Design

Bee's Needs

A swarm resting on its way to a new home.

Cavity

Bees are very adaptable creatures with minimal shelter requirements. Temperate climate bees need a suitable cavity to over winter in. Few would survive if exposed to the elements. They prefer a nest cavity with the following attributes:

• a south facing entrance.
• 3 to 5 meters above the ground.
• at least 25 liter volume.
• average 40 to 60 liter volume.
• 20 to 40 square centimeter entrance.
• entrance at bottom of cavity.
• 4 centimeter maximum entrance diameter.

Subtropical climate bees prefer smaller cavities of 30 liters. Bees in these climates often eschew cavities and nest out in the open. And they often migrate as conditions or seasons change.

Bees are adept creatures. They can usually find a suitable location in most climates. Cavities, inside trees or rocks, provide enough insulation and thermal mass to moderate conditions whether hot or cold.

In the hottest areas bees often forsake the cavity for a nest in an open, shady, sheltered location.

Different races prefer different volumes. German bees prefer 60 liters. Africanized honeybees prefer smaller cavities of 22 liters.

Mark Winston's "The Biology of the Honey Bee" and Tom Seeley's "The Wisdom of the Hive" are two great books to read about the bee's needs.

Natural Comb

Bees build different types of comb at different comb spacings. Comb used for brood rearing is spaced at 1 1/4". Comb spacing increases as the brood comb transitions into the honey storage comb. It's often spaced up to 2" there.

Bees draw out parallel comb, but not necessarily straight comb. Brood comb will have a slight curve to it, which produces a concave surface that faces the entrance. The rate of curvature increases as the comb transitions from the brood to honey storage.

Bees will easily build a nest structure that is optimal for their health and survival if left to their own means.

Beekeeper's Needs

Spanish paleo beekeeping pictograph.

Beyond what the bees need, a top bar hive must meet a beekeepers needs. After all, it's the beekeeper who needs the beehive and not the bees. They could easily find a suitable cavity and go it on their own. But then we would have to climb that tree or cliff to get them. And it's just much more convenient and safer to bring the bees to the beekeeper, rather than the beekeeper to the bees :>)

Some things to consider before designing a top bar hive:

• purpose.
• skills/tools.
• construction materials.
• migratory.
• management style.
• scale of operation.
• conventional equipment integration.

Criteria

So, the first step in top bar hive design is to prioritize a list of the bees needs.

Then second, list the beekeeper's needs. Keep your list handy and compare any top bar hive design to it. There's no single top bar hive design that is optimum for all bees, climates or beekeeper's needs.

A migratory, extensively managed, large scale, commercial beekeeper would value compatibility, stack ability, portability, optimum conventional material use, and enough volume for maximum flexibility in a top bar hive design.

An organic gardener, needing a few hives for pollination, might value appearance and workability.

And since you have to build one for yourself, build the best one for your bees, climate and needs.