Solar Shed Summary: My Off Grid Office(sevarg.net)
sevarg.net
Solar Shed Summary: My Off Grid Office
https://www.sevarg.net/2016/07/31/solar-shed-summary-my-off-grid-office/
67 comments
Well, YMMV. I looked into permit-free structures in one California county. 1. 120 ft^2 max, outside dimensions. 2. No electricity > 30VDC. 3. No plumbing. 4. No wood-burning appliances.
You could still squeeze an office or studio into something like that. But it is easy to trip over a code-requirement that needs a permit.
You could still squeeze an office or studio into something like that. But it is easy to trip over a code-requirement that needs a permit.
I've been trying to find codes on the 100-150sqft foot shed no permit rules for various counties but can't always find it. Tried looking for the state level code (MI) to no avail. Have any tips for finding that info.? I'm also wondering what penalties I could face if I just went ahead and did it anyways (no intention of selling property), but that likely varies county by county.
Search for planning and zoning on small structures or sheds, cabins by County. I searched on Emmet with "Emmet County Building code small structure" and second link is a pdf. If they aren't indexed well, you have to look through their complete building code info and search on small or accessory structures.
Man, that’s restrictive. I can build up to 100m2 here, external area, up to three stories, no permits or inspections.
Can vouch that roofing is hard damn work - but perfectly possible to do solo - our roof is tiny, only 70m2, but still took me about ten days from ceiling boards to tiles on. It would have been a lot easier with a helper.
Can vouch that roofing is hard damn work - but perfectly possible to do solo - our roof is tiny, only 70m2, but still took me about ten days from ceiling boards to tiles on. It would have been a lot easier with a helper.
In which country did you settle? 100m2 is already quite a building surface. Is it a maximum per land plot or per building btw?
Portugal, in a very depopulated rural area. Per building. There are some restrictions around use (can’t be a permanent residence without a permit). So far we’ve only put up a single 45m2 cabin, but have plans for a few bits and bobs, spread over ~10ha. Building out our own power and water grids, vermiculture sewage treatment where needed. Their attitude is “it’s your land, you do what you want”.
Time to start learning Portuguese then.. Here in France anything above 5m2 needs to be declared (plus taxed), and anything above 20m2 needs a permit.
This is good info. Another thing to be mindful of is property easements - they're different everywhere and they can change over time.
There's been some conversation about this at the previous link, back when it was over at syonyk.blogspot.com (I moved off that because Google ruined their new Blogger interface).
Five years later... still the best place I've ever worked from. Nothing to say, really. Power is reliable, I have more of it than I really need with how much solar I've got, the generator works fine in the winter, my speakers rock, and I don't have a commute. I cannot recommend such a thing highly enough.
//EDIT: Oh, I suppose I also have Starlink out here, but Dishy is so power hungry it lives on the house and I run connections out it over the property area network if my primary rural WISP connection (on the office) is acting up.
Five years later... still the best place I've ever worked from. Nothing to say, really. Power is reliable, I have more of it than I really need with how much solar I've got, the generator works fine in the winter, my speakers rock, and I don't have a commute. I cannot recommend such a thing highly enough.
//EDIT: Oh, I suppose I also have Starlink out here, but Dishy is so power hungry it lives on the house and I run connections out it over the property area network if my primary rural WISP connection (on the office) is acting up.
Do you have any measured stats on your Dishy's power consumption? I've read it's 90-100W nominal, which seems reasonable if you switch it off at night when not in use. Like other commenters, I've been also been thinking about off-grid home requirements.
https://www.sevarg.net/2021/06/20/so-starlink/
It's around 85W continuous on the white hardware, I understand some of the newer generations are a bit more power efficient. Power use while transmitting goes up higher.
I just run it on the grid. :/ Yes, it's 2kWh/day.
It's around 85W continuous on the white hardware, I understand some of the newer generations are a bit more power efficient. Power use while transmitting goes up higher.
I just run it on the grid. :/ Yes, it's 2kWh/day.
Seems reasonable until you realise an LTE router draws 1-2W. I live off grid, as do a number of friends. They all rushed out and got starlink as they were making do with bad LTE installs - and now can’t use it as it’s way outside of their energy budget. I won’t consider moving to it until we have hydropower and wind. It’s just too much power for a damn internet connection.
FYI TFA is just a blank dark scrollable page without js here on FF w/noscript.
