"Going forward blaming is not going to get us anywhere, some areas need more schools,"
Well, we need to know why the numbers are up in order to know where the bulge will be and how long it will last for. Three or four miles away in this city there is massive demand with temporary classrooms in playgrounds; near me, several primaries are on life support and there are upwards of a thousand spare places. Ageing local population, more streets becoming de facto exclusively student housing, etc. But is that pattern going to persist for the lifetime of a new school?
Some countries would solve the problem with bussing: then you only need sufficient places at a larger scale, so 1000 spare places here and a 1000 place shortage five miles away is OK. That's not going to be popular in primary in England. But building schools with fifty-year lifespans is very tricky.
Slapping a school in the middle of a new-build estate of houses is superficially sensible, but what happens in twenty years' time when all the children of the initial purchasers of the houses have moved on? People often buy houses near good schools, but they are much less likely to move out just because their children have finished at that school. In my city, there are a lot of 1960s-build schools with falling numbers surrounded by a collar of elderly residents whose children were the pupils at those schools in the 1970s. A generation or two ago, couples in perfect health living in their own houses thirty or forty years after their children finished school, with none of their children (and therefore grandchildren) living with them, would be unusual; not so much today.