Bee Hotel - Modular and Extendable

This is a modular, extendable bee hotel for solitary bees such as mason bees and leaf-cutter bees.

Solitary bees are extremely beneficial pollinators, and with just some light work from you can be boosted significantly in your area.

It is partly experimental. Plastic bee houses can suffer from condensation and mould issues, but I have hopefully designed this in such a way to avoid that issue.

May 2026 Update: Mason bees have successfully laid eggs and built cells in 3-4 channels of my hotel. The seem to have preferred to use the wooden houses first, but are quickly filling up this one. A number of channel sizes have been used, which is interesting, as I thought there would have been more of a clear preference. The way they create cell walls reminds me of 3D printing!

Features:

• Infinitely Extendable. Limited by your filament supply
• Multiple hole sizes from 4mm to 15mm to suit multiple bee sizes (More sizes available on request)
• Disassembles for yearly cleaning and harvest
• Includes overhangs to protect cavitys from rain
• Add more layers based on which hole sizes are being used
• Allows airflow to cavities via plate split (hopefully)
• Recommended colour blue, which possibly attracts more bees
• 150mm deep channels which is the optimum length
• Tested ASA print profile
• Roof module includes keyhole for screw mounting

It is recommended you print with ASA filament as the hotel will be exposed to lots of sunlight and rain.

The design decisions are based on this paper: https://link.springer.com/article/10.1007/s13592-016-0477-z

For your first year I would recommend printing a variety of plates with different cavity sizes, then in year 2, print more plates for the sizes that were popular with your bee species. Please feed-back how your year goes so I can make any design adjustments.

Where to put your hotel

Ideally attach your hotel to the sunniest warmest wall or fence in your garden. In the northern hemisphere this would be South to South East Facing.

When to put out your hotel

You should put out your hotel at the beginning of Spring. This is often suggested as April 1st in the northern hemisphere, but a more accurate sign would be to look out for blossom on fruit trees, particularly apple trees, as Mason bees often get pollen from these plants.

When to clean and harvest your hotel

You can leave your hotel on the wall all year and skip cleaning entirely, and the bees will hatch and leave the following spring, but it is healthier to bring your hotel in at the end of Autumn, usually October 1st in the northern hemisphere, to clean it, which will remove parasites and other nasties.

How to clean and harvest your hotel

Cleaning and harvesting is optional but highly recommended

Tools for cleaning:

• A bucket of water with a teaspoon of bleach
• Another container with clean water
• Some waterproof gloves to protect your hands
• A sieve and/or flat sieve
• Paper towel
• A flat head screwdriver or blunt tool that will fit into the channels
  (I will design a print for this soon)

How to clean

• Seperate the plates by sliding them apart from each other. Push from the back.
• Push the cocoons out of the channel and into the bucket using your screwdriver or blunt tool
• Healthy cocoons will float on the top of the water. Other dirt and parasites will sink into the bucket
• Swirl the water gently to help clean and seperate the cocoons.
• Leave the cocoons in the bleach water for at least 5 minutes and no longer than 15.
• Using your sieve, extract the cocoons from the bleach water and rinse in the clean water
• Place the rinsed cocoons on the paper towel and leave overnight to dry
• Store cocoons in a container in a cold place, such as garage or shed for winter
• Wash your plates with clean soapy water and let dry
• Optional extra step: Suspend your cocoons over a gentle torch light and remove any that glow like amber. These cocoons are not viable.

How to release:

At the beginning of Spring, put your cocoons in a release box, which there are 3D designs for online, but any weather proof box or tub with a 1cm hole in the side will be enough. Place in a warm space near your bee hotels, and your cocoons should hatch and start the process again.