UPDATE: On my RV building plansWell, you spoke..... and I listened.Thank you to all those that provided feedback to me on my RV building plans. Your ideas and suggestions have been very helpful. Some of the things pointed out to me were; - My trailer was too high. (This was a rendering error and I corrected it) The actual trailer should come in at no more than 11' now.- I didn't have enough storage. Now I added a storage cabinet over the desk and an access door to storage below the trailer in the back.- Someone even pointed out that my tongue was not in the right spot and I corrected that.If you haven't seen my plans to build an RV or you want to see the rendering revisions I made please go to: MY RV PLANS If you have any more suggestions, ideas or feedback I would greatly appreciate it.Fondly, -Darla

Thanks for the update. Another suggestion - take photographs or have the builder do it as the build progresses. Knowing exactly where the framing is located and where the electric and plumbing run will make future changes and additions much easier.

You have perviously posted that you plan on using a RV builder to help you complete this project. From the 2+ years that I have been on this forum....one thing pretty much universally stands out, most if not all RV's on the market are cheap thrown together crapola unless it's a mega expensive 5th wheel or custom bus. It seems like you have a pretty good plan so possibly you should expand your builders to outside the RV trade?

I still think you are causing yourself some major expense with the vertical elevations of your plans. By putting the floor height up a foot over the as built deck, you'll have to add onto the wall height, have poorer egress/ingress, and add more drag when towing. I've mentioned that you can maintain the existing as-built elevations by insulating the floor from the exterior. The concept you have will require that the whole exterior wall structure needs to be cut off and modified if you intend to have a continuous exterior panel. In previous RV use, the entry door and it's catch must have given you some grief. That will be less grief than the amount of water infiltration you'll suffer with an in-swing door. As was also noted in your previous thread, here, trying to get around laws dealing with grey water discharge is a recipe for headaches. I wouldn't try it.

OP's Blog wrote: I’m going to try to keep a fairly clean gray water tank (basically soapy water from sink and shower) so that it does not require a sewer system to be discharged. I do know it's illegal to dump even just a grey water tank outdoors in some states, but I don't think there would be any harm to the environment if I had to dump that soapy water discreetly in a pinch.westend wrote: As was also noted in your previous thread, here, trying to get around laws dealing with grey water discharge is a recipe for headaches. I wouldn't try it.You can try to gloss over this part of your plan, but I'd take the advice given by westend. If it was OK to do this, it would never be necessary to do it discreetly.Now when are you going to actually going to start building?

2012Coleman wrote:OP's Blog wrote: I’m going to try to keep a fairly clean gray water tank (basically soapy water from sink and shower) so that it does not require a sewer system to be discharged. I do know it's illegal to dump even just a grey water tank outdoors in some states, but I don't think there would be any harm to the environment if I had to dump that soapy water discreetly in a pinch.westend wrote: As was also noted in your previous thread, here, trying to get around laws dealing with grey water discharge is a recipe for headaches. I wouldn't try it.You can try to gloss over this part of your plan, but I'd take the advice given by westend. If it was OK to do this, it would never be necessary to do it discreetly.Now when are you going to actually going to start building?Just a side note on shower water being clean, I don't think so. If you are human, Fecal Coliform bacteria will be present. You need to rethink the gray water or constantly carry a portable gray water tank to avoid issues with the authorities and other campers.

Update: On my RV Building Plans.... | Good Sam Community

myrvplans1
Explorer
May 20, 2014
Huntindog wrote:
A couple of thoughts. Are you stuck on 15'?
It occurred to me that since most building materials are 4x8 standardized, that making the TT box 16' would likely yield some savings in labor, and not add any to the cost of materials. Most of the materials cut off over 15' will just be thrown away, and you would be paying someone to do it!. An extra foot would not be noticed at all when towing, but could make a substantial impact on the interior, at basically zero cost.
It may not work out to exactly 1 foot of extra room, and you would have to have the cargo trailer selected in order to plan it that close.
You would hate to be a inch short in the materials.
But some detailed construction planning couild pay some dividends.

