My son is 8 and he too strips when he comes home. As long as he leaves his undies on I don't mind. If he gets cold he grabs a blanket. When He goes out he must wear pants but shoes and socks are still optional as long as he stays in the yard. If people are coming over then it is no longer optional, so he has learned it is not appropriate for others to see him in his undies but mom and dad are ok. I know as a child I did the same thing till I was about 10 and then I became more conscious of it and started to lounge in sweats and a t-shirt all day and still do now as an adult. As soon as I walk in the door I change into something ultra comfy.

My six year old comes out of everything after school before the front door close. Everything except his underware and t-shirt. He refuse to sleep in pj's. When company comes over I have to cover him with a blanket. He changes his undershirt at least four times a day. The only time I can get him to put on clothes is to tell him I'm going somewhere. As soon as we get home it starts all over again. He will wear socks because he hates for his feet to touch the floor. He goes through phases, I'll let it run it's course.

We went the other way. We made a deal that she HAS to wear clothes outside our home, but inside, we let her run naked. She's much more comfortable. Since she's gotten a little older (she's 8) we've amended the deal to "if anyone other than Mom Dad or Sis is in the house, you have to either put clothes on, or stay in your room"

Have you tried Occupational therapy? The clothing thing is could be caused by SPD if a SPD child is forced to wear clothes you can cause great discomfort and cause their anxiety to increase which can also cause more issues. There are certain things the OT can do to help acclimate the child to wearing clothes. There are also special websites that sell seamless underwear, socks and other types of clothes for these kids. Here is a website on SPD.
Try to imagine it this way. IF you had SPD and everytime you put clothes on it felt like you were being poked and itchy constantly would you like to be forced to wear them?
That's what my parents used to do to me till the learned I had a sensory problem.

http://www.sensory-processing-disorder.com/sens...

This is a common problem with autistic kids. We simply did not allow him to take off his clothes. No matter what the fits, the clothes went back on. However we also were sensitive to noticing what clothes were comfortable for him.... always removed the clothes label because that bothered him. Tried many types of socks until I finally found the ones that he liked. And continually introduced new clothes so he would be flexible. When he got older, we started letting him pick out his own clothes.... boy, was he happy about that! Giving your child treats when they are successful is also a good practice.

Remember my son is very severe. If we can do it, I know you can. But its important to tackle this when they are young... or you will have a naked teenager which is really big problem.