Birdhouses in the PNW?

As spring approaches, I'm building a lot of pollinator hotels and natural beehives for my church and possibly some other religious organizations interested in supporting the local environment. One area that I'm ignorant of though is birdhouses. I have no idea where to begin. We'd like to create habitat for more beneficial wildlife, especially in the food forests we're planting.

So, to those of you who are into building birdhouses: Teach me your ways!

I am about to build some from these plans:

http://www.birdwatching-bliss.com/bird-house-plans.html

It's one of the easier plan sets I've come across.

Ooo! That's me! So here's a few things I've learned about bird houses, or technically I think ornithophiles call them nesting boxes. Only some birds will build a nest in a traditional bird house, or a box with a single entry/exit hole. What sets one bird house apart from another and who will build a nest in it is the size of the box, the diameter of the hole, and placement which is generally height from the ground. Bluebird houses are a popular, and they seem to like a box about 5x5 inches, maybe 8 or 9 inches tall, with a 1.5 inch diameter hole about 2/3's the way up the front that is placed 5-6 feet from the ground facing an open grassy area. If it's too close to the ground or too high from the ground, a bluebird may not use it, but another bird might. Another species might use it anyway if they decide to claim it before a bluebird does for example. Ventilation is important with bird houses, and for example some 1/4 or 3/8 inch holes in the four corners in the bottom, and some holes or gaps at the top of the walls just under the roof can provide sufficient ventilation. Having one wall or the roof on a hinge or pivot allows for easy clean out come winter so the house is available for a new occupant the following spring, and to check for things like wasp nests. Some birds won't nest in a bird house that has an old nest in it. Some owls will nest in man made boxes as long as they're big enough, placed some 30 or more feet off the ground on a larger diameter, like 12"+ at 30 feet, older tree in the woods, and they seem to prefer holes that are kinda flat on the bottom with an arch top, like a D on it's side. They seem to like a bar in front of the opening to land on. Owl's are unlikely to nest in a box placed on a lone tree in a yard of field, but maybe there is a misfit owl out that likes to be different and will.

Some birds will not nest in a box with a single entry hole, but will nest in other more open structures. In this post is a picture of a nesting platform I made, and birds like robins and phoebe's are more attracted to this type of structure and may build a nest in it. They tend to like covered ledges. Again, placement is important to attract them.

I would make sure the boxes are easy to open and clean. The conservation group I work for has a lot of bird boxes on our lands. Volunteers manage them and clean them out every fall. The ones that are hard to open are very frustrating. Sometimes baby birds die in the bird boxes or yellow jackets make nests in them so it's good to be able to easily  clean them.

We used to do dormouse surveys and their nest boxes had a hinged top and a small hole facing the trunk of the tree. they were held on by a loop of wire around the tree and the box, so to inspect/clean them you could just lift them a little and slide them up out of the wire. cleaning just meant tipping it upside down and giving it a shake. Most boxes contained dormice if anything, but commonly bluetits and a couple of other birds would take them over, even though the hole was not where you would conventionally think of one.

My only experience with them was the swallow nesting boxes my parents and grandparents have. I loved watching the swallows swoop around and feed their babies and eat mosquitoes!

One thing I remember is that it's important to have more bird houses than you'd think. They will not fill up every nesting box and like having the security of extra nesting boxes.