In another post, we talked about how to handle the rear door. IIRCC, you said that the trailer builder could just wall it off.
I think that keeping the doors, if they are the swing open type could have some advantages.
First off it would keep the stealth mode consistent with your desire to not look like a camper.

Next is it would make the construction a LOT easier. If the rear is walled off, then everything will need to be brought in thru the small entry door. This will slow things down considerably and drive up the labor cost.
You could make a sort of false wall back there for when the doors were open, or have a screen wall like some toy haulers have. Might be nice sometimes to have some extra ventilation
Another thought: If you got a ramp rear door, you could use it as a patio. I have even seen pics of a toy hauler with this setup with the ramp hanging out over a lake, so that they could fish off of their own "dock" It looked pretty cool

Finally with the raised floor plan, if the rear doors were still there, you could access the area under the floor just by opening the doors. The possibilities here are endless. You could install some of those long slide out drawers like some camper shell kits have. One could even store one of those fold up canoes in there. Obviously, some of this space will be occupied by tanks etc. so thinking this out in advance would be necessary.

THANK YOU HUNTINDOG! I've been waiting all day to respond to your post. I really appreciate your feedback. Good stuff.

1) I think you're absolutely right about having to go to 16'. They seem to make the base cargo trailers in even lengths. The extra 12" could help out in a few areas. (When they say something like an 16x8 cargo trailer are they referring to a 16' box length or 16' from the rear bumper to the tongue hitch?)

2) I like your idea about keeping the ramp door as a patio or to appear more "stealth-like." But, I ask the question... with an awning a/c and vent on roof, 2 windows and propane tanks haven't I overplayed my stealth hand? There are a bunch of guys online that built stealth cargo conversions with no windows (People want my head on a pike cause I only have 2 and they think I should have more), so I'm not sure I'm gonna fly under the radar even omitting the RV swirl graphics.

3) While initially I was describing it as a "raised floor plan", it's not exactly that. There was an artist rendering error in my first set of drawings which showed it as a skyscraper on wheels.... it's since been corrected) I told the artist to "draw the vehicle so the floor plan laid out over the wheel wells creating sort of a basement".... he took that to mean add a basement area in addition to the area above the wheel wells. The trailer now comes in at around 11'-11.5' in height.... about 4" higher than my previous 31' TT.

Thank you again! Regards, -Darla
myrvplans1
Explorer
May 20, 2014
Gdetrailer wrote:
Thought I would dig up a few "resources" which may help to explain some of the pitfalls of Darla's design.. Hopefully you will find some of this info enlightening..

Although the plans are “dated looking” they will give you some insight to typical RV construction and I would recommend the following website for a real good look at actual home built RV plans..

Nothing says you have to follow the plans to the "T" but you will gain some inside knowledge on how a typical RV is constructed.

There are even photos posted by folks who bought and built the plans.

GLEN-L RV PLANS

“GLEN-L is the name of proven quality in the do-it-yourself field, and we gained this reputation simply by offering the best R-V plans available. There may be other so-called "bargain" plans available, however, we doubt that you will find ALL of what we provide in our various Plans & Pattern packages regardless of the price. Remember, the value of a good set of plans will be repaid many times over by preventing mistakes and wasted time, not to mention shoddy construction and possible safety hazards to your family.
Only GLEN-L offers all of these features...

Plans: With our Plans you receive a unique "package" that is complete and intended just for the R-V you have selected. All our plans are intended for amateurs who may have little or no experience reading blueprints. They are based on decades of experience providing plans to the amateur builder and cover all phases of the construction. The quality of our plans is so highly respected that you have no doubt seen them featured many times in national magazine articles.
Instructions: Our voluminous GLEN-L Construction Manuals are furnished with all Campers and Travel Trailers. These manuals are the finest available and include numerous photos of the construction taken during the prototype development. Our Husky & Outback include step-by-step instructions as a part of the PLANS. In short, we leave nothing to chance.

