There are a large number of ways to clear large areas very quickly in the Technic Pack, such as auto miners, quarries, and the various abilities of Red Matter tools. However, I cannot seem to find any way to automate or speed up building.
Are there any techniques or tools that can accelerate building in the Technic Pack? Prefereably, I'd like it to work on Tekkit, which has a smaller set of mods.
Both Technic Pack and Tekkit include ComputerCraft, which gives you access to Turtles, one of the most wonderful automation tools.
A Turtle is a programmable block just like a computer, but it has an inventory and is capable of movement, digging (when upgraded to be a Mining Turtle), block placing, and sensing its environment and inspecting the contents of its inventory. You might already be familiar with the Mining Turtle's use with macro commands – excavate and tunnel being popular – but since it's a full-fledged a CC computer block you can program it with Lua directly. Giving it a program with a combination of looping, movement, and block placement commands, you can have a Turtle build arbitrarily complex structures.
If you're really ambitious, you could build Wireless Turtles and coordinate them via Rednet from a single program running on a central computer.
(As with most automation, Turtles don't like being unloaded as part of a distant chunk. The usual solution of World Anchors or Teleport Tethers can be useful for long-running construction programs.)
The automatic building tools as part of the Buildcraft mod in Tekkit looks like they do what you want.
Builders consume materials you put in them and create buildings based on a template or a blueprint you give to it. Templates only preserve block position in structures, so the builder will use any available materials to build your structure from a template. Blueprints preserve blocks position and material (although orientation might be messed up), so it's important you provide the builder with the right materials when building your structure from a blueprint.
You create templates and blueprints using a template drawing table. It defines an area where you place blocks to show the shape of the structure you want, then remembers where you placed blocks. Again, if the table draws to a template only position is preserved, whereas with blueprints position and material is preserved.
I'm not sure how practical this is for building a structure only once since template drawing tables require you to place blocks - it might be faster to build it yourself in some cases.
The best machine to use is the filler, as you just make the type of mode you want and give it materials - it will do the job.
