Scratch building question

O-27 isn't "scale".  The items are selectively compressed.  You can build things so they "look right" and not worry about scale per se.  

I'd suggest taking a good look at several Plasticville buildings.....they were on almost

every 0-27 Marx, Lionel, prewar three rail Flyer and two rail "3/16", S flyer layout 60

years ago....doors are closer to O scale, but structures are compressed...to the point

I, on MY layout, decided not to use a collection of severely kitbashed Plasticville stations in wild configurations (two story, L-shaped, etc.) , as they did not fit in with O scale kit built structures.  I kitbashed and selectively compressed that Lionel Rico station kit down to Plasticville size, and reached the same decision.  BUT, with

other kitbashed Plasticville, and there have been some really good models of same

in prior posts on here, and structures scratchbuilt in their format, such as O scale

doors and, maybe, windows, on structures built to those sizes (heights, etc.), all should fit in.

I'm gloing to guess that your interested in scratching a building since you said "lumber"...could be wrong...either way, draw up what you want to build and compare it to your trains...coloradohiraile has a very good point in that if your going to use aftermarket doors and windows, those would be in O scale{1/48} and might seem a tad off if you made a building in a different scale.

Remember that 1/48 scale is equivelent to 1/4" equals 1 scale foot on any ruler...you can buy an architect's ruler or 1/48 scale ruler with correct foot markings per scale foot, but if you can remember that 1/4" equals 1 scale foot{4 scale feet in an inch}you can use a simple ruler too. 

Good for you for trying a scratch build too....too many folks I've seen limit themselves by saying "I can't do that", but when they try, they find out they can. Your only limited by your available tools, supplies, and drawings...everyone can cut and glue!

Show your progress on here...ask questions or advise....give it a shot!

I am thinking about building box cars more than buildings to start with. I think I need to be more clear on my question, sometimes I don't word things the right way.

 On the Kappler website, they have precut lumber to specific scales, and I would like to know how close the S scale is to the Lionel 027 box cars. For instance, Lionel 027 box cars are 9.5 long (excluding couplers) and I would like to know how long a S scale box car is. When I order my lumber, I have to specify a scale. If S scale is too small then I might order O scale and cut it down slightly to fit my needs but I would rather use the S scale precut lumber if it's close enough. Thanks guys.

Grab a traditional size box car and build your own version of it.

Scale off the car for your scratcbuilt car.

I use nice Poplar clear stock from Lowes for the frame, adding as much or as little detail as I want. Start with the trucks you are going to use as it will dictate how you construct the frame, bolsters or not.  Then build up the body. If it comes out really bad take off the trucks, beat it up some and make it a bad order scrap car. Just have fun.

Good idea! i was putting way too much thought into it when I'd rather just build one.

Choosing your media is one of the aspects of scratchbuilding...brass, styrene, wood..everyone has they're favorites. I like styrene. You can use evergreen siding sheets for rail cars, houses or whatever. Only thing is if you want a "wood" look, you need to drag some sand paer over it for grain...or, in your case, use the easier media- wood.

I'd also echo what Dave said, choose a car length you like and copy that...what's the point of building something that everyone else has, but you don't really like?

Build what ya like! Mkae it the railroad you like, paint it the way you like...you see the point...