Material Listings & Layouts: All campers, travel trailers, and pick-up covers have material listings of wood and fastenings for the basic structure so you can determine costs before construction begins. Camper plans come with material layouts so you can cut the plywood with a minimum of waste. Travel Trailers have listings which tell you what plywood panels to use and where.
Patterns: Only GLEN-L provides a real full size patterns system to simplify and speed construction of the sidewalls of your camper, travel trailer, or pick-up cover. No additional layouts are required. You assemble directly over the pattern sheets we provide thereby assuring the size, shape and symmetry of your recreational vehicle.
With this system you receive a full-length pattern for campers giving all contours and positions of sidewall members. With travel trailers you receive full height patterns giving the contours and positions of sidewall members at front and rear ends to perfectly "key-in" the simple GLEN-L sidewall construction. You also get full size patterns for the wheel well cutouts and for the cambered roof beams of the trailer. We know that the value of our pattern system will exceed many times the price of the package.”

The sidewall typically used in RVs actually works a lot like a trussed beam when the inside paneling is attached to the 1x2s in the side walls and therefore the side wall panel BECOMES PART of the strength of the RV trailer.. This allows the RV manufacturer to use lighter steel beams under the trailer box since the walls strengthen the RV.

The following is discussions on truss beams

HERE

HERE

“Why trusses?
A truss provides depth with less material than a
beam
It can use small pieces
Light open appearance (if seen)
Many shapes possible”

Another very good resource is from a fellow who built a 5th wheel trailer from scratch

Original thread

CHAD'S 5TH WHEEL THREAD #1

Second thread

HERE

A very good read on “composite sandwiches” although the article focuses on the marine applications the principle is the same when used for any lightweight yet strong panels.

I HIGHLY RECOMMEND READING THE ENTIRE ARTICLE IN THE FOLLOWING LINK.

FOAM CORE COMPOSITE

Here is a snip of the link.. but in the link they give some diagrams which should help understanding of the principles.

“Sandwich Principle
The sandwich concept is based on two main ideas: increasing the stiffness in bending of a beam or panel and doing so without adding excessive weight.”

Something else that I have noticed missing in your design is a secondary “emergency egress”, in other words you have only ONE way out of the trailer in case of fire.

If the door gets jammed or the fire is in front of the door you have no other way to get out.. This is critical that you have a secondary egress, typically in RVs you have one door and ONE EMERGENCY EXIT WINDOW. In the case of my TT I have two doors and STILL have a emergency egress window..

Not to harp further on the door thing, it IS easier to make a hasty exit if the door swings outward.. Having a exit door which swings inward will cost you precious seconds of time which may be the difference getting out alive or not..

Inward doors also wastes your usable floor space, a three foot wide door will require a min of a 3’ x 3’ area inside the door which NOTHING can be there.. Not even a shoe. And if you want the inward door to be able to swing more than 90 degrees open then it will take an additional 3 ft of wall space (you need 3’ for door opening plus 3’ for the door to swing against the wall eating up 6' of wall space)..

Okay GDE.... You're a strange bunny hon. I can't tell if you're trying to help me or trying to waterboard me? Your posts are kind of extensive and I am really trying to understand your point. Are you suggesting that a cargo trailer conversion is inferior to a typical fiberglass production trailer? I got it that you don't like the floor plan or that you think I am going to spend too much to do the conversion. But, get back to the cargo trailer for just a sec... are you suggesting that a high quality vehicle can not be produced from a cargo trailer? Are you telling me a company like this (see link) that builds $500,000 conversions can't figure out a way to put a shower enclosure, bed and 48" kitchen counter in a 15' cargo trailer??? Are you telling me that a company like this that builds high tech mobile command centers for Homeland Security hasn't figured out a way to properly insulate or is going to do "shoddy construction?" (and there's dozen others like this company)

http://www.beckercustomtrailers.com/trailers/custom

Addressing you point about reselling in the future; First, all trailers, motor homes, Class B, C or whatever depreciate the minute you drive off the dealers lot. So in building this trailer I am not giving any thought to it's value years later...only to the value it is to me now. For example I'd rather have no oven and more space now than put one in so I can get an extra $400 selling 6 years from now. (And incidentally my internet research reveals many consumers are also opting to omit an oven/stove from their new RV purchases so it's not quite the radical idea that's implied.)

