Many many many ... MANY ... levels are made with building in mind. I know, however, that many level designers hold a disdain for stages with excessive building (myself included). Levels like "Heaven can wait (we hope!)" and "Pillar of Hercules" make me want to claw my eyes out.
What do you make as alternatives? A few I've seen are about nicely timed digging, bashing, mining. Some are about one Lemming going forward and digging a path backwards. Some are about blowing up blockers or walkers.
What do you do?
I try to keep excessive building to a minimum. I like climbing and mining instead.. it's just as slow, but you can set two climbers off on the start of a level, have one work ahead and have one work back.
Some levels, for instance, No Added Colors or Lemmings show how creative use of skills can be used to make short but sweet levels! They're the sort of levels I try to design.. nobody wants to have a level with an excessive amount of time spent using just one skill. It's boring for the players, and it's boring when testing.
There IS an exception to the rule with building levels. Levels such as Go For It (Fun 22 - Sega Master System) show how building can be used in a different way - the speed of building works to your advantage there.
To sum up... I try to create a mix of building levels and other levels.
It's kinda hard to make a difficult level without using builders. It takes a lot of thinking for me.
I use miners and climbers, and maybe [creative] use of the builder (such as protecting a lemming from splatting).
Builders when used creatively can create an enjoyable level, but when you have to build a mahoosive bridge to go from A to B, you start to get bored. Take a Running Jump is a perfect example of a level which uses builders in several different ways - you turn a lemming around with a builder, you slow other lemmings down with builders, you cross gaps with builders, and you stop other lemmings splatting with builders. There is always going to be the need for a few building levels, but you have to make them as interesting and as challenging as possible! If you master that (which I haven't), you'll be able to make some pretty enjoyable levels!
Short and sweet is good. I like to explore and find new uses for the skills - often this means combining two skills in new and unexpected ways. If that includes builders, then so be it, but more often they're just there to link things together. That said, I have made some levels with a builder focus. "Escape from Alcatraz" is a special case though - this was primarily an exercise in landscaping, with a few lemmings thrown in
Short and sweet is good. I like to explore and find new uses for the skills - often this means combining two skills in new and unexpected ways. If that includes builders, then so be it, but more often they're just there to link things together. [...]
This. Pretty much this.

Builders are not bad per se. The only reason they are worse then bashers, miners, diggers over long distances is that you even have to take care about them, i.e. re-assign them, and they are damn slow. Time should be spent figuring out the solution, not executing it. If a level's amount of builders can be cut without changing the gist of the solution, then it should be done (If the level then comes down to using a builder and being right at the exit, then there was something wrong with the solution right from the beginning). I'd say avoid filler that doesn't affect the solution if not needed, whether it be building, or just long distances. As ClamSpammer said: Short and sweet is good.
I like the builders, just not the long bridge builders!
I think geoo has summed building up perfectly! Heaven Can Wait (We Hope) is slightly different to the other long building levels. The level has a very short time limit, but the amount of building is directly linked to the amount of time needed to complete the level. Fewer builders would make the level too easy! Pillars of Hercules and Hunt the Nessy both use a huge amount of builders for the sake of using a huge amount of builders. I've not met anyone who really likes either of those levels, and I think the reason why people dislike the levels is pretty obvious!
I'm struggling to think of a style which doesn't have a horrible building level. All the styles have at least one evil building level. The Ascending Pillar Scenario, Heaven Can Wait, Lemmings in the Attic, Steel Works and Going Up... are some of the worst examples of building levels.
Try to avoid levels like those listed above at all costs! If you're making a pack of 30 levels, I'd have one long building level at most! They're needed, but they shouldn't be overused!
It's not the style's fault that they decided to give levels with that style the "Curse of the Builder."
True, but it shows that choosing one style over another isn't necessarily going to stop a huge building level being created! Some people may choose the blue style to create levels without as much building. The netting is an excellent way to move your lemmings to the top of a level without having to build, but there is still the potential for a huge building level in there... just like Going Up.
Who said you had to use it to do that?
Look, these building levels are stupid.
That's that.
I didn't think Ascending Pillar Scenario was terrible for being a building level - it was terrible for other reasons, namely 100% requirement and stingy time limit.
Same problem with Heaven Can Wait (We Hope!), only more boring, I bet.
Those levels became extremely lovely once I played them with Fast Fwd. lol.
Dang, fast forward isn't enough for me to accept that kind of level. Try something that works a bit more effectively...
Sorry, not quite followin' ya DullStar?
Sorry, not quite followin' ya DullStar?
Seriously. Do you guys have to make the S capitalized? There's actually a reason why it's not capitalized in my username, and that reason is that it's a lowercase "S."

