Custom Solar Powered Playhouse With Built in DIY Powerwall!

This project started as an idea for a small playhouse for my boys and then expanded and grew, not only in size but in scope with the addition of solar panels on the roof and a DIY powerwall!

The bare frame has been assembled for some time but the finishing touches such as the lighting/doors and windows have really finished it nicely.

The original idea came from scouring the internet for inspiration and found lots of images and ideas and drew from these to create my own design. I never formally designed it in software or highly detailed plans but more did rough sketches and tweaked as i went along, it worked out great but plans would have been much better i think.

The build was done in three parts with the original playhouse shown in the right in the photo and then the slide and climbing wall was added with a hole being added into the playhouse so that the addition could be accessed.

The third and finishing touches during lockdown were to fit the windows and a door as well as finish the electrics/lighting.

I used a combination of new timber and also reclaimed timber from pallets which was mostly used on the base as this would not be seen.

Step 1: Getting Started and Building Up the Walls

I had the pleasure of a blank canvas in the form of a garden with just turf and nothing else to remove. I started with deciding the dimensions of the base and then laying out the timber on my drive to get an idea of final size.

Once i was happy with the size i used concrete blocks as pad stones sitting on a sand base. Each pad stone was checked to ensure it was level and also level with the other pads. The base was then covered with reclaimed wood from pallets.

Once the base was finished i then focused on the walls and again created the structure on my drive and carried the wall around as a whole which sped up construction. Four posts were added to the front at this stage also which would support the front of the porch.

Once the walls were assembled and secured together they were clad with tongue and groove timber which gave a great finish and further strengthened the walls.

The porch area was sanded heavily as the timber was reclaimed, the internal floor did not require sanding as it would be covered later in the build.

Step 2: Getting the Roof On!

I took quite some time on the roof as it's really important to get things right from the start. The design was based around the idea of having the solar panels on the rear side of the playhouse hidden away from view and also south facing which tied in well.

With this required measurement and angle known i mocked up the first roof truss and once i was happy i created five in total. I took time to create a notch so the trusses sat on the walls safely and securely. Once these were finished marine plywood was then used to create a the roof base.

A membrane was then applied on top of the base to ensure a waterproof layer, the strips are laid so that the top sections overlap the lower ones so any moisture will run off rather than be absorbed by the wood. Once the membrane was fully applied the side finishing sections were applied with helped secured the membrane by a slight overlap.

For the final roof covering bitumen tiles were used which gives a great weather proof final layer but also one that looks great. The trickiest part was figuring out how to start. I used a line of tiles upside down to create a solid edge and then worked my way up. Tiles were trimmed at the top as required. The ridge tiles were then created by slicing a single tile into two and then applying in an overlapping fashion.

Lastly i created some wooden guttering to avoid having plastic spoiling the look, this was then ran into a water butt as we may as well put the collected water to good use!

Step 3: Adding Some Solar and Associated Gubbins

The solar setup consisted of two 100 panels initially which was then expanded out to six 100w panels for a total of 600w output. A powerwall was created using reclaimed cells from old laptop batteries. These were housed in 3d printed holders design by paul kennet from New Zealand. Initially the batteries were housed inside the playhouse but were then moved to an outside enclosure. In total there is around 4.5 KwH of storage in the batteries which is enough to keep any garden lights going for a very long time!!

Step 4: Getting Serious With Batteries!

As mentioned previously the battery storage was greatly expanded with a 7s setup which has 24 cells per individual cell. Four of these were connected to create one large module so 96 cells per module to give 672 cells in total. The enclosure was lined with fireproof paint, ideally however a metal enclosure would be better.

Step 5: Fitting Out the Inside

The inside of the playhouse initially had a step to a second level and bare walls. For the finishing the second level was removed and turned into a seat along with the walls being lined and fitted with laminate for a nice finish.

Step 6: It Got an Extension and Fun Bits Added

For the extension a slide was purchased second hand. The dimensions were designed around the fact i wanted extra solar panels on the roof so i bought the panels and worked backwards.

Step 7: Conclusions

It was fun to finish the build and my boys have been able to enjoy it while in lock down with the nice weather. I still have further ideas but have put things on hold for now as it has to stop somewhere lol