Most inexpensive way to build a small guest house?
jackofalltrades777
| Posted in Green Building Techniques on
Would a SIP, ICF or stick frame be the quickest and most inexpensive way to built a small < 1,500 square foot guest house? This would be in a Zone 4 climate. The most important factors are build-time quickness, strength and simplicity.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Peter,
Q. "The most important factors are build-time quickness, strength, and simplicity."
A. If I wanted to be cute, I'd answer:
If you want build-time quickness, go with SIPs.
If you want strength, go with ICFs.
If you want simplicity, go with stick framing.
You want all three, of course. So you'll have to decide what's most important to you. Talk to a builder and get some bids. My guess is that you'll end up with stick framing.
Martin,
Good and valid points. I looked online and they have ready to install SIP kits for around $10k for under 900 sqft homes. This included the roof and walls with all windows and door cut outs and all electrical outlets installed/cut at the factory. It's quick and relatively easy to assemble. Slab on grade for the foundation.
I'm trying to keep the budget under $30k for this tiny guest house.
Consider also a modular factory-built approach.
Another comment:
If it will often be unoccupied, you probably want low thermal mass so you can leave it semi-conditioned and quickly bring it to a comfortable temperature when needed. A slab on grade is not the best choice for that.
Peter- you can't build a 1500 square foot house (or 500 square foot house) for anywhere near $30,000. If your budget is really in that neighborhood, you need another plan. By the time you do a cheap kitchen, minimal heating and cooling, minimal lighting, cheap windows and doors, Tyvek siding, no trim inside or out, etc., you are at $100K at least.
1500 ft^2, or even 900 ft^2, doesn't meet my idea of "tiny." What are you looking to accomplish in terms of number of occupants, frequency of occupation, etc.? Would your guests need to cook, or would they eat with you? Are you planning to finish it yourself after the structure is up?
Are you doing all the work yourself?
Excavation is going to eat up a huge part of your budget. Look into piers or helical piers to save $.
Monolithic slab-on-grade with AAC walls. Look into http://crescoconcrete.com/liteblok-38. Simple, strong, durable, DIY-friendly, relatively quick due to the interlocking nature of the blocks.
Of course your budget is only feasible if you provide close to 100% of the labor and get a lot of the materials from Craigslist or other free or hugely discounted sources. It's possible; people do things like give away whole kitchens when they remodel. But this substantially reduces the speed of construction, of course. Plaster the walls yourself (not hard, just labor-intensive). Plumb it yourself with PEX. Install a DIY mini-split for heating and cooling. Install flooring when you're able; virtually-free Craigslist tile right on the slab should work fine. The roof will be expensive no matter what.
How did you come up with a budget of $20 per sq ft?
Malcolm,
Every plan starts with a dream. Peter's dream is a 1,500-square-foot house for $30,000.
Not every dream can become a reality, of course. But every plan has to have a starting point. Once Peter starts shopping (or soliciting bids), the dream is likely to change.
Manufactured/Mobile Home?
I should have clarified, my fault, but I was looking more to something like a "small" or tiny house kits they have. So it would definitely have to be below 900 sqft. It would be for 1-2 occupants. It would have to be site assembled on a slab on grade foundation.
No excavation needed besides the footings (18" deep) since there is no basement and it's slab on grade. The tiny house could be below 900 sqft with a simple layout. Online I noticed they have "SIP kits" that sell for around $10k-$15k that includes the walls and roof and can be assembled by a DIY person since they are all factory designed kits.
So is it possible to do one of those tiny house kits for under $30k, under 900 sqft, if the work is mostly DIY?
Peter,
You can buy a tiny house kit from 84 Lumber for $20,000. That will give you a house measuring a little under 200 square feet. And you'll still have $10,000 for the foundation, electrical service, and plumbing service. (OK -- I don't think you can do those three things for just $10,000.)
Of course, the furnished version of the tiny house from 84 Lumber costs $50,000. But that busts your budget.
It sounds like your best bet is to build in the time honored tradition: a little at a time, as materials and funds become available. This is basically how non-professionals build everything in the 2nd and 3rd world. You stockpile building materials and hunt for good deals wherever you can, and put in some labor whenever you have a few hours. Note that it's practically impossible to build the walls of wood this way, since the wood will be destroyed by the elements due to the slow pace of construction--especially engineered wood products like OSB. That's why I recommended AAC blocks; they're masonry, so there's no special rush to finish the building envelope ASAP, in addition to the advantages of just being better in most ways.
