Palomar Mountain Treehouse Construction Project

The off-grid home is completed, the sequoias are planted and growing, along with the 2,000+ cedars, it was time to turn attention to the construction of a treehouse for the grandchildren. We have an ideal location, about 100 feet from the home and in direct view. It took approximately six months to complete the treehouse. I built sub-sections of the treehouse in Poway, then moved subassemblies to Palomar for placement and assembly. The treehouse is off-grid and solar-powered, of course! Title-24 compliant, Platinum LEED certified.

The severe weather (freezing in winter, snow, hail) and winds (gusting to 80 mph) require extraordinary construction techniques, not unlike any home in harsh climates. Construction is done with redwood for rot and insect resistance, metal roof for durability. Not a single solitary nail, all done with wood screws and/or bolts.


Of course, no self-respecting tree house would be without bird houses, so we've added those.
And directional signs let the visitor know where the grandchildren currently reside direction and distance-wise.
And, of course, there is a fireman's pole for quick (or fun) exits from the tree house platform. The pole is 18 feet long. The chain is to stop unintended exits from the tree house platform.
For extra fun as well as speedy exits, there is a zipline to an adjacent tree. Yes, it will hold adults, and it comes with an adult as well as a safety child seat. You can see operation of the finished zipline here. Here is a much more fun and much longer zipline. Another view.
The interior treatments are still in process (furniture, white boards, etc.). Now, on to the construction history...
Construction Start: Perfect location for the treehouse, looking up. The treehouse will be supported by these two cedar trees, each about 20 inches in diameter and about 60 feet tall.
Literally hundreds of hours in design work, some of the many drawings at right. A treehouse sounds simple, but is really quite complicated because each tree is different as well as is the support structure. Many design changes along the way, so a flexible design is essential from the start.
Construction of the ladder from redwood 2 x 4's. Though about twice the cost of more-commonly-used douglas fir, redwood is selected for all of the exposed areas because of its rot and insect resistance as well as the fact that Palomar Mountain is a harsh environment at time (wind, sun, snow).
Sealing the redwood timbers that will form the platform base. Far left are 4" x 6" x 12' beams that will secure the base to the trees.
Metal supports that attach to the tree. Custom welded and fitted out of 1/4" steel stock, these weigh about 50 pounds each.
Several of the 12" long galvanized lag screws that will attach the metal supports to the trees.
Windows for the treehouse.
Assembly of the front wall.
The four walls basic assembly and front door completed and ready for transport to Palomar.
Left: One of many trips moving lumber from Poway to Palomar in our Toyota Sienna. Right: Moving the four walls in a borrowed Toyota Tacoma. I surely miss my F250 for trips such as these!
Delivery of the last load of redwood lumber and plywood.
	At this point, its time to start building the treehouse platform which is likely the most time consuming part. The platform will be essentially a 12' x 12' "deck" , approximately 7' off the ground, upon which the treehouse will be assembled.
The start of the platform support, drilling and installing the steel tree supports.
Base tree support mechanisms in place. Frame is bolted to the tree support at left, right side of frame is "floating" so that the trees can sway relative to each other in high winds. And yes, they do.
Treehouse support frame, nearly completed.
Support frame with vertical railing support beams in place.
Deck surface completed. All timbers are redwood.
Underside of deck showing support mechanisms.
Another top view of the deck surface. The tree at right is floating via the support beams so that the trees can sway without buckling or binding the treehouse base.
Preliminary install and testing of zipline. The testing took more time than expected, it was simply too much fun. You can see operation of the zipline here. Here is a much more fun and much longer zipline. Another view.
The first wall going up using a custom jig and the tractor front loader. The entire tree house was built with one person, me. Some of the required maneuvers were tricky, especially assembling the four walls and putting on the roof.
Two walls up and assembled together. This part of the assembly is the hardest, two walls, each about 100 pounds or more, and only two hands to hold and fasten together!
All four walls up and assembled.
April 26 and it rains and snows...that is snow/ice on the deck. Not good weather to put up the roof, so I wrap it and wait until the weather blows over. Not unlike when I was building our home, just on a smaller scale this time.
Fireman's pole installed at right. Underneath are swings added.
Detail view of the swings.
If you like a longer swing, this 30 foot high swing should do. Its about 50 feet away.
Netting installed for child safety, 12 vdc (solar) power installed for lighting.
After many weeks waiting for "low wind" days, the galvanized metal roof is installed and the tree house completed. No Trespassing except for children under the age of 12 or over the age of 65.
First visit to tree house by Camren and Brennen.
One of the swings underneath the tree house.

Zipline first trial.

finis.