But if he doesn't you should and he should back you up WHEN they run and complain to him.

It's your house, not a bar to meet up with their friends.

and who does not want the  manipulative Skidult behavioral bullshit.

I agree with both you and DH.  He needs to do it, and if he does not, you need to do it.  It would of course be better if you were side by side providing the message together.  If we are visiting my parents and one of our friends wants to visit, you can be damned sure that I ask first and ask at least a day in advance.  We never do this with my DW's or our friends in her home town when we are visiting her family.  In fact, we do not stay with them. We stay in a hotel and if we are hosting we rent a large conference room.  My DW would be mortified for friends to see how my IL's live.

I agree that it should come from your husband. Having you say it sets you up to be the bad guy. If they get mad at him, he will always be their dad and they will get over it. If they get mad at you, if could drag on and poor (timid or lazy?) DH will be "stuck in the middle!" So it doesn't bother him? Well, it bothers you, and it's your home too. So, if he is too afraid or doesn't want to be bothered with it, you should say something. 

Next time they turn up at the door, tell them that you're not holding open house today and to call before they come over next time to check it's convenient. Then shut the door. If they have a key, change the locks. It's one thing them coming to visit, it's quite another bringing a squad with them to take over the house. This is your home, take it back!

Why did your husband agree that moving from the home they grew up in was the best plan, if he was just going to let them continue to rule the roost in the new home, and not set any boundaries?

I guess if he won't do it, you will have to. Let's face it, even if he said something to them, he's going to throw you under the bus and you will be the bad guy.

The fact that he doesn't mind that they are so disrespectful just shows that he raised them that way.

A right to privacy away from strangers. Never are skids allowed to have friends sleep over. 
my husband wants us and our kids to relax and be comfortable, if skids invite friends for sleepovers expectations is i cater to them (not my bloody job!!) so only once did ss have a college friend come over to "study" which involved them sitting at the sofa looking on their phones web surfing and playing games all friggin day long. 

Your DH is a COWARD. Period.

Sounds like he wants you to be known as the bad guy. He knows they ignore you, as you said they dont converse with you. He knows they dont respect you. He is the good guy to them, but he isnt to you.

Yes he should tell them as he knows they dont like you. BUT he wont, gotta stay in the skids good graces. Thats far more important than staying in yours.

Does he just sit there and watch them be rude to you. ? 

DH should do it! But if he won't, I think you should do it yourself AND THEN remind DH what being a good husband looks like. He should prioritize your happiness. If this is important to you, he should take care of it or do it with you as a couple. Does he generally disregard what's important to you? 

Have your back in all things, especially this.

DH: "children of mine, I need to let you know that if youd like to visit with us, you will need to schedule the day ahead of time, and also, please do not bring extra folks, this is our time to hang out together. Also I noticed that you ignored my wife Brentwood last time, and you will need to show her more respect the next time."

If they have keys, re do the locks. 

It is always on the bio parent to create and enforce boundaries with the skids.

If your DH doesnt do this, well, you need to be prepared to rain holy heck on his head and then do this yourself. Be the Queen of your hive!

If they don't like, they can get out of the house.  If your DH doesn't like it, remind him he is married to YOU, not his children. You DH needs to respect you as well as your incredibly rude stepkids. 

Keep reiterating your boundaries. It took five, yes five years for my DH and his kids to get it. My DH always had an open door policy which I began gently closing from the time we got engaged. Kids would drop in unannounced all the time, raid his fridge, do laundry, and even invite their friends over to visit and do the same. The youngest (38) has stayed with us for months at a time, especially around the holidays. We moved into our new home and a week and a half later here he comes to do some projects for us. There was no start or end time specified. He was here nearly five months for a few days worth of work. Finally I spoke to DH and asked "So what are YSS plans? Do we have a lodger? Will he pay rent? How much longer will he stay?" DH spoke to him without me there so I really have no idea what the actual conversation was but to his credit YSS apologized to me for overstaying and then high tailed it to his sisters for the next three months, then two months with friends out of the country then back to us from Thanksgiving-mid January. DH didn't bat an eye. This was so normal for him. To DHs credit any time I brought up my concerns such as yss invited other siblings over at 10pm one Sunday night to enjoy our new hot tub with him. I overheard the conversation and wasn't sure it was an immediate invite, so when someone came knocking and DH asked who the heck is that at this hour? I told him who I suspected it was. He met them at the door before yss and told his own kids it was to late and that he has work in the morning so maybe another time. I think they were all so shocked that Another time never happened lol. DH like yours would have had no problem with it were it not for me. 
 

I persisted in pointing out that it was not healthy for our relationship with them to not respect our home and relationship with each other and them. It's still ongoing but the entitlement has become less and less over the years, but I also have a very good man who listens to my perspective on these things and puts our marriage first. On the plus side he sees my own adult children who do none of those impositions upon us. Yet have a great relationship with both of us.  So it does make a striking contrast. The first time one of his daughters came and did wash while we planned a leisurely morning I told him if he wants Saturday morning cuddling to continue in the future he needed to have a talk with her about texting or calling first, it's not crazy to want that privacy and respect for your relationship. Funny enough she NEVER did wash at his home again, I don't know if it offended her to have to ask or not but whatever princess. This was NOT the family home either but those things helped me begin to set the boundaries before we bought our home together.

Edit to add: I have as many bio kids as DH and none of them act like this or like DHs having kids or not has zero relevance to the fact that they raised entitled human beings, 

Both of y'all tell them. Ideally he should. 
 

If he's too scared (and why is he scared of his own kids?) then unfortunately you will have too. 
 

Id send those ingrate kids AND their friends invoices (treat my home like a hotel or a virtual office lounge you get charged like one) for their mini bar snacks and their lounge space. 
 

Girl it's YOUR house don't let those kids and their friends run you around. 

It generally said that when it comes to setting/disciplining skids, if the bio won't do it, that leaves it to me and if you don't like the way I do it, then you do it.  
 

That comes into play here.  DH refused to say no so you did it.  You need to make it clear who his wife is, that his marriage is his main priority and that grown a$$ skids are no longer a responsibility ( like they were as kids).  Adult offsprings get treated like all the other adults in your circle.   Sounds like DH is hanging on to his father role to kids and hasn't made the leap to them being adults.   Things change , they are supposed to change.  
 

OP you are not wrong. Stand up for this.  

What is going on at your house that is so inticing? Do you have a pool? I could see one of my grown sons bringing a friend that I knew, someone that they grew up with that is visiting, but they would call first to make sure it was ok with us. What exactly do they do when they are there? At the very least I would make sure there is nothing to eat or drink available. You could also start cleaning wherever they are, vacuum, move the couch cushions, spray furniture polish around, bring a basket of underwear to fold. Sorry, it is your only time for cleaning! 

Period. Dot.

Just no.