Now I can tell you that even with my limited knowledge of RV building construction I did employ what I think are smart design decisions which might add to resale value if I ever did decide to sell it;

1) There are no slideouts, no steps, no odd shaped areas... it's a simple open rectangle design with 4 straight walls. Meaning, once a solid structure is built and the key components are installed (tanks, vents, a/c, etc.) the rest is just cabinetry and so it can be gutted easily an remodeled. So if in the year 2021 it was mandated by law that all trailers have ovens I could have one installed in an afternoon. If someone wanted to add another bunk that could be done. If someone wanted to add a flush toilet, a door to the shower, a door to the bathroom or change the vinyl flooring it could all be done easily.

2) Okay, here's the biggie. Ready? No matter what I do this cargo trailer (even if I put the entry door on the roof) it will always be worth at least something as a cargo trailer or hauler of something. (Whereas an an old gutted fiberglass RV isn't really worth anything except to someone that wants to do a complete rebuild such as you did (how big is that demographic?)

You noted that my floor plan did not have another point of egress. Please look again. It has a small rear emergency hatch type door (not unlike the door you would see on the back of a school bus) that only opens outward. I didn't want to put it in, but I just didn't want to have that regret. Also, both windows are egress windows that push out.

While I was waiting at the airport today I was looking at trailer rebuild you posted. You are quite a talented carpenter. I'm not sure I like things like an air conditioner on the floor, but it looks as if you put some time into it. I understand that you did this as a hobby project, but what do you think your 2-3 years of labor time were worth? Thank you for all your comments. Regards, -Darla
myrvplans1
Explorer
May 20, 2014
OhhWell wrote:
http://www.coolrunninghs.com/ls090hxv.html

What is that? Does it need venting?
Gdetrailer
Explorer III
May 19, 2014
Thought I would dig up a few "resources" which may help to explain some of the pitfalls of Darla's design.. Hopefully you will find some of this info enlightening..

Although the plans are “dated looking” they will give you some insight to typical RV construction and I would recommend the following website for a real good look at actual home built RV plans..

Nothing says you have to follow the plans to the "T" but you will gain some inside knowledge on how a typical RV is constructed.

There are even photos posted by folks who bought and built the plans.

GLEN-L RV PLANS

“GLEN-L is the name of proven quality in the do-it-yourself field, and we gained this reputation simply by offering the best R-V plans available. There may be other so-called "bargain" plans available, however, we doubt that you will find ALL of what we provide in our various Plans & Pattern packages regardless of the price. Remember, the value of a good set of plans will be repaid many times over by preventing mistakes and wasted time, not to mention shoddy construction and possible safety hazards to your family.
Only GLEN-L offers all of these features...

Plans: With our Plans you receive a unique "package" that is complete and intended just for the R-V you have selected. All our plans are intended for amateurs who may have little or no experience reading blueprints. They are based on decades of experience providing plans to the amateur builder and cover all phases of the construction. The quality of our plans is so highly respected that you have no doubt seen them featured many times in national magazine articles.
Instructions: Our voluminous GLEN-L Construction Manuals are furnished with all Campers and Travel Trailers. These manuals are the finest available and include numerous photos of the construction taken during the prototype development. Our Husky & Outback include step-by-step instructions as a part of the PLANS. In short, we leave nothing to chance.

