That'll do do a normal house, easy. It's a bit expensive though.
I've used a Titan ladder for work for about 10 years now. We have a treble 10" (or whatever is nearest), but a double 11" (two sections, 11 feet each) should do for most 20th century and later houses with standard ceiling heights. The one specced by
@Feek is a double 12", so slightly longer.
I fit CCTV (mostly) for a living, so it's had a lot of use over the years, and I've zero complaints about it. Cheaper than argos too, though I don't know what they charge for delivery.
If you want to use the ladder by yourself (ie without someone to foot it), you can get a reusable anchor kit that will let you strap the ladder to the wall (usually requires a 10-14mm hold drilling). I trust that more than all the fancy apparatus you can get. Ladders are really sturdy when anchored.