Every now and again, you get invited to clean a building and are absolutely blown away by what’s inside. This weekend (September 22-23) it’s the annual Open House London, in which the capital opens its doors to places usually closed off to the public. To celebrate, we’ve picked out those properties which we’d most like to have the pleasure of cleaning…

3 Acorns Retro Eco-house

Any house that’s eco-friendly in our books is great, and 3 Acorns Retro Eco-house is London’s first retro carbon-negative home. The 1840s Victorian terrace house is owned by award-winning environmentalist Donnachadh McCarthy, who believes that when it comes to the looking after the ecosystem, you should practice what you preach. Open House London cites among the house’s energy-saving features “solar electric and hot water panels, wind-turbine, wood-burner, rain-harvester, triple-glazing, solid wall and under-floor insulation.” Not bad, eh?

Abbey Mills Pumping Station

If there’s one person over anyone else to be credited with keeping London clean and hygienic, it’s Victorian engineer Sir Joseph Bazalgette, the man who designed the underground sewage network, which is still used to this day. The Abbey Mills Pumping Station – replete with intricately-decorated portals and Moorish style chimneys – used to be an integral part of this network (today it’s the backup plant to a more modern station), and remains as a fine example of how beautiful buildings can be, even if their job isn’t so glamorous.

30 St Mary Axe (The Gherkin)

On its opening in 2004, 30 St Mary Axe (widely known as ‘the Gherkin’) faced criticism from some quarters, but has come to be an integral shape on the London skyline. This is another eco-friendly building, with a glazed skin with light wells, minimizing the need for electrical lighting during the day. We have to say though, it’d take a fair few hours to clean all those windows!

Banqueting House

Some buildings make you ‘ooh’ and ‘ahh’ as soon as you step inside and Banqueting House on Whitehall is one of these. The 17^th century hall designed by Inigo Jones is the only remaining part of what was Whitehall Palace, and is renowned for its Italianate Renaissance style. To top off its decadence, the murals on the ceiling inside are painted by Dutch Master Rubens. Better use the right cleaning fluids on those paintings…

BBC Television Centre

It’s been at the heart of British broadcasting for 52 years now, but BBC Television centre in White City is soon to be disowned by the BBC, and this is the last chance to see it while programs are still being made here. Just the idea of being let loose in these hallowed corridors is mouth-watering, not to mention the idea of sneaking off to see a recording of a show, or going on a pilgrimage to the Blue Peter garden!