Material Listings & Layouts: All campers, travel trailers, and pick-up covers have material listings of wood and fastenings for the basic structure so you can determine costs before construction begins. Camper plans come with material layouts so you can cut the plywood with a minimum of waste. Travel Trailers have listings which tell you what plywood panels to use and where.
Patterns: Only GLEN-L provides a real full size patterns system to simplify and speed construction of the sidewalls of your camper, travel trailer, or pick-up cover. No additional layouts are required. You assemble directly over the pattern sheets we provide thereby assuring the size, shape and symmetry of your recreational vehicle.
With this system you receive a full-length pattern for campers giving all contours and positions of sidewall members. With travel trailers you receive full height patterns giving the contours and positions of sidewall members at front and rear ends to perfectly "key-in" the simple GLEN-L sidewall construction. You also get full size patterns for the wheel well cutouts and for the cambered roof beams of the trailer. We know that the value of our pattern system will exceed many times the price of the package.”

The sidewall typically used in RVs actually works a lot like a trussed beam when the inside paneling is attached to the 1x2s in the side walls and therefore the side wall panel BECOMES PART of the strength of the RV trailer.. This allows the RV manufacturer to use lighter steel beams under the trailer box since the walls strengthen the RV.

The following is discussions on truss beams

HERE

HERE

“Why trusses?
A truss provides depth with less material than a
beam
It can use small pieces
Light open appearance (if seen)
Many shapes possible”

Another very good resource is from a fellow who built a 5th wheel trailer from scratch

Original thread

CHAD'S 5TH WHEEL THREAD #1

Second thread

HERE

A very good read on “composite sandwiches” although the article focuses on the marine applications the principle is the same when used for any lightweight yet strong panels.

I HIGHLY RECOMMEND READING THE ENTIRE ARTICLE IN THE FOLLOWING LINK.

FOAM CORE COMPOSITE

Here is a snip of the link.. but in the link they give some diagrams which should help understanding of the principles.

“Sandwich Principle
The sandwich concept is based on two main ideas: increasing the stiffness in bending of a beam or panel and doing so without adding excessive weight.”

Something else that I have noticed missing in your design is a secondary “emergency egress”, in other words you have only ONE way out of the trailer in case of fire.

If the door gets jammed or the fire is in front of the door you have no other way to get out.. This is critical that you have a secondary egress, typically in RVs you have one door and ONE EMERGENCY EXIT WINDOW. In the case of my TT I have two doors and STILL have a emergency egress window..

Not to harp further on the door thing, it IS easier to make a hasty exit if the door swings outward.. Having a exit door which swings inward will cost you precious seconds of time which may be the difference getting out alive or not..

Inward doors also wastes your usable floor space, a three foot wide door will require a min of a 3’ x 3’ area inside the door which NOTHING can be there.. Not even a shoe. And if you want the inward door to be able to swing more than 90 degrees open then it will take an additional 3 ft of wall space (you need 3’ for door opening plus 3’ for the door to swing against the wall eating up 6' of wall space)..
Gdetrailer
Explorer III
May 19, 2014
Tonyandkaren writes “Nice job on the trailer rebuild Gdetrailer!”

Thank You!

It was a lot of work but in the end well worth it since it is customized to OUR needs and tastes, something like ours will most likely not be something others will want..

“Your experiences with factory built trailers shows why some people such as Darla chose to build using a cargo trailer. No doubt her trailer will weigh more and be expensive but she's getting a very solid, practically leak proof base to finish out exactly as she wants it “

While my rebuild does show typical RV "weaknesses" keep in mind I was operating on a 25 year RV which had been EXTREMELY NEGLECTED. It spent 15+ yrs sitting in a RV park and the owners failed to do needed routine maintenance like checking and replacing caulking.

While a lot of folks will think cargo trailers are “better” and do not leak that is further from the truth.

Case in point.. HERE
Under service they state they fix..

“Roof and exterior leak repairs” as one of the "services" they do..

Even Semi trailers leak (the construction is typically the same as cargo trailers)

This is one example of a roofing material developed for leaking Semi trailer roofs..

SEMI ROOF COATINGS

Here is a post of someone with a cargo trailer roof leak..

