On 31/05/2014 15:25, wrote:
A tree on a housing estate, with sawtooth edged simple leaes. The flowers have a large, pale leaf-like cover with small flowers underneath.

Here are my pictures:
http://www.geograph.org.uk/photo/4004031 - the tree
http://www.geograph.org.uk/photo/4004034 - the flowers, after the fruit has started to set
http://www.geograph.org.uk/photo/4004037 - the leaves, along with what looks like cherry leaf gall or Eriophyes mite gall

Any ideas?

As has already been said, it's a lime (Tilia). It's not Tilia cordata,
in which the inflorescences are either upright or higgedly-piggedly.

The few-fruited infructesences suggest that it's Tilia platyphyllos.

Some years ago I wrote a guide to identifying limes.

http://www.malvaceae.info/Genera/Tilia/Britain.html

--
Stewart Robert Hinsley