I'm not sure whether things should be saved because they are architectual history. It's not a pretty building and I wonder how much it is liked by the people who live near it. I can't imagine people 50 years from now appreciating it's form.
However I agree that any new building would probably not be any more aestheticly pleasing and probably not of architectual significance.
I went to have a look at the estate a couple of days ago. I don't think it's really possible to pass much comment on these things without seeing the reality for yourself.
The first important thing to understand is its location. In between two major and very busy roads. The two blocks are arranged along the edges of the site and shield the central garden from the noise of the roads. The block on the East side is a bit higher than the block on the West side. To the North of the site is low-rise housing and to the South, some industrial units, then another major road and the elevated DLR. This photo is taken from the DLR station. You can see the two main blocks, with the green space in between:
I think it's worth bearing in mind that whatever replaces it will still have to deal with this rather difficult site and will inherit some of the problems inherent in it.
Obviously I couldn't get inside any of the flats so I can't say much about what they are like inside. But from what I understand, they are quite generous in terms of space and more so than any replacements would likely be.
The buildings are in pretty bad condition, with bits of the concrete facade panels broken off, and window frames not particularly well maintained. In addition to this there have been numerous alterations and additions which are totally unsympathetic to the original architectural intentions. So all this has to be borne in mind when considering how "beautiful" or otherwise the building is, and what it could look like if properly renovated and then properly taken care of.
Anyway, here are some of the things which I think are nice about the building, although these are of course entirely subjective and just my personal opinion:
Both of the blocks have quite a pleasing snake-like form, bending at several points along their length which makes them a lot more humane than many blocks of this era, and also helps to enclose the central garden.
The facades are quite interesting, with a strong pattern created by those vertical elements arranged along their lengths, which are quite pleasing when the sun starts casting shadows across them. The facades are broken up in other ways, for example with balcony recesses. This means they aren't the dismally flat and repetitive and faces presented by most other housing blocks of the time. The facades in particular, I think, have the potential to look a lot better than they do if they were cleaned up and fixed, with windows replaced and so forth.
Possibly the most appealing thing about the scheme - certainly for those not convinced by the merits of concrete-built modernist architecture, anyway - is the generous central garden area, which is very effectively shielded from the noise of the surrounding roads and is a surprisingly tranquil place.
Its main feature is the big artificial "mountain" in the middle which I seem to remember reading was created from the spill created when the estate was built.
There is little chance that a garden of this size would be retained in whatever scheme might replace it.
So in conclusion ... my personal opinion only, of course ...
I don't think it's an outstanding architectural masterpiece of massive international significance. However, I do think it's a nice example of the better end of the range large-scale housing built in that era, and it is fairly unique in a number of ways. I think if kept it would be a useful historical example to have amongst our architectural heritage, (there's as much to be learnt from its failures as there is from its successes).
I think it has lots of potential to be renovated and turned into a pleasant place to live, of equal or better quality to what is likely to be provided as new build.
I can also see that the site has potential to be developed at much higher density, and I can see that there is a lot of money to be made for someone in doing so, and I can see that this fact might just cloud judgements about its architectural merit and also the interests of its current residents.
So I think there is quite a strong argument for listing it in order to prevent its demolition.
We will see what happens.
