I downloaded and printed off Building a Top Bar Pallet Beehive by Phil Chandler. I went to: http://www.biobees.com/build-a-beehive-free-plans.php It took 3 pallets and a bit of time, but it's well worth it!
About my Top Bar Pallet Beehive:
First, I dismantled several heat-treated and chemical free pallets. Next, I glued and clamped some of the boards together to make two 36" x 12" boards. These made the sides of the hive, and then I made two 18" x 12" boards for the ends. Additionally, I made the two follower boards the same way by gluing and clamping to the specified shape and size in the plans. I wanted a glass viewing window on one side so that I could peek at their progress without disturbing them, but this was not in the plans.
Next, I used the thicker stringer boards for the legs. I drilled and bolted them on to the main body of the hive when assembled together. The bolts and hinges were the only cost I had and came to about £5.
Top Bar Pallet Beehive - finishing up:
After I cut the top bars to specifications, I pinned and glued the comb building guides. I made a slight change in the plans and decided to make the roof the same way as the sides rather than using corrugated plastic. To keep the roof open I used some metal tent pegs that were hanging around which I bent into large hooks. I sealed the project with natural, bee-safe oils. This was a challenging project I found, and it took me a while as I had no prior experience, no money and hardly any tools. However, it was great fun in accomplishing something that would have cost me a lot of money.
Editor's note: Thank you for mentioning the importance of heat-treated and chemical free wood used in the process. Bees are bombarded by too many toxins on a daily basis. We're seeing significant impact of pesticides and chemicals on the overall bee population. Nicely done! Also a thank-you to biobees.com for making such a detailed build available at a reasonable cost. 1001pallets.com has no affiliation with nor receives any compensation from biobees.com.