If you live near Nightingale Lane and you're trying to work out what rug cleaning should cost in SW12, you're not alone.

If your sofa looks fine but still leaves you sneezing, rubbing your eyes, or waking up a bit congested, you are not imagining it.

If you live in a flat off Balham High Road, you already know the small stuff matters: hallway traffic, limited storage, a radiator drying socks in the corner, and carpets that seem to pick up every crumb, smudge, and bit of street grit.