LEAKY CARGO TRAILER LINK

Yet another leak..

HERE

There are some critical inherent issues that must be dealt with properly or Darla’s build is going to end up being a wet moldy mess.

Cargo trailers due to the nature of their design will have thousands of rivets holding the outside aluminum skin on, all it takes is one rivet being slightly loose or the caulking cracking and it is no longer a water proof method.

Cargo trailers typically use 4x8 ft sheets of aluminum for sidewalls and even the roof, this leads to another problem.. Water proofing the joints..

A sealant could be applied during construction at the joints but after it has been a few years that sealant now becomes an incessant and continual source of hidden leaks..

Once the sealant starts breaking down you will have random leaks which are going to drive you crazy and fixing them properly would require drilling out rivets and lifting the joint to reapply sealant..

Then there is the roof to sidewall and sidewall corner connections… Yep, same problem…

Additionally there is a massive issue with sweating or condensation inside, this needs to be dealt with before the interior walls are put in place..

The aluminum skin and studs if the outside is cold will gather and condense moisture from the warm air inside. Pretty much creating a rain storm inside. I have a garage with a all metal roof and even with good insulation under certain weather conditions I get one heck of a rain storm inside the garage..

Metal wall studs create an additional problem.. No thermal break, yep, those wall studs if you mount your inside paneling will suck the heat out in the winter and in the summer will turn the trailer into an oven.. You have to create a thermal break by using wall studs which are not thermally conductive over top the metal studs or you have to install extra metal studs which do not touch the exterior studs or wall material.

Cargo trailers typically do not have any seals at the doors, this allows for natural air movement exchanging inside air for outside air reducing the possible condensation from being a huge problem.

Darla will need to make the cargo trailer nearly air tight if she wants to reasonably heat and cool the trailer.. She does not have windows for allowing cross ventilation nor any roof vents..

She picked too large of a A/C unit which will not be effective for reducing the moisture so she most likely will need to buy a dehumidifier and run that in conjunction with the A/C unit. This will add unneeded cost, wasted space and not to mention LESS reliability (I use a dehumidifier in my home basement and I average two years out of a dehumidifier at $275 each).

“. It's not something the majority of RVs would want but from reading her blog and the posts on this thread, I'm believe that she's going to be living in the trailer fulltime for years with no intention of selling it. I certainly don't agree with all of her ideas but I'm very interested in seeing the finished product and how she likes it after a few months or years of living in it. “

It will be interesting to say the least.

But over time Darla WILL run into a lot of the same leak issues that RVs get but unlike a RV will not be as easy to detect OR repair.

“Obviously we all have different wants and needs-just look at how many different types of RVs are manufactured. But what Darla wants isn't being made so custom is a good way to get it. I'm not sure where all of the animosity on this thread is coming from. It doesn't make sense to me to get angry about something that doesn't affect you. :-) “

There is nothing wrong with a custom build, but if you want it to work correctly and not have to do over several times it is best to do it “right” out of the starting gate. Part of getting it right is to stop and pause a moment with a open mind and be willing to adjust your design as others point out short comings (after all.. Darla DID ASK FOR HELP).

As in anything we do, it is ALL about compromise, there are things that just can not be helped and must be changed in order to make the entire project work.. It is called compromise.

Often our “plans” look good on paper but when they are being built you find things which just don’t work as you expected. This often creates very expensive changes and if the plan progressed to far it may not be changeable.

When others with experience tell you something in the design isn’t right or won’t work as designed you better stop and rethink your design..

There ARE a lot of things Darla has designed which from my own experiences I know are not going to work as well as expected but alas pretty much anything that has been posted stating so has fallen on deaf ears.. You just can’t teach others with closed minds, kind of reminds me of parenting kids (have a 14yr old “teen” right now that “knows” more than us parents)..
tonyandkaren
Explorer
May 19, 2014
Gdetrailer wrote:

The following document is my second and current rebuild, it took me 2 1/2 years to do, worked on it nearly every night and weekends.

