Is the concept of spacetime logical?

[Specforces]

Most of you are quoting classic textbook scientific theory, I am viewing this from a philosophical perspective. Ok here's a scenario that will further explain and expound on my point.

I am imagining 2 houses. I live in one of them. My neighbour in the other. I spend the morning measuring my lounge. I write down the measurements. Then something magical happens. My house suddenly grows bigger. But not only does my house grow bigger, so does everything in it, including me and my ruler. I measure my lounge again and write down the meausrements of the bigger lounge. Then my house and everything in it suddenly shrinks back to normal size again. Then I suddenly notice that the two lots of measurements of the lounge are recorded as being exactly the same on my piece of paper. How could this possibly be so when the lounge was so much bigger the second time round?

The answer is of course because I was using a different sized ruler (ie. a different measurement system - although I wrongly 'perceived it as being the same measurement system). It was the measurement systems that changed, not 'length' itself. Length did not get longer.
If my neighbour was to sneak into my lounge and measure it after the growing had taken place, with his normal sized (small) ruler and measured my lounge, his measurement results would be completely different to my second lot.

A parallel analogy could be made of time. And as with 'length' 'time' cannot cannot speed up. We might percieve it as speeding up if we compare experiences in the changes of physical laws (other than time) like me and my house getting bigger. But neither length nor time themselces can change. Only our perceptions change. Just because our perceptions are 'tricked' doesn't mean want they percieved was correct.

Time cannot speed up. Maybe other laws of nature can change in relation to each other - but not time itself.

This raises a further fascinating question. Does time then really exist at all? Or is it just a figment of our perception? Certainly if time doesn't really exist then it can't be said to be able to speed it. If something doesn't actually exist it can't actually be said to 'do' anything.