if this feels a bit harsh, I don't think I've exactly ever mentioned that before, so...
Sorry, it just looks capitalised in the font I use to display web pages in.

Dullstar it is.
You wouldn't be the only one, if I recall correctly, to make that mistake.
I haven't made levels in, well, years now, but I seemed to be obsessed with climbers, probably because they are generally under-utilized and there are tons of puzzles you can make using them. The fact that making a lemming a climber can be both a good and bad thing makes their dynamics really interesting. I try to mix it up, although I do have several levels that involve much building. Really, I don't have a problem with building. The problem is the "hero lemming" concept, with one lemming doing everything (read: building!), paving a way for the others.
Short and sweet levels are the best! There's a time and a place for the longer, more involved (time-wise) levels, but they should be the exception, rather than norm.
Exactly. I don't have a huge problem with hero lemmings if it's not extreme, but...
For those of you who hate build-build-build levels, check out "To The End!" in Lemmings Plus 3.
Basically, in the first difficulty ranking, there's one of the typical worker lemming, build your way (and bash a few other obstacles) levels. Then in the final difficulty, there's a repeat version of it (that's "To The End!") which is almost unchanged - except for the fact you don't have any builders (I think the only other changes were the name (of course), the time limit, and requiring 100% in the repeat).

It basically makes you complete what was previously a builder-abuse level, without using any builders at all.
Then there's that pack I released a while back which took levels from LP1 and LP2, and seriously cut down on the amount of builders, forcing you to find other ways to solve them. Don't know if anyone still has it though.
If it abused builders, how are you supposed to solve it without them?
Try it, and find out.
One of the keys to it is using two worker lemmings at once (due to an actual need for two, not due to time constraints - although that's an issue too, it's simply not the reason for needing two workers), I won't say anything more than this.
A download link would be nice to try it. If you post one, fine, I'll get it and try it, but right now I don't feel like Googling it just for a level test.
However, I'm not TELLING you to put a download link up, it's just easier like that. Your call.
Any luck on it?
I confess to a degree of bewilderment. Yes, "Hunt the Nessy" and "Pea Soup" are annyoing levels that make the game more tedious. But many of the levels mentioned in this topic are nothing of the kind. "Heaven can wait, we hope", "The ascending pillar scenario" -- these only require a few builders, and solving the non-building part of the level is (for someone of the skill level I was when I first reached these levels) interesting and challenging enough to make up for the building part. In "Steel Works" and "Lemmings in the attic" the amount of building is directly linked to the challenge -- in the former, getting up a very irregular cliff face without running out of builders; in the latter, working out how to avoid splatting while the bridge is in progress. I would prefer if some of the levels like this had been cut down -- in "Steel Works" you could remove the middle bit of getting across the water, reducing the number of builders accordingly. But they're not by any means bad or unenjoyable levels.
That's why I try to make sure that in my sets, levels that require lots of builders still manage to be good levels.
I dunno, I can semi agree with you, but I basically think "If it takes more than 3 builders to make one ledge, ditch it". That's because I rather like levels which depend on short bridges being built with good timing.