in the back of a garage. The only power needed is for the fan if you use a fan. Without electricity you will still get heat, just nothing to blow it around. The better model has electronic ignition( No pilot) and is more efficient. For the kneewall I figured 2.5' which would bring the sidewalls up to 8' and then the ridge would be more like 14 + feet...

We do have a generator which could easily power the heater if needed... so that is not cast in stone... ;)

Contratulations! I think you will be really pleased with your choice. One bit of advice. Be sure to get your foundation very square & level. With the cape cod, because it is so tall, if you get a little off, it makes it much more difficult for all the parts to fit together properly. They do a wonderful job with precision measurements & as long as you are square, everything should fit together great. You will like the extra height, & should have no problem mounting the fan. We put our 2 directly under the roof vents, & that way we can reverse them in the spring & exhauset the heat through the vents. Keep us posted on your progress.

Kim

Yes, as Kim notes, get that foundation absolutely and totally PLUMB, and every part of your BC will go together perfectly, with no need for the least adjustments.

We spent months on the foundation under mine, but the end result was worth it and when it finally came time to erect the frame, my husband and our 2 sons had my 12 X 16 Cross Country up in just under 5 hours. The only parts he pre-assembled before they came for the "put-it-up" day, were the vents.

The polycarb panels were installed, sealed and the cover stips secured over the course of the next several weeks. However, they also fit perfectly. The time it took to finish was really due to a pair of old hearts amd muscles that couldn't go very long without stopping to rest, than any difficulity in getting everything in place.

Also yes- set ceiling fans under roof vents and they will outperform intake vents and exhaust fans- silently.

I'm so glad I have my ceiling fans because the racket of the wall mounted exhaust fan gives me headaches and even on very hot days, when it does aid the total exhaust/cooling effort, I often turn it off while I'm working in the GH, just for some peace and quiet.

But your taller ceiling will also provide a GH naturally cooler in high summer and given proper insulation, it's a lot easier to keep a GH warm in the coldest winter than it is to cool it in summer, so also agree that you made a very good decision.

Thank you all for your help in the process. It is greatly appreciated. I will be sure to speak to the people building the kneewall about it being perfectly level and square..!

In speaking to Chris today at BC it sounds like shipping might be in as soon as a week once the order is signed!

We had better get the process started on this end. Thanks again... Tom

Two years ago I made heavy use of this thread and others on Gardenweb trying to decide how to build a greenhouse. I learned a lot in the process and ended up constructing a 10x14 greenhouse mounted on a 30" concrete wall. I bought it from BC Greenhouses and the whole interaction with them was wonderful. It's all twin wall polycarbonate and that has been sufficient for the worst winter we've ever had in Maryland using just their standard 4 kw 220v heater.
I got the ideas for building it up on the wall and using a full-time overhead fan from this forum and I couldn't be more pleased with the results. Anyway, I thought I should provide some payback to the forum by sharing my happy experience. I've posted pretty regularly on the experience of using the greenhouse and constructing it on my blog at MacGardens.

I'm starting to look at getting my first greenhouse and stumbled on BC Greenhouses and then this thread. Sadly my project will be smaller than the ones discussed here, but this thread is still full of excellent tips! I have bookmarked it for future reference.

Are any of you still around and able to give updates on your greenhouses 4, 7, or even 10 years later?

Thanks!

Welcome to this thread. As I wrote previously I learned a lot from people's comments. If you go to my postings at macgardens.org you can see many comments about my use of the greenhouse including the lovely South African bulbs coming into blossom right now. Mechanically the greenhouse has held up very well. I especially love the way I've been able to automate the watering and the use of the Bayliss automatic vents that open up when it gets too hot. I originally thought I was going to use screens but it turns out to be much better to be open to the outside world for pollination and developing a natural balance with insects. I have preying mantis and spider populations that seem to have kept the pests in check. I occasionally have to spray an individual plant for aphids but haven't had to do even that for more than a year. Because I had elected to build it elevated on a concrete wall, I was able to build a raised bed on both sides that I use for alpine flowers (very stony mix).

Thanks willisjw! That's a great looking greenhouse. Your website has lots of information and I will spend some time poking around there. :)