Flat 0414 St. Johns Building, 79 Marsham Street, London, SW1P 4SA

They say good things come in small packages. They also say size doesn't matter. You will never, ever hear an estate agent say either of those things. So - 624 square feet.

There it is, up front, before you went looking for it. Now, what that number doesn't tell you. 414 is a corner apartment. Windows on two sides, and trees in both of them.

The reception looks straight into a canopy of mature planes; so does the principal bedroom. Light arrives from two directions and moves round the apartment all day.

Square footage is what you measure - light is what you actually notice, and this is not a dark 624 feet. It's a bright one, which is a different animal entirely.

It has also just been completely redone. Not freshened up. Redone. New oak floors throughout.

A new kitchen in black shaker with brass handles, its surfaces run in marble-effect porcelain - full slabs rather than tiles, so there isn't a grout line in sight, and unlike the real thing it won't take a stain from the first glass of red anyone puts down.

It's a more serious kitchen than most apartments twice this size bother with. A new bathroom. New furniture throughout.

Recessed cove lighting washing every ceiling, which is the sort of thing people notice without being able to say why. There is nothing here left for you to do, and nothing left for you to spend.

And here's the part nobody mentions in these things. The concierge, the swimming pool, the sauna, the spa treatment room and the gym don't scale with your floor area.

The largest apartment in this building gets exactly the same pool as the smallest.

Which means the less square footage you're paying for, the greater the share of this building you're getting for your money.

Outside: The river four minutes away, Tate Britain five, Westminster Abbey eight, Parliament nine. St James's Park and Pimlico are ten minutes each, covering the Circle, District and Victoria lines.

EPC C. Small package. Same front door.