Last updated: 25 Sept 2019

Being a BH8 is highly advantageous because you automatically gain 84k gold and elixir per day due to of the better collectors. Just by upgrading to BH8 and upgrading collectors, you get almost 3-5 extra leagues worth of loot every day. This makes maxing or overstaying BH7 highly detrimental because you lose a lot of progress. As long as you have lvl14 barbs in BH7, you’re all set to upgrade to BH8.

Read the BH7 Guide here

You builder hall will take 5 days to upgrade, so try to max out your loot by then and try your best to save up a book of buildings/everything right before the upgrade finishes to instantly unlock your new army camp. When I did the upgrade, I got a book of building for the BH and a book of everything for the army camp, instantly catapulting me a few hundred trophies for extra loot.

Note: If you plan to buy the BH8 pack (recommended), you can consider using the book of buildings on the BH itself, buy the pack and use the gems from the pack to complete the army camp.

Once you are done upgrading, I highly recommend you to buy the value pack which costs USD$20 and contains: a lvl4 mega tesla, 3mil gold, 3mil elixir and 2500 gems. Talk about pay to win, but it is definitely enjoyable to cruise up a little bit. I personally didn’t buy the pack because I have so many accounts, but I compensated slightly by saving up books.

First priority upgrades:

1. Build all new defenses, traps and structures at level 1 except for mega tesla, so new double cannon, cannon, air defense, tesla, collectors, push trap, spring trap and mines; all at level 1/2
2. 6th army camp was done first unless you have book of buildings, then do this before waiting on the 5-15min timers in #1. This alone will shoot you up by a few hundred cups so this is a must have
3. With your extra gold, now build your new mega tesla. Skip this if you bought the BH8 value pack. The mega tesla is the strongest defense in the entire builder base, even at BH9. It is also another requirement for your OTTO.
4. Star lab lvl8, get to work on your new level troops quickly, but only after all the most important upgrades are done
5. New gold mine and elixir collectors to lvl7 then all collectors to lvl8. This improves your passive income more than what improving defenses would get you, do focus your builder time here.
6. As soon as you have the elixir, upgrade barbarians to lvl16
7. Elixir storage to lvl8. You will need this for BH9
8. Clock tower lvl8. This will give you a long hefty boost to upgrade times and collector loot.
9. Once barbs are done, upgrade gold storage in preparation of BH9
10. By now, you’re basically done with all your key upgrades and you could upgrade straight to BH9. If you are facing a lot of barb attacks, you may want to upgrade mega mines to lvl6 to try and one-shot them. If night witches are annoying, the only good thing is mega mine lvl8 or high level multi-mortar. I would advice against those things and instead get your lava launcher at BH9 instead to stop witches
11. (optional) builder barracks to lvl10. Super pekkas are kinda good, but only after you finished BM lvl30. While upgrading BM, you may have overflowing elixir, thus upgrading super pekka when you’re overflowing is a good use of elixir. This is something to think about, definitely don’t overstay BH8 just to finish your barracks.
12. Builder Hall lvl9. Once you reach BH9, its time to focus on your OTTO requirements. Remember, one of the main reasons to play the builder base is to unlock the 6th builder. It just so happens that unlocking OTTO is probably the most efficient path in the game.

Lab priority:

This assumes some of your troops are not upgraded yet in BH7, but my guide will recommend you to finish at least barbs

1. Barbs to lvl16
2. Cannon carts to lvl16
3. Super pekka (only excess elixir)

You will need cannon carts at lvl18 for the OTTO and barb + carts is enough to get you there. Once you have these minimum requirements, it is better to spend your elixir on battle machine because he needs to be lvl30. At lower levels, battle machine doesn’t consume enough elixir and it may overflow. So if your battle machine is upgrading and your elixir is full, upgrade pekkas.

Hope this guide helps you out during this transition to BH9. Unlike the main base, the transition into a new level is highly fun and rewarding, if only they can instill this into the main base so that people aren’t averse to upgrading TH. BH8 only serves as a short lay-over because you want to be a strong BH9 instead. Upgrading defenses is unfortunately not going to benefit you much. You are trying to rely on enemy mistakes to beat them, not have your defense overpower their offense.

Read my BH9 guide here