Interesting. Indeed it is, I just tried with JS disabled. That certainly wasn't the intent, I'll have to figure out what it's doing. However, it shouldn't be setting any cookies...
Web dev is no longer my strong suit... never really was, but I used to know a lot more about it than I do now.
Web dev is no longer my strong suit... never really was, but I used to know a lot more about it than I do now.
It's the fade-in animation on page load. Everything is blank until Javascript adds the "is-in" class to <body>
Thanks, I'll see if I can resolve that. Sorry, it's been quite some years since I've messed with CSS much (just bought this template), so I'll try to resolve this. I didn't realize it was quite so JS dependent. :/
I'm curious how your batteries are holding up? I know effectively nothing about lead acid battery lifespans, but I saw a question asked on your blog concerning the heat the batteries would be subjected too. Did you ever hook up a AC system for the batteries?
They're fine, about halfway through the expected service life. I haven't bothered heating or cooling them, they're just boring old lead acid, floating away out back.
im not op but im an offgrid farmer i use lead carbon batteries they have held up well. on a 5k inverter i run a 70 inch tv, stand alone freezer and a fridge/freezer. my home lab has been reduced to a few pis a unfi usg plus a couple of access points. i have an lte 4g ptp connection. i use gas for hot water and cooking (kinda cheating) woodfire in winter and i currently cook in summer but am working on a daytime solution with some extra panels and a second inverter -> reverse cycle. these batteries are 5 years old still going strong. only thing i dont run is stuff with an element like electric kettle. other than that no huge difference in quality of life.
I didn't expect Starlink equipment to be very power hungry. That's unfortunate. Really damages my rural off-grid small home fantasy.
2kWHr/day is about 500 watts of solar panels (just for starlink, similar math for the rest of the stuff). So that's about $750 plus brackets, wires and stuff. You'll need a battery bank and you will trade off the size of the battery bank against the size of the solar array to survive partly cloudy days, but there will always a cloudy period longer than your batteries will provide, so get a small generator running on whatever fuel is convenient (you want to charge using at least 1/4 the capacity of your generator to keep the efficiency up, so small generator unless you have vast batteries). Then you don't need such a big battery bank or solar array.
In the cost of a small home, the solar/battery/generator is minor. $1500 panels, $1000 inverter charger, $1000 lead acid batteries (5 years, then lithium will make sense), $2000 generator, $2000 more because I underestimate… $7500 all in.
Fantasy is still a go!
In the cost of a small home, the solar/battery/generator is minor. $1500 panels, $1000 inverter charger, $1000 lead acid batteries (5 years, then lithium will make sense), $2000 generator, $2000 more because I underestimate… $7500 all in.
Fantasy is still a go!
Why not? It’s a phased array, and the bandwidth is high, so you need a decent amount of RF power. The amplifiers aren’t very efficient at the kind of frequencies it operates at so that makes it worse!
For reference, a company I worked at produced a Ka-band (27.5-31GHz) block upconverter that produced 25W (this was used for geostationary mostly, usually with a 1m dish), and it could draw something like 200 W or more when saturated.
For reference, a company I worked at produced a Ka-band (27.5-31GHz) block upconverter that produced 25W (this was used for geostationary mostly, usually with a 1m dish), and it could draw something like 200 W or more when saturated.
Well, it's talking to satellites 400 kms away.
It's about as power hungry as your laptop. Less so than a desktop. It's totally reasonable if you're installing a solar system to add a little more capacity to handle that much load. You can also turn it off when you aren't using it(or have your access point turn it on only when a wireless device connects to it, or something like that).
Same here, thought Starlink would be low power. Still, 100W is acceptable I suppose
This is an amazing read, and something I might do some day. A thing I've learned recently living in Japan's tiny places, is that good insulation helps you keeping electricity costs down but has the disadvantage of building CO2 faster.
So I would strongly consider getting a CO2 monitor for the shed. Considering size and the strong insulation you added, I doubt you can be more than a couple of hours before getting into "warning" CO2 levels (1000-2000ppm), and a full work day inside there very likely gets you into dangerous levels (2000+ ppm) which is associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present[1]
[1] Health Effect tab https://www.dhs.wisconsin.gov/chemical/carbondioxide.htm
So I would strongly consider getting a CO2 monitor for the shed. Considering size and the strong insulation you added, I doubt you can be more than a couple of hours before getting into "warning" CO2 levels (1000-2000ppm), and a full work day inside there very likely gets you into dangerous levels (2000+ ppm) which is associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present[1]
[1] Health Effect tab https://www.dhs.wisconsin.gov/chemical/carbondioxide.htm
Yeah, I have a CO2 meter, and you're right. I tend to leave the window a bit open with a fan circulating, and especially if I've got a burner running for heat in the winter. During wildfire season, I just accept that a bit of CO2 is less-bad than the PM2.5 levels (100+ ug/m^3 on a bad day), though I've considered building an algae based CO2 absorber for in here.
