What extracurriculars should I add to appeal to top schools for architecture that are actually simple and attainable?

Answered

Nothing is simple and attainable because when you apply to a good architecture school like Cornell or Syracuse or UVA you have to show some innate artistic and design talent in your submitted portfolio otherwise they will reject you.

None of these schools expect you to submit a building design but they do expect you to have some skills with representing your thought process with regards to a design intent whether you are submitting drawings, renderings, sketches, oil paintings, acrylics, sculptures, pottery, 3-D graphics, comics, or examples of your knitting, or textile pattern designs.

Architecture is a multi-disciplinary major so you need to be good with math, science, art, history, writing, and presentation skills.

For school clubs, I'd probably join robotics, 3-D printing, a vocational shop class in wood-working or metal-working, and if your school has architecture, by all means, sign up for that.

For intellectual vitality, IC, I would probably take some online college classes like Intro to Architecture or an Architectural History course.

For ECs, I would try to get a summer job working for a building contractor because you will learn a lot about how things are put together off a set of plans. Or volunteer for Habitat for Humanity and build low-income houses for the same reason - hands-on experience.

For technical skills, I would recommend learning SketchUp or Revit which are 2 of the most popular design rendering programs. You can most likely get a student license if you look into it.

Most reputable programs are 5 year B.Arch programs. Alternatively you can do a 4 year BS degree but you still have to do 2 more years in grad school to get an MArch if you want to be a licensed architect for a total of 6 years. Many people focus on liberal arts for the first 4 years and then apply to a 3.5-year MArch Program which is an accelerated degree. In the end, all three paths, end up where you need to be. After your schooling, you have interned for 3 years prior to taking the NCARB registration exam so it is a long process.

Unless you are 100% sure, no if and buts, that you want to be an architect, committing to a 5-year degree upfront is no different than entering a BS/MD program right out of HS to become a Medical Doctor.

I would seriously recommend that you apply to a regular college and get a BA or BS in something else before applying to architecture school. Because by the time you are junior you might have changed your mind about it. About 1/2 to 2/3 rd of entering freshmen who apply to 5-year programs end up switching majors and leaving the school and doing something else, so talk to some architects in person prior to committing.