Since their size varies, its hard to give a minimum standards size, but one useful guideline was 4 times the size of your bunny – at the very very least (3). And the guideline also stated if the rabbit is in the hutch for long periods, you must must make it bigger than that.
http://www.rabbithutchesadvice.com/
Rabbit Hutch Length. The hutch should be long enough for your rabbit to take at least 3-4 hops without bumping its nose on the end. A medium sized rabbit covers about 18 (45cm) with each hop-see me measuring/photographing my rabbit Scamp hoping here.
http://www.therabbithouse.com/guide_size.asp
Put bleach water in a spray bottle and also in a bucket. Spray down the cage with the bleach water spray bottle (allows bleach water to get into all corners and crevices). Use the wire brush to scrape off the hard build up areas (usually 1 or 2 spots on the back corner of cage where the rabbit usually urinates).
http://azrabbits.com/useful-information/cages.html
Many rabbit owners automatically place their rabbit hutch in the garden, or outdoor space, thinking this is a good environment for them. Experts in rabbit care give many cautions on using rabbit hutches outdoors, for practical health reasons.
http://www.rabbithutchesadvice.com/
This also allows for plenty of room to turn around. A minimum width of 2' (60cm) is recommended for small to medium sized rabbits and 3' (90cm) for large to giant breeds. The hutch should be long enough for your rabbit to take at least 3-4 hops without bumping its nose on the end.
http://www.therabbithouse.com/guide_size.asp
There are pros and cons to keeping the rabbit hutch outdoors or in the garage. Some owners simply opt to put the hutch in their house or in a porch where the door can be open to the house for more social contact.
http://www.rabbithutchesadvice.com/
Experts believe rabbits are the third most popular pet in the UK today (1). Sadly the hutches sold in many stores are not right for rabbits daily health needs. Find out why they need specific hutches or houses, what they need inside them, how long they should stay in them and where to put the hutch.
http://www.rabbithutchesadvice.com/
Recommended Hutch/Cage Sizes. These recommendations for accommodation size are based on The Rabbit Code of Practice for the Animal Welfare Act 2006 which states: The living area should be as large as possible.
http://www.therabbithouse.com/guide_size.asp
The floor should be 1/2 x 1 14 gauge galvanized wire (galvanized AFTER weld is best) and the sides and top should be 1 x 2 14 gauge galvanized wire. The door opening should be at least 12 x 12, although bigger is nice. Doors swinging inward will keep the rabbits in just in case you forget to latch the door. Doors that open outward will allow you to more easily get inside the cage without pushing the rabbits aside.
http://azrabbits.com/useful-information/cages.html
Because of this, AZ Rabbits recommends you use strong and sturdy all wire hutches. For the NZW sized rabbit breeds, cages should be approximately 36 wide, 30 deep and 18 high (minimum of 30x30x18) for the does and 30 wide, 30 deep and 18 high (minimum of 24x30x18) for the bucks.
http://azrabbits.com/useful-information/cages.html
how big should the door be on a rabbit hutch
A door should be 12 by 12 on a rabbit hutch. The door should be of 12 by 12 in size for rabbit hutch.