The other problem is if one has farted, it takes all day to clear unless you've got a window open.
The other problem is if one has farted, it takes all day to clear unless you've got a window open.
If you wanted to increase the air quality a good bit without losing out on too much efficiency you could look in to adding an ERV or HRV. Unfortunately since they are a fairly new and still niche item they are pretty pricey.
The Lunos eGO could work well for your shed: https://foursevenfive.com/lunos-ego/
The Lunos eGO could work well for your shed: https://foursevenfive.com/lunos-ego/
You can always put in a energy/heat recovery ventilator. They use the outgoing stale air to warm/cool the incoming fresh air, so it’s more efficient than leaving a window open. Downside is they need a small amount (20-60w) of power for fans.
These should be ubiquitous. Fresh air is so...refreshing.
Heat recovery ventilation unit is also helpful. It ventilates air while keeping temperature and humidity. Lossnay (ロスナイ) is most popular one in Japan, and it's sold from 20k JPY.
It's really the air tightness that causes CO2 buildup, rather than insulation. "Insulation" tends to mean materials which reduce thermal conduction - e.g. rockwool, PU foam etc. You can have a very well insulated but also well ventilated space which doesn't have CO2 buildup (obviously at the cost of some thermal performance). Likewise you can have a very airtight but poorly insulated space which does suffer from CO2 buildup (the most extreme example being an inflated plastic bag). The shed may be air tight, but the presence of insulation isn't causing that.
As others have said, the solution is a heat recovery ventilation system. These use counterflow heat exchangers to move almost all the heat energy from the outgoing air to the incoming air - generally they have an efficiency of about 80%.
As others have said, the solution is a heat recovery ventilation system. These use counterflow heat exchangers to move almost all the heat energy from the outgoing air to the incoming air - generally they have an efficiency of about 80%.
Neat project! I just finished a daylight basement remodel, the corner of which is my new office, and I learned a lot of the same lessons. GRK screws are super nice. Rock wool is way nicer to work with than fiberglass. Expanding spray foam can go into lots of nooks and crannies to make a space feel less drafty. Chalk lines marking the studs are a great idea.
One lesson that I'll add is that a dry wall lift (https://www.amazon.com/Drywall-Lifter-Rolling-Caster-Constru...) changed my project from "nigh-impossible" to "totally doable". I hung almost a 1000 sqft of drywall on the ceiling solo with that thing. Even if I never use it again, it was worth the money.
Now to go read all of OP's solar design posts to prep for my next project.
One lesson that I'll add is that a dry wall lift (https://www.amazon.com/Drywall-Lifter-Rolling-Caster-Constru...) changed my project from "nigh-impossible" to "totally doable". I hung almost a 1000 sqft of drywall on the ceiling solo with that thing. Even if I never use it again, it was worth the money.
Now to go read all of OP's solar design posts to prep for my next project.
Why not just rent the drywall lift? If your work stretches across a week it's not cheaper, but the goal would be to rent the lift, hang all the drywall, return it to the lumber-yard/home improvement store/hardware store by the end of the day.
1000 sq ft of drywall is probably several evenings of work for a DIY'er, and not something you want to force into one long day.
I will sometimes buy tools like this (new or for craigslist) and resell on craiglist, and then I think of it as "renting from craigslist" but without a deadline to return it.
I will sometimes buy tools like this (new or for craigslist) and resell on craiglist, and then I think of it as "renting from craigslist" but without a deadline to return it.
Yeah...
When I was doing house solar (big ground mount 15.9kW system), I really beat the hell out of myself trying to finish with a rental jackhammer in a day. I was drilling the holes and the auger was bouncing off the hardpan, so I rented a jackhammer... and it was an electric beast, not a light pneumatic version. Anyway, I got it done in a day of pounding, but I was not in good shape the next few days.
Having low stress of getting it done is nice.