After you've gotten the foundation done, raise the walls as time, funds, and materials permit, block by block. Once the walls are all done, build the roof. You can probably get some nice metal panels on the cheap if you're patient and diligent.
Plastering the walls is easy and fun. Cement plaster is cheap to make and pretty forgiving compared to lime or gypsum plaster, and will adhere well to the blocks. On the outside, add sodium silicate to the plaster mix to make it more waterproof, and then apply a topcoat of sodium silicate after you're done. This will substantially waterproof the blocks but allow absorbed moisture to dry to the outside. If you add white pigment or a white additive such as hydrated lime, metakaolin, or ground granulated blast furnace slag to your cement plaster mix, you'll get a nice white wall and won't even need to paint.
You can run conduits inside the blocks to prepare for electrical work or put the conduit on the outside, exposed, which will make any future work dead-simple and nobody really minds the appearance anyway. DIY supply plumbing with PEX or PVC is not particularly challenging, and even copper can be learned without much trouble. Again, scrounge materials inexpensively, but acknowledge your limitations; if you don't have experience with plumbing or electrical work, strongly consider hiring these jobs out as funds permit.
Decent windows can often be procured practically for free when people put their old ones up for sale after replacing them. For heating and cooling, use window ACs and space heaters until you can afford a DIY-able mini-split for about $1,000.
You won't need any wooden trim with this approach, but for anything that needs trim, or for baseboards, use thin skinny tiles. Cheap, easy to do, durable, and beautiful.
Good luck! If you've never done something like this before, understand that it's an enormous amount more work than you might be imagining. But it's doable!
Martin,
There is no worse way to start a project than with an unrealistic budget. Things always end badly. 30Gs is about that I'd include as a contingency for a project that size. If you do have money left over when things are all done, you can donate it to charity, spend it on cocaine and hookers - whatever.
If Peter does want to try and build for that amount, I'd suggest not telling any sub-trades or suppliers. They will run in the other direction.
I have experimented at the low $ end of the guest house strategy.
This method does not usually conform to the local zoning law*, but maybe those laws are due for a change?
It's just an $8000 used Scamp in the backyard, attached to the utilities. Keeping the the water supply from freezing was a challenge I solved with a $35 recirculation pump.
A one minute interview with a happy resident: https://www.youtube.com/watch?v=bvH-ufaR4u4
*The laws aren't that clear. You can legally store a travel trailer in your yard, but you "can't live in it". In most cities, no one has clearly defined "living in it"
Maybe Kevin D. now has $21,965 to spend on the things listed in Malcom's above post.
The old timers built their hunting camps and lakeside camps back in the day with reused and tossed away materials. I have been on many building that had hand dug foundations, cement blocks laid up a course a weekend, hand hewn lumber or knotty pine from a local sawmill, old windows from the bungalows that were torn down to make way for the interstates, tin roofs ( sometimes made up of old signs off of buildings) pink toilets, hand made pine counters (or linoleum countertops) and cabinets, simple well points that drew cold water, even outhouses out back! Anything is possible if you have a long time frame, a sharp eye, a trailer, a few sets of hands to help out, an opportunistic streak, a handle on Craig's list, maybe a connection to a demolition firm, and certainly a remodeling guy or two in the family like I have. I get sinks, appliances, trim, baseboard heaters, if I want them. You can be choosy or not be choosy... but I sure would be looking to build something about 200-300 SF on a slab or a crawl space or even piers. Some type of efficiency layout or studio apartment set up. Source your windows, roofing and framing lumber and work up plans. Be ready to dry in fast and then take your time going along. You probably need a storage garage to stash the stuff you will be collecting too. Then you will probably have to determine if you have a compliant bureaucracy that will allow such a thing. Often that is the biggest hurdle.
Malcolm,
We're on the same page on the question of whether Peter's budget is realistic. My musings on "everyone has a dream" was an example of dry New England humor -- a little too dry, evidently.
Martin,
No it was just the right amount of dry. It's just a topic that keeps cropping up in my practice in new and novel variants. The most pernicious are the "I agree with your estimate but secretly think I can build it for half that." And: "This is my dream. Surely you realize that and will somehow make sure it comes about even though we can't afford it".
But hey - I guess that what second mortgages were invented for.
Malcolm: During our initial discussions with our architects, they estimated the total project cost. I was sure they were crazy. They weren't. They were right on the money.
Stephen,
That initial shock aside, your build seems to have gone fairly uneventfully. Lucky guy.
