Onefinestay, Rue de Magdebourg II, Paris: Through the (very posh) keyhole

​Onefinestay opens the door to some of the world's grandest homes. Sophie Lam enters an eminent Parisian address

One of the apartment's sitting rooms

Loyd Grossman's rounded vowels (or Keith Lemon's parodic Yorkshire accent, depending on your era and/or sense of humour) ring through my mind as I push open the inconspicuous heavy timber door: “Who lives in a house like this?” To one side of the lobby are lawyers' offices, to the other, an elaborate wooden sculpture by 19th-century Parisian artist Jean Veber that marks the entrance to our pied-à-terre. An antiquated lift heaves us up to the fifth floor where another set of heavy wooden doors opens on to the apartment.

“Welcome home,” our greeter, Marco, beams. And what a home. It is one of Onefinestay's luxurious portfolio of houses left empty for much of the year and let out to paying visitors. Part of the sharing economy lodging revolution, Onefinestay offers a degree more security than many of its competitors; properties are vetted, security deposits are taken, and staff are on hand to welcome and assist. It's not cheap, but when you think a double room at the George V or Le Bristol can cost more than €900 a night room only, these spectacular homes start to look like a bargain.

This apartment sits in the peaceful Trocadéro area of Paris and has a well-known neighbour. As I walk through the dining room to the open, elongated Haussmannian windows and step on to the wrought-iron encased balcony, I am greeted by the top of the Eiffel Tower in plain sight.

One of the apartment's bedrooms

The rooms

A grand piano takes pride of place in the dining room. It belonged to the apartment's former owner, composer Jacques Ibert. Still in the family, this remains an artistic household. Polished parquet floors squeak as I pad around beneath corniced ceilings, taking in an ornate stained-glass window, heavy marble fireplaces and period furniture made cosy with bright fabrics.

There's a painting by pioneering street artist Jérôme Mesnager here, more work by Jean Veber there (also a member of the family) and a library in the sitting room that runs from 19th-century editions such as Rousseau's Nouveau Heloise to a set of Larousse encyclopedias. In another sitting room (why not have two?) there's a trolley teeming with bottles and decanters that's discreetly taped off (Onefinestay labels anything that's out of bounds); while off a peach-painted, wood-panelled corridor is a trio of bedrooms, a bathroom and kitchen. The beds are made up with hotel-quality linen and the bathroom is stocked with L'Occitane toiletries and fluffy towels.

Out and about

All Onefinestay properties come with an iPhone with its own app, detailing everything from local supermarkets and banks to bars, restaurants and places to visit (which we can also use to Mayday head office if there are problems, book an Uber or make free local calls). Before leaving us to it, Marco points out his favourite bars and impresses upon us that there's no need to stray across the Seine to the Eiffel Tower.

Inevitably, that's where we head first (toureiffel.paris). En route, we pass the Aquarium (00 33