Also, depending on the area you live and the community you're part of, that sort of thing may just go into the general rotation of "Oh, yeah, I've got one of those." I'm borrowing someone's portable cement mixer right now for deck footings, a friend up north has my auger, I've got his subsoiler... in rural areas, useful tools tend to just wander around, and as long as people have a vague sense of where they might be, it's not a big deal.
When I was doing house solar (big ground mount 15.9kW system), I really beat the hell out of myself trying to finish with a rental jackhammer in a day. I was drilling the holes and the auger was bouncing off the hardpan, so I rented a jackhammer... and it was an electric beast, not a light pneumatic version. Anyway, I got it done in a day of pounding, but I was not in good shape the next few days.
Having low stress of getting it done is nice.
Also, depending on the area you live and the community you're part of, that sort of thing may just go into the general rotation of "Oh, yeah, I've got one of those." I'm borrowing someone's portable cement mixer right now for deck footings, a friend up north has my auger, I've got his subsoiler... in rural areas, useful tools tend to just wander around, and as long as people have a vague sense of where they might be, it's not a big deal.
Good point. I’ve got friends who use the same approach, but I gotta say, I think they do less reselling of things than they think. But that’s not really a problem (unless you run out of room) of course.
> Even if I never use it again
I reckon it would make a good solar panel mount. Maybe with a bit of weather-proofing.
I reckon it would make a good solar panel mount. Maybe with a bit of weather-proofing.
I've spent far more while arranging for space at home, and the resulting workspace is not as great.
I wish there was such a Shed-as-a-Service in a bikable distance from my home.
Seriously, I believe there is some demand for local, tiny offices for remote workers.
I wish there was such a Shed-as-a-Service in a bikable distance from my home.
Seriously, I believe there is some demand for local, tiny offices for remote workers.
They have this sort of stuff in cities that have enough of a population to sustain these sorts of industries. There is this in my area but its not exactly cheap compared to the price of a late at a cafe:
https://secondhome.io/location/hollywood/
https://secondhome.io/location/hollywood/
I pitched this to some coworkers. Remote Work Cabins I believe was what I called them. I think the idea was that they were in the woods and you got a little cabin with a fiber optic internet connection and a communal common area where lunch was served (dutch oven type cooking). Trails would run around the property for runners or hikers to enjoy a stroll. That was the pitch anyway- I think getting woods close to any sort of urban or suburban centers is harder.
> Seriously, I believe there is some demand for local, tiny offices for remote workers.
I'll second this. I need a real office most days due to having a ton of voice and video calls, but private office space at most co-working spaces is both overkill and around $1000/month, which is kind of silly.
I'll second this. I need a real office most days due to having a ton of voice and video calls, but private office space at most co-working spaces is both overkill and around $1000/month, which is kind of silly.
The challenge with tiny structures is usually building codes. Also, in a city setting, the cost of the dirt is likely going to mean you wouldn’t like the daily rate very much even if someone built it.
That said, I’m developing some work/live spaces that is a new zoning concept for my local municipality. They’ve essentially addressed some of the limitations regarding multiple structures, how far apart the need to be, parking, sanitation, etc to make it a bit more feasible. This was really progressive for the town to come up with and something I’ve been looking to do for a long time.
That said, I’m developing some work/live spaces that is a new zoning concept for my local municipality. They’ve essentially addressed some of the limitations regarding multiple structures, how far apart the need to be, parking, sanitation, etc to make it a bit more feasible. This was really progressive for the town to come up with and something I’ve been looking to do for a long time.
Coworking spaces are a thing, and - being tired from WFH - I am currently enjoying working in those. As much as I wish I could build something like this, this is a good enough option. The price is a bit steep in the large city where I live: 500 CAD for dedicated desk and about 1000 CAD for 1 person office. On the flip side you have all the niceties of the modern office, including espresso machines and sometimes beer and carbonated water on tap! Curious to see if all the extra office space from people not wanting to return to the office depresses the prices.
A trend I've noticed in my area (north Austin) is taking old houses and converting them into small co-working spaces. I've seen a few of them but I feel like for the cost, you could quickly build a shed.
For a similar setup, see https://usesthis.com/interviews/joey.hess/ and https://joeyh.name/offgrid/ .
In the bay area, also check out "The Shed Shop". I'm a happy customer myself. You can also make it a studio shed with sheetrock, flooring, electrical. They have a pricing sheet on their website and lots of sample sheds in their showrooms.
https://www.shedshop.com/models-prices/studio/
https://www.shedshop.com/models-prices/studio/
I built a 36x24' Tuffshed with a 650sqft loft above it in the grambrel roof. Took me nearly 2 years to get all of the utility work and drywall and stuff finished.
