The Government understands this. While in opposition, Labour taunted the Conservatives with the multi-billion pound cost of repairing the country's crumbling schools. When it came to power, it set about giving schools extra money to spend on rebuilding, and recently it announced the Building Schools for the Future scheme to refurbish or renew every secondary school during the next 15 years.
So the news that all 17 local education authorities in the first wave of this scheme have missed their targets is alarming. Eleven of them are at least two financial years behind schedule. As more schools join the programme, the delays will worsen.
The Government is accusing local authorities of failing to understand the scale of the task, but ministers must take some of the blame. They concede that their controversial Private Finance Initiative has not always met schools' needs. And shouldn't that worrying lack of expertise in big school building projects have been foreseen before those generous promises were made?
Teachers and children have for too long put up with buildings that would have caused a walk-out in most offices: dismal corridors, leaking roofs, cramped and dingy staff rooms. David Miliband, the former schools minister, recognised the link between decent working conditions and decent education.
When he unveiled plans for the scheme in 2003, he spoke of "inspirational, well-designed schools to motivate teaching and learning".
Teachers can and do deliver brilliant lessons in appalling buildings. But a more cheerful environment would make it easier. The Prime Minister's "delivery unit" is looking at ways to improve the scheme's performance. It needs to come up with some quick and effective ways of keeping the Government's promise of a better building for every child and teacher.