Why is the lag so terrible in town? I can't build my house because of this!
Well, seeing as how vague your question is, my answer may be just as vague.
I'm assuming by "town" you mean Nerdville, Green Hill, Agloe, or another town on the Nerdcrafteria server. Now, lag can be bad for a number of reasons: bad internet connection, a computer under a lot of stress, server issues, and a myriad of other things.
The easiest way to limit lag, on your end, is to exit out of external applications while using Minecraft, such as Skype, Steam, or even your internet browser. By multitasking on a lower-level machine, you can cause yourself a lot of lag.
If that doesn't help much, try installing Optifine*. There are instructions on how to do so in the link provided, but be sure you read through everything if you've never installed a mod in Minecraft before. Optifine has a lot of options that will help you lessen lag, like disabling smoke or fire, animations on water and lava, and particles under water, deep underground, and in Nether portals.
I hope some of this helps you out, and that you can enjoy Nerdcrafteria again soon!
*Note: Please be sure you download and install the correct version of Optifine for what you want to use it for. The server is still on 1.4.2, for reference.