Great build and very similar to my off grid office. Tuff sheds are unbeatable for the price.
I went with a 16' x 12' (max size without needing a permit). Spray foamed the interior. Have not needed AC, but planning on putting in a 9k BTU mini split for heating/cooling.
I have a 3.3kWh 12v battery for accessories (lighting, water pump, fridge, cameras, 5G/wifi) and a 5.6kWh 48v for the rest.
I bought 5kw of used panels but have not mounted them (right now only 1.25kw hooked up laying on the ground)
Future plans are to try solar hot water storage - either insulated vacuum tubes, or dumping excess solar -> heating element.
I went with a 16' x 12' (max size without needing a permit). Spray foamed the interior. Have not needed AC, but planning on putting in a 9k BTU mini split for heating/cooling.
I have a 3.3kWh 12v battery for accessories (lighting, water pump, fridge, cameras, 5G/wifi) and a 5.6kWh 48v for the rest.
I bought 5kw of used panels but have not mounted them (right now only 1.25kw hooked up laying on the ground)
Future plans are to try solar hot water storage - either insulated vacuum tubes, or dumping excess solar -> heating element.
I thought about some hot water storage, but I just don't have the space for the tanks, and it seems more trouble than it's worth. I have heaters, but mostly bundle up in the winter and focus on keeping myself warm. An incandescent bulb over the keyboard is great for heating hands too!
TFA mentions difficulty trenching in rocky soil as an obstacle for running power to the shed. I'd like to point out that running power overhead is also an option.
It is, but that comes with other problems that not having overhead stuff simplifies, like not being able to run the tractor around, and having the office then officially grid tied, which means I need inspections and permits and such.
It's totally fine off grid, and I like it that way, plus it offers me a rather robust backup power system.
It's totally fine off grid, and I like it that way, plus it offers me a rather robust backup power system.
This appears to be from 5 years ago. I would love to see a follow-up!
Way off topic, but the brand of shed he bought, Tuff-Shed, had a series of TV ads that will be forever stuck in my head. The voice-over was a call and response that played on the fact that the brand name sounded like tough shit. Need somewhere to store your lawn mower? Tuff shed! Tired of all your stuff getting rained on? Tuff shed!
Way off topic, but the brand of shed he bought, Tuff-Shed, had a series of TV ads that will be forever stuck in my head. The voice-over was a call and response that played on the fact that the brand name sounded like tough shit. Need somewhere to store your lawn mower? Tuff shed! Tired of all your stuff getting rained on? Tuff shed!
There's a bit of a follow up here: https://www.sevarg.net/2020/05/23/on-working-from-home-and-j...
But... really, there's nothing much to say. It just does what I ask of it, which is to be an amazing workspace.
But... really, there's nothing much to say. It just does what I ask of it, which is to be an amazing workspace.
IIRC K-Mart ran a TV ad that played on "shipped" sounding kinda like "shit", promoting their ability to ship stuff you bought. "I shipped my pants!" "I shipped the bed!"
Great share, and incidentally I view this as a model of good documentation. It was interesting, long but not too long, engaging, very well illustrated, and also appealed to people who wanted to drill down further. The article hits all the high points, and at the end of each one there's a blank line and a brief paragraph linking to another page with more detail.
Thanks! I hate how everything has gone to video, so I protest that as much as I can with my blog, and stick to text/photos unless a video really does add something. Glad to hear you like the format too!
Nice attention to detail. Couple things, for those interested in this topic for structures great and small:
1. Air sealing is typically more important than insulation, so definitely good that you foamed those windows. Sometimes it's even good to put a more elastic seal in those areas that's more robust over time. 2. By means of the rigid foam, you addressed thermal bridging, which is an important way to increase the overall thermal resistance of the assembly. 3. Depending on where it's produced, XPS foam, though readily available, is not the most environmentally friendly. In the US, it's typically produced with blowing agents that have relatively high global warming potential (GWP). 4. If you're curious about high performance building, Green Building Advisor (https://www.greenbuildingadvisor.com) is a great place to visit!
