Builders constantly letting themselfs in? Making me uncomfortable, do I have rights?

You need to speak to the landlord as it is continuing way past the time you expected ( or the landlord wasn't very clear on timeline) You need to explain that it is not acceptable, they now need to give you 24 hours notice and they are not using your supplies, they need to provide their own or you will bill them, any mess they must clear up, it is no longer an open building site, you are paying rent, living there and they do not have your permission to let themselves in as and when they choose to.

of course you do - start with a door chain - write to your landlord and tell him it is not acceptable for them to wander in and out when they feel like it. I dont think its good security either.

Inform your landlord that, as per the standard lease terms, they can only enter without 24 hours notice in an emergency; and now that the flat is finished, access is not required as an emergency.

Better get educated on renting rules laws regulations where u live.
Here you getting Scammed.
OOH knowledgeable adults know what and how to use Door wedges and interior door locks..
Ask local adults for actual info locally.

Yes, you have rights. Write a letter to the landlord and tell them that they come in at all times and are making a mess they don't clean up. Tell manager that you don't want them in there when you are sleeping. You need to check the property laws of your state and usually can find those on your states web site. Here in Texas landlords have to put a lock on the inside of the door so that you can lock yourself in and here in Texas a landlord also has to give 24 hour notice when anyone is coming in. It would be good to work with the landlord but not at the price of losing your feeling of safety and the right to some privacy. Here's a trick I learned when traveling. I carried a dinner knife with me. It is possible to shove the knife part through the woodwork with the handle left across the door. No one can open the door in when you do that. There are also cheap little metal gadgets you can get at DIY stores that work the same way and they have a little metal piece that flips over the door and locks so that the door cannot be pushed open until you remove it. I would tell the landlord that these people have let themselves in when you were in the shower and when you were sleeping and that is totally unacceptable. When they need to come in, they shouldn't just knock and open the door and come in. I had that happen. I noticed the wine in the bottles in my wine rack was going down. Then one night when my boyfriend was still out, I heard the door open and the laughter of men. They grabbed my wine and left. I told management and they thought it was funny until I told them the next time I am in bed and someone comes in to steal my wine, I will shoot them. I eventually had to just leave. They had no idea how to give service to their tenants and these guys stealing my wine was unacceptable. They were drinking out of my bottles before they just stole them. I asked how to I get reimbursed for what they have stolen and it went straight downhill. It was a new place and only maintenance and my boyfriend and I had keys. The builders may visit but only with proper notice and consideration to you. Put the knife in the door until you can get to a DIY store and protect yourself.