If you were to build a new shop...

[AHill]

Dust collection at all major tools.
Air Filters for the floating dust.
Dedicated assembly table to augment the workbench.
Paint booth with appropriate air filtration.
Sink to clean up without messing up the home bathroom and/or kitchen sinks.

[tomsteve]

everything this shop has

https://www.woodmagazine.com/ideas/wood-...1191aa4209

[rayknight]

Mini-split AC, easy to install, no ducts, and new ones have heat unless it gets profoundly low, makes shop realistically useful more of the year (vary with local yearly weather pattern), keep dust cover over the front, blow it off air nozzle, won't  wood-dust contaminate your home system.
Ray

[blanning]

Mini-split AC, easy to install, no ducts, and new ones have heat unless it gets profoundly low, makes shop realistically useful more of the year (vary with local yearly weather pattern), keep dust cover over the front, blow it off air nozzle, won't  wood-dust contaminate your home system.
Ray

That's definitely the plan.  I've installed about 15 split units now and have all the tools.  So that's definitely the way to go.

I was thinking about building a box for an a/c filter around the intake.

The heat works reasonably well for the winter weather here.  But I think it could do with a little more power.  So I'll probably oversize the unit a bit.

[lscraig]

If you were going to build a new shop from scratch, what would you do or not do?

I mean everything, like type of construction, building shape and size, building features, machines to definitely have or avoid... anything.

central dust collection with wall bins
air filtration
layout tables
circulation space around tools and layout tables
lighting and more lighting
quad receptacles every three feet along the walls two separate circuits
shop sinks
finishing booth with filters, proper lighting and air flow
lots of cabinets to organize finishing materials
more lighting
a comfortable chair
a refrigerator
computer with CAD software and large format monitor

[Dave in Denver]

I have both fluorescent and dimmable incandescent lights in my shop so I can see what woods and finishes look like in different kinds of light. Might be good just for your finishing area.

Dave in Denver

[K. L. McReynolds]

Lighting. With LEDs, basic cost is purchase. Install more than you think you need. Especially over major tool stations. Much better to turn off too much light than need more. Example: I installed a 24" led over my table saw. Then found one on either side of the saw top was better. Total cost was $20(4 years ago). That replaces the 4" double florescent lights which had cost more than that $20 to replace tubes.

At least four separate 140v. receptacle breakers. On four plex boxes, use two. Stagger breaker runs. If you use conduit for wiring, do not put all the wiring in one conduit. Use of several circuits in a single conduit can over heat contained wiring. Mount receptacles at 52-58" up from the floor. Use hanging receptacles for machines in the center of the shop.

Outside exhaust for dust collection. Or filter bags outside. Fabricate an in shop air mover/filter. Putting that filter/exhaust outside is a good idea. Really minimizes in shop dust. Plenty of ideas online using a furnace plenum/motor. Locate machines to use same DC piping runs. Minimizes pipe volume and cost. With remote gates, you can shut off one side (if runs on both sides). I use manual gates at each machine, easy to shut off and much less expensive.

Windows are problematic if security is a concern. Having outside DC equipment kinda gives away the interior, so window security is less a concern. Alarm system withy a LOUD siren/signal along with police/fire automatic notification.

Roll up door. Ridge vent and soffits. 5/8" plywood floor. Better for feet, easier to repair. Also easier to add joisting for really heavy equipment. Use station rubber mats.

Lots of tool storage space on walls. Shelves, cabinets, closets, peg boards, French cleats, etc.

[blanning]

Lighting. With LEDs, basic cost is purchase. Install more than you think you need. Especially over major tool stations. Much better to turn off too much light than need more. Example: I installed a 24" led over my table saw. Then found one on either side of the saw top was better. Total cost was $20(4 years ago). That replaces the 4" double florescent lights which had cost more than that $20 to replace tubes.

At least four separate 140v. receptacle breakers. On four plex boxes, use two. Stagger breaker runs. If you use conduit for wiring, do not put all the wiring in one conduit. Use of several circuits in a single conduit can over heat contained wiring. Mount receptacles at 52-58" up from the floor. Use hanging receptacles for machines in the center of the shop.

Outside exhaust for dust collection. Or filter bags outside. Fabricate an in shop air mover/filter. Putting that filter/exhaust outside is a good idea. Really minimizes in shop dust. Plenty of ideas online using a furnace plenum/motor. Locate machines to use same DC piping runs. Minimizes pipe volume and cost. With remote gates, you can shut off one side (if runs on both sides). I use manual gates at each machine, easy to shut off and much less expensive.

Windows are problematic if security is a concern. Having outside DC equipment kinda gives away the interior, so window security is less a concern. Alarm system withy a LOUD siren/signal along with police/fire automatic notification.

Roll up door. Ridge vent and soffits. 5/8" plywood floor. Better for feet, easier to repair. Also easier to add joisting for really heavy equipment. Use station rubber mats.

Lots of tool storage space on walls. Shelves, cabinets, closets, peg boards, French cleats, etc.

All good ideas.  I had heard in the past that if you exhaust your DC outside, you'll have to pull air from outside back into your shop to replace it, causing a problem for the heat and a/c.  But it may not be a major problem since the machines won't be running all the time.  I was planning to make a separate room for the DC and compressor.  Dumping the sawdust outside in a pile would be nice... pick it up with the tractor instead of having to bag it.

Security around here isn't a huge concern.  But it's enough of a problem to warrant the alarm.

[MstrCarpenter]

If I were to build a new shop.... sometime between the plans and breaking ground I would be in divorce proceedings!

I tried to build mine only once; 24 x 48. 2-1/2 stories. Full drive out basement for the greasy stuff. Main level is the woodshop. Front half 6-8" concrete on I-beams 6' o.c. with long span decking, back half floor trusses (for clear span below), 10'-6" clear span ceiling. Top floor mostly storage. 12/12 pitch with rafters on top of floor system gave me about 8' of flat ceiling at 7'6" A.F.F.. (There's a 4' attic above that.)

Leaves and snow would accumulate outside the lower back doors, so when some 20' roof trusses showed up it was a perfect reason to add a "carport". The stone bank would have to be replaced with a proper retaining wall before I could set two piers for the 14" x 20' I-beams. And seeing that I needed concrete for the footings, they might as well come with a full truck and I'll pour a slab too. The radiant heat might have been pushing it a little, but my wife knows I hate to work in the cold.

I know your considering something more modest, so my recommendation is this; Keep planning everything right up to build day. Then complete everything before you move in. I've got my power reasonably functionable, decent lighting, heat, and exhaust fans. But I still don't have a good D.C. system nor permanent air lines. I've been making due with what I have for over 15 years, and have stored all the materials for more than 10!

[Cabinet Monkey]

200A service w/ a 42space panel