The number of windows, as well as their sizing and placement, depends on your orientation, view, desire for ventilation, and needs for daylight and solar gain. Orienting more of your windows towards the south side of your shop and placing them high enough that they are shaded by the eaves in summer, but allow lower-angle winter light to come in, will increase your ability to get free light and heat from the sun. If your goal is to take advantage of passive solar opportunities, make sure that you carefully research the type of glass that is in your windows and look for something with a high solar heat gain coefficient. Higher windows generally allow for benches and tools beneath them, and relatively win­dowless north walls may be a place to arrange wood storage or mechanicals.

There are benefits to either approach. Sharing a common wall with your house can require some careful soundproofing but can reduce heat loss and exterior fin­ishing costs like siding. A shop located in an addition is more likely to be allowed to have living space or storage space above it, and it may be easier to make use of the existing plumbing and electri­cal and heating systems of your home to service your shop space. Another advantage of an addition is not having to run to an outbuilding in minus-30-degree weather or a summer downpour.

Because workshops are rough and tumble places, the right fan for the job will have an industrial-strength motor and adjustable fan speeds. Easy-to-clean metal blades and a fully encased motor housing are also important features, especially if your shop tends to fill up with sawdust, wood chips and other fine debris. That extra layer of protection will help the fan motor last for years instead of being damaged by particulates.
Perhaps the most satisfying move I made was to automate the dust collection system. I used the iVACPro system to link all machines to the dust collector. When I turn on any machine in the shop, the dust collector fires up and whisks the dust into the bin. The system also has a programmable delay to allow the dust to make it to the bin before the dust collector shuts down. I set my system for a five-second delay. The system works flawlessly for my band saw, planer, and router table at 115 volts, and also my table saw and jointer at 240 volts. 

Cutting thick, rough, warped hardwood can be cumbersome and dangerous. To provide some control over this process, I built a chop-saw station with wings that extend to support long boards. Again, anytime you make something that consumes shop space, make a shelf underneath to gain storage. The chop saw sits in a recess so that the deck of the saw is at the same height as the workstation deck.
Because of my son’s disability and my need to teach him just about everything, I have items sorted into bins with handles, labeled with the category (i.e, Sanding, Cutting, Measuring, etc). It’s over-simplified and over-organized, but necessary in our case. One thing nice about it is that we never waste time looking for something; everything has its place.
One of the best deals on portable power tools, including routers and sometimes planers, comes in the form of factory-reconditioned tools. These are primarily tools that have been repaired at the factory after failing quality inspections or being returned by customers. While they cannot be sold as new, they are identical to new tools in quality and appearance and usually feature the same warranty (be sure to check). Typical savings are anywhere from 15% to 30%, though you sometimes can find even bigger bargains. These tools can be found at and other online tool sellers. It is also possible to buy them through retail stores and, in some cases, directly from the manufacturer’s Web site.
The table saw also works amazingly well as a table. Mine is big enough to not only hold stuff, but serve as an assembly table when necessary. The table of the table saw is set apart from other tables because it is commonly the only one open and available in the shop. I try to keep it clear enough to actually use, which means that at least part of the top is usually available and ready to be used as a table or maybe even a saw.
This is the one tool in the shop that provides the greatest opportunity to save money, if you are willing to purchase a well made, light duty machine, and take lighter cuts. In the past I have used General 14" planers that can hog off seri­ous cuts all day long. The problem is that these professional units cost over $5000, and they would crush my buddy as we haul them down the stairs (note: don’t be the guy on the bot­tom). After doing a fair amount of research, I purchased the Dewalt DW735 13" thick­ness planer. The unit came with a good manual, and was in a good state of tune. It is light enough for me to carry around the shop with­out excessive grunting, so that made it very simple to install. The planer has a sig­nificant internal fan-assisted chip ejection system. The chips are catapulted out of this planer, so have your dust collector running before you run stock through it. I now have to make more cuts at a lighter cut depth, but I saved about $4500, which makes my budget happy. The planer makes clean cuts, and has two speeds. I don’t see a reason for the two speeds for my type of work, but there is a faster feed rate should you choose to use it. Knife changing is simple and quick.
It has made me really think about doing things in an order which optimizes the switching around of machinery. One thing I did do which has really helped and that I would add to your list is SOUND PROOFING! Didn’t mean to yell there.. lol. Sound proofing has has allowed me to keep the workshop operations from bothering the rest of the family when I am in my man-room.
If you live where summers get hot and humid, you may need more than a fan to keep cool in your workshop. Fortunately, air conditioners will both dehumidify and cool your space — and you don’t need a traditional window to get the job done. Instead of a residential window unit, consider a freestanding portable air conditioner that you can use as needed on hot days.
Unless you’re a big fan of frequent shop remodeling, planning the layout of your workshop early in its development will save you a lot of time and trouble and also can keep you from spending years in an uncomfortable, poorly organized space. And if you already work in a shop that’s as organized as a trailer park after a tornado, careful planning and a little remodeling is likely to help you make a quantum leap.