What is Bat Conservation International’s (BCI) certification program?

Many bat houses on the market today are not suitable for North American species because of poor design or construction, and many also lack proper instructions concerning painting, placement, sun exposure, and mounting. In response, BCI has established a Bat Approved Certification Program to help improve the quality of commercially produced bat houses. In addition to the bat houses BCI offers in our catalog, there are now designs from other companies that meet our recommendations.

BCI’s Bat Approved certification will demonstrate to prospective buyers that a bat house is acceptable to bats. Manufacturers can use the Bat Approved logo on bat houses, and in the instructions, packaging, and advertising (for approved bat house designs only). Advertising for approved designs must be reviewed by BCI for accurate content. BCI will provide a letter of certification for manufacturers that can be copied and included with approved models.

We hope this Bat Approved program will encourage manufacturers to design bat-friendly, high-quality bat houses. Those houses which successfully attract bats will further conservation efforts as well as strengthen manufacturers sales. As a result, everyone benefits.

Certification Program

As interest in bats continues to grow, so has the number of bat houses on the market. However, many bat houses are designed and/or constructed such that they are unlikely to be used by bats. Most follow outdated designs which are too small to meet the needs of bats. In addition, instructions for proper installation and treatment are often inadequate. In response, Bat Conservation International created the Bat House Certification Program in 1998 to help manufacturers build high-quality houses that bats will accept.

BCI and numerous volunteer Research Associates in the Bat House Project have conducted years of research to determine which criteria contribute to success. Results show that tall and wide designs offer greater temperature diversity, a key factor in attracting bats. Proper crevice dimensions, roughened interior and landing areas, ventilation slots, and tight, draft-free construction are also extremely important. Because accurate instructions are just as important as having a good design, it is vital that information be enclosed with each bat house sold concerning correct placement, sun exposure, painting, habitat, and other variables.

Manufacturers who wish to earn the Bat Approved certification must submit a finished bat house to BCI for evaluation. Bat houses will be reviewed according to the guidelines below. Only those houses that meet all 10 criteria will be certified. Manufacturers will be provided with a copy of the evaluation and comments.

After a manufacturer submits a model for review, its design, construction, overall quality, instructions, and literature are evaluated. Only those models meeting all of our guidelines will earn certification.

BCI Approved Guidelines for Bat House Design and Construction

1) Roost chambers must be a minimum of 20 inches tall.

2) The width (side to side) of roost chambers must be at least 14″

3) Roost partitions must be spaced 3/4 to 1 inch apart (front to back). The best crevice size for most North American bats is 3/4 inch.

4) Bat houses must possess a suitable landing area. Either a 3- to 6-inch landing area must extend below the entrance.

5) Interior surfaces and landing areas must have adequate texture to provide footholds for bats. such as rough cut wood.

6) Screws, staples, nails, mounting hardware, or other sharp objects (including splinters) must not protrude into roost chambers.

7) Half-inch tall ventilation slots must be provided and be placed no more than 1/3 (one-third) the distance from the bottom. Front vents must be as long as a house is wide.

8) Boards should come from quality stock such as cedar or pine. Any plywood used must be exterior grade (e.g. ACX, T1-11, BCX). Pressure or chemically-treated wood must not be used, as they contain substances which may be harmful to bats.

9) Overall construction must reflect that the bat house is a quality product. Bat houses must be durable and tightly constructed (no unplanned gaps). Caulking or gluing exterior joints is required to prevent drafts. Bat houses must be durable and long-lasting, as they may not be occupied for two years or more.

10) Advertising and any instructions or literature included with bat houses must be approved by BCI. Unsubstantiated or misleading claims (e.g. no more mosquito problems) will not be permitted. Instruction sheets included with bat houses must contain adequate information on painting, sun exposure, mounting height, mounting sites, and recommended distances to water and obstacles.