1. Air sealing is typically more important than insulation, so definitely good that you foamed those windows. Sometimes it's even good to put a more elastic seal in those areas that's more robust over time. 2. By means of the rigid foam, you addressed thermal bridging, which is an important way to increase the overall thermal resistance of the assembly. 3. Depending on where it's produced, XPS foam, though readily available, is not the most environmentally friendly. In the US, it's typically produced with blowing agents that have relatively high global warming potential (GWP). 4. If you're curious about high performance building, Green Building Advisor (https://www.greenbuildingadvisor.com) is a great place to visit!
Interesting read. I also live off-grid and repurposed an old shed to be a workspace of sorts but my solar power is only for lighting and the laptop (the inverter is just 250W) which is sad since we get lots of sunlight here. Worst part is the internet, I use shitty 3G, often can't stream even videos lol. Planning to get Starlink when (if ever) it comes to rural Africa. Inspiring post, thanks.
Where do people go living offgrid like this? I'm in Los Angeles and will probably never afford a house here due to the high cost, maybe a townhouse some day. Anyone has suggestion for good states or cities that will be good for building your own houses? I've never been out of California really and most of my friends are in CA as well.
Pretty much anywhere in the Midwest is builder and home-buyer friendly, with the caveat that the further you are from a city, the easier and cheaper it is. Anecdotal stories I've heard put IA, ND, SD, WI, MI, MN, IN, NE and KS at about the same level for suburban to rural housing (though this depends on the size and popularity of the closest city). It is typically cheaper (not including maintenance costs) to buy an old house than to build your own. You can buy an old 2000 sqft house for under $200k within commuting distance of the Twin Cities but building a similar house on an empty lot will likely cost more than twice that and have a 10-20 min longer commute.
This is very cool, I have solar on my house, but I started tinkering with a panel for off grid use.
https://youtu.be/E9Ea2n1vryo
Solar Bilge Pump - Moving Thousands Gallons of Water Off Grid! Kid Homeschool Solarpunk Engineering
https://youtu.be/E9Ea2n1vryo
Solar Bilge Pump - Moving Thousands Gallons of Water Off Grid! Kid Homeschool Solarpunk Engineering
Great shed! I have question. What about noise inside from AC and inverter? Could you measure it?
I'm sorry, I no longer have an easy way to do that. The inverter is dead silent unless it's loaded up, at which point I've got enough other running loads that I don't really hear the inverter. Air conditioner makes plenty of airflow noise.
I think it's around 70dB on a typical day, quiet mornings can be down in the 50dB range? I measured it a while ago, but I no longer have the smartphones I used to do that around.
I think it's around 70dB on a typical day, quiet mornings can be down in the 50dB range? I measured it a while ago, but I no longer have the smartphones I used to do that around.
Shouldn't you also insulate the floor? If you did that, how did you retrofit insulation there?
I didn't have the floor insulated my first winter, and, yes, it was quite chilly in there (keeping my feet warm was very hard).
It wasn't done by the time the original post went up, but the following year, I added more insulation, including some insulation under the floor. A local company used an open cell foam insulation designed to have a low curing pressure (so it wouldn't pop the floor up). I also improved the insulation on the eyebrow windows.
https://www.sevarg.net/2017/12/24/solar-shed-part-17-more-in...
It wasn't done by the time the original post went up, but the following year, I added more insulation, including some insulation under the floor. A local company used an open cell foam insulation designed to have a low curing pressure (so it wouldn't pop the floor up). I also improved the insulation on the eyebrow windows.
https://www.sevarg.net/2017/12/24/solar-shed-part-17-more-in...
1) Most areas allow 120-150 sqft as max size with no permit. thats usually interior dimensions so if you want it all you have to buy longer lumber and cut down to maximize interior. 2) Counties usually do not allow any interior water or electrical wiring w/o inspection. So exterior solar and battery box and extension cord run in to power stuff. 3) If you buy something pre-built, make sure they built on 16” on center or some other standard otherwise you will be hand cutting every piece of insulation. 4) Metal roofing is pretty cheap at Home Depot, but right now you have to order a minimum number of sheets (I wanted 14’ sheets, but at qty of 10, twice what I needed, so bought shorter lengths) 5) Many items I had to special order two years are stocked at HW stores. For example, Techshield OSB which has a foil face is cheap and dramatically decreases interior heat transfer in walls and attic 6) Watch YT videos on deck building and framing. There are many good examples. A flat deck is half the battle. Much of this can be done alone with practice but you really should have help for rafters, roofing and ceiling plywood. It’s easy to get injured trying to handle 1/2-3/4” plywood 12 feet up.