Solution
In theory, the planning process is meant to involve a meaningful collaboration between people who want to build something and the local authority. In practice, that doesn’t always happen. In this case, though, the council were actively and helpfully involved through both the pre-application and application stages.
We had started off by proposing demolishing what was there and replacing it with an entirely new building. For environmental reasons, the council felt it would be better if we could incorporate some of the shell of the existing building into the new block. As we hope any responsible architectural practice would be, we were happy to respond to that challenge and came up with a design that would reuse as much of what was there as possible while creating something better in every way.
For their part, the council were willing to accept the idea that at that end of the street, houses give way to blocks of flats. So in place of the unhappy original building that did a terrible job of pretending to be a house, we were able to create something that was unashamedly a block of flats (and a rather better-looking one than its neighbours).
The final result was that instead of the original undersized pair of two-bedroom flats, there would now be one studio, two two-beds and a three-bed, all meeting space standards.
We were also able to add some much-needed biodiversity to the plot, with a green roof, bat and bird boxes. So for humans, plants, insects and animals, this is a much better place to live than it was before.