Hi beemum,
I currently live in London but have worked in Singapore in the past. I am planning to move back there with my family within the year. I love London and will be sad to leave, I have some travel bug though and can't seem to stay in the same country for more than 2 years
Major things I think are different between Singapore and England (mainly around London):
cost of buying a house - extortionate in London.
public transport - rather expensive in comparison to Singapore, which is confusing because it's generally old, subject to several strikes a year and breaks down when it rains.
tax - there are various reliefs but you are looking at around a 1/3 of your income as a rule of thumb.
weather - we have had a couple of brilliant summers in London. Global warming and all that. Touch of snow in winter. Nice seasonal weather if that's your thing.
healthcare - getting private medical is really beneficial in the UK (your husband should try negotiate this into the relocation package if not already) especially one that covers your child.
crime - take a self defense class, I can recommend a good one in West London. You have to be careful outside after dark in London. There is a degree of risk on busses and tubes, stations etc from evenings onwards. Don't forget how safe Singapore is in comparison to the majority of countries in the world.
And my favorite thing that I will miss about London; standing in the sun on a glorious summer afternoon with a pint of English ale, watching some massivly important footie game, after a hard days work (or during a hard days work!).
If you have any questions, please let me know.
Make sure you visit Scotland too, Glencoe in the snow is absolutely beautiful.
Scott.