What initial shock? I was positive the architects were wrong:-)
The build went fine and we still love our architects. I think they knew what we wanted and got us there, of course with the assistance of a great builder.
I'm ready to do it again, but don't need (and can't afford) another house.
We have had a running joke for years. Any time we see an interesting building feature, one of us pipes up: "For our next house..."
To those flat out dismissive, I do think it's possible to build a 900 sf house for around $30,000 if the OP can do the labor himself and already has the tools needed for construction, and there are a lot of ifs. Also, think more like building a simple cottage. The foundation can be an insulated grade beam. The finish floor can be smooth troweled concrete. The siding/sheathing could be T-111 and the roof could be a simple rafter gable roof. If there is an existing well and septic that can be shared, basic plumbing could be completed for $3000. Basic electrical for $2500. Building materials for getting a dryer in exterior with shingle roof would be in the $6000 range. Insulation $1000. Drywall materials only about $700. Add it all up, and my budget has about $6000 left for cabinets, trim, interior doors, appliances, and one mini split. Challenging, sure, but I am reasonably confident that a very simple, self constructed house could be built for this price, IF there aren't expensive permits required, and if there is some infrastructure already in place at the site, such as driveway, electric service, etc.
Rick,
Doesn't this just become a game? Why pick 30,000? Why not figure out how someone could build for 10? What if all his relatives where in the trades, or owned a lumberyard?
Posters here generally agree that code minimum practices aren't something to aim for. PeterL has been vocal in his criticism of poor construction, and always advocates using European high performance windows. Where does that fit in?
Assuming that one lives somewhere without building codes, it can be quite fun to try to build a house that costs as little as possible. In the mid-70s, my friends and I were all engaged in attempts to build a house for zero dollars (or close to it).
Among the work I performed, witnessed, or participated in at that time were the following:
- Digging foundation holes with a shovel.
- Building piers with stone and mortar.
- Mixing concrete in a wheelbarrow with a hoe.
- Gathering building stones down at the creek.
- Building stone chimneys.
- Finding window sash at the dump and thinking I had won the lottery.
- Cutting down cedar trees for a log cabin.
- Cutting down spruce trees and squaring them with an adze for joists.
- Negotiating with farmers to tear down old barns and haul away the boards for free.
- Finding old sinks and bathtubs for free.
- Removing the hardwood floors from buildings scheduled for demolition.
If you are young and the work is legal, all this is fun. You won't end up with a Passivhaus, though.
Yes, I wasn't implying that this would be an admirable house. Also, Martin's post is on the money. With a strong back and time, a lot can be accomplished. I work in the building trades so my perception of what is possible is skewed. Also, many of my friends are in the construction trades, so finding a people with the requisite skills is easy for me. However, if you follow prescriptive code and learn as you go, building a simple house is truly not that difficult. And besides, what is more green---A 4,000 sf passive house or a 900 sf code min?
Also, the original question was about a guest house, which might not be conditioned all the time.
Charlie,
That's an interesting point. Our code notes that some leniency has traditionally been given for seasonally occupied buildings but that "with the greater use of 'cottages' through the winter months... and the increasing installation of modern conveniences in these buildings... the extent of possible exemptions is reduced".
It goes on to say that if you don't install any heating appliances you don't need to insulate, but if there is any heating used you have to follow all the appropriate insulation and air-sealing requirements.
Plus if you are heating it, you are usually required to install things like Ice and Water underlayment. Regular old tar paper is out. All of that runs up the price. If you are building a summer-only cottage, the costs come way down.
Resurrecting this old thread from a few months ago, what if he used one of these?
http://www.homebuiltcompany.com/#smallgable
It's only 120 sq feet but it's under $30k if you provide all your own labor. There are some larger kits on the site, too.
Hi Peter,
I do not know how your guest house project is going. I recently just built a pool house/guest house including outdoor kitchen area. It is on a 6" concrete slab with standard 2X4 construction with fiber glass insulation, minisplit heating, water heater. total area is 18X28, including indoor 18X22 and 18X6 for outdoor kitchen. The height is 17 feet so it can accomandate a second floor/loft for sleeping. I also installed a toilet room and a shower room seperately since it is mostly to service the pool. A cooking wood stove is installed so it could be a kitchennett. I am the GC for this project, but most work is done bu many subcontractors. the total cost including interior everything is about $85,000.
I hope this information helps for anyone want to build a small structure in the backyard.
Helen
The cost includes the pool house, the outdoor kitchen, not the deck. I also the GC for this 1500 SQFT IPE deck as well. which saved me 40% of the cost.