KOMFORT REBUILD

Nice job on the trailer rebuild Gdetrailer! Your experiences with factory built trailers shows why some people such as Darla chose to build using a cargo trailer. No doubt her trailer will weigh more and be expensive but she's getting a very solid, practically leak proof base to finish out exactly as she wants it. It's not something the majority of RVs would want but from reading her blog and the posts on this thread, I'm believe that she's going to be living in the trailer fulltime for years with no intention of selling it. I certainly don't agree with all of her ideas but I'm very interested in seeing the finished product and how she likes it after a few months or years of living in it.

Obviously we all have different wants and needs-just look at how many different types of RVs are manufactured. But what Darla wants isn't being made so custom is a good way to get it. I'm not sure where all of the animosity on this thread is coming from. It doesn't make sense to me to get angry about something that doesn't affect you. :-)
OhhWell
Explorer
May 19, 2014
http://www.coolrunninghs.com/ls090hxv.html
Gdetrailer
Explorer III
May 19, 2014
myrvplans1 wrote:
gdetrailer wrote:
I speak from the experience of tearing down and completely rebuilding not one but TWO TTs.

Any chance we can see pictures from your 2 rebuilds? I am eager to see with my own eyes a model of quality workmanship. How bout it? -Darla

The following document is my second and current rebuild, it took me 2 1/2 years to do, worked on it nearly every night and weekends.

KOMFORT REBUILD

Google plays havoc with the photo quality. To see the photos better you will need to download the PDF to your PC and then open with your own Adobe reader..

I only have a couple of pix on the first rebuild, I was so upset when I discovered I was snookered by the seller I didn't bother taking much in photos. The rot was so bad that every upper cabinet had to be removed and I built all new cabinets from scratch.

You can't buy the knowledge I learned and it is what you are missing, without understanding what is under the hood you will be making rather expensive mistakes.
Huntindog
Explorer
May 19, 2014
A couple of thoughts. Are you stuck on 15'?
It occurred to me that since most building materials are 4x8 standardized, that making the TT box 16' would likely yield some savings in labor, and not add any to the cost of materials. Most of the materials cut off over 15' will just be thrown away, and you would be paying someone to do it!. An extra foot would not be noticed at all when towing, but could make a substantial impact on the interior, at basically zero cost.
It may not work out to exactly 1 foot of extra room, and you would have to have the cargo trailer selected in order to plan it that close.
You would hate to be a inch short in the materials.
But some detailed construction planning couild pay some dividends.

In another post, we talked about how to handle the rear door. IIRCC, you said that the trailer builder could just wall it off.
I think that keeping the doors, if they are the swing open type could have some advantages.
First off it would keep the stealth mode consistent with your desire to not look like a camper.

Next is it would make the construction a LOT easier. If the rear is walled off, then everything will need to be brought in thru the small entry door. This will slow things down considerably and drive up the labor cost.
You could make a sort of false wall back there for when the doors were open, or have a screen wall like some toy haulers have. Might be nice sometimes to have some extra ventilation
Another thought: If you got a ramp rear door, you could use it as a patio. I have even seen pics of a toy hauler with this setup with the ramp hanging out over a lake, so that they could fish off of their own "dock" It looked pretty cool

Finally with the raised floor plan, if the rear doors were still there, you could access the area under the floor just by opening the doors. The possibilities here are endless. You could install some of those long slide out drawers like some camper shell kits have. One could even store one of those fold up canoes in there. Obviously, some of this space will be occupied by tanks etc. so thinking this out in advance would be necessary.
thomasmnile
Explorer
May 18, 2014
myrvplans1 wrote:

Geez, after reading that I think we should drag Darla out by her ears, string her up and stone her! :-) -Darla

Yeah, let's tar and feather her too.

Seriously, hope your plan works as you envision it. Learned long ago this forum can be a tough 'club' to play. Don't be deterred, chase your dream. If things don't work as planned no one here got hurt.