History of the Trailer Rear Door

Vintage Trailer HISTORY by Tim Heintz

“Please don’t call it a boyfriend door” – Tim

Does your trailer have a full entry door on both sides? Do you know the real reason for this? Even larger Trailers pre 1951~53 rarely had bathrooms. When you went to a campground or trailer park you backed into your spot and directly behind your parking spot would be a small 8’x8’ block building which was your very own private bathroom, unlike parks today where we share a communal shower house. Trailer industries would put the second door on the street side so you had a very short and private walk out your bedroom to your private bathroom.

By 1951~53 the trailer industry started to include full bathrooms as a standard, which did away with the need of so many bathrooms in trailer parks, not to mention newer trailer parks were adding sewer hook ups and dump stations to accommodate these newer trailers with full bathrooms. In general people like the added feature of a second rear door (mostly for cooling the trailer with a breeze) so the door was just moved to the same side as the front door around 1951/53 industry-wide.

Many of the older parks could not afford to upgrade and went out of business to the newer parks that could accommodate trailers needing full hook ups and dump stations, plus trailers were getting bigger by the year and all these older parks with small block buildings could not fit the larger trailers in their spots without tearing down the only bathrooms they had! While traveling down the older highways today (that use to be major highways in the 1940’s/50’s), Many of you may see vacant grown up lots with small block buildings scattered around…..these are the old abandoned campgrounds and trailer parks from that time period…..I see these all the time here in FL on the old back roads!

And this is why almost all the larger trailers pre 1953 have a door on each side and all post 1953 trailer have both doors on the same side! Below you will see a prime example of this, took me years to finally find such park that still exists that I also had the original published blueprint for; here you can also see how it evolved for larger trailers and eventually to even larger modular homes.

The ad for the park when new shows all the small trailer lots with easy access driveways for backing into the site and the small private block buildings (Full Bathrooms) behind each trailer, however this design example below would allow every two sites to share a private stand alone bathroom (saved on plumbing in the park lol) but as time progressed there was the need with this park (and most others that did not simple close) to enlarge the sites, remove the small private bathrooms for each lot, and seen here today there is only about 65 sites vs the original 92 sites. (FYI this park is now called the Crossroads Park @ 4828 E. Grant Rd Tucson, AZ 85712)


  1. I just love history and this is really enjoyable. It was just the toilet in the private bathrooms, no shower-correct?

  2. Interesting, my ’49 Vagabond had the back door curb side, my ’61 Pathfinder had it curb side and my ’54 Anderson had it street side. I always call it the boyfriend door, my raunchy friends get a big kick out of that term.

  3. Thank you for the History Lesson! I wondered why the rear door went out of ‘vogue’ in newer units. I love the layout in rear door units.

  4. Tim, that’s a great story and truly appreciate the graphic. I will keep my eye out on some of those old major highways back in the Midwest and east, next time we’re in that part of the country – looking for that series of small, block bathroom buildings. Thanks for sharing that historic insight.

  5. Great story, I bought my grandson a beautiful Spartanette with the “Boy Friend Door” when the trailer was restored the side door was incorporated into the bathroom, so if your outside and need to go, no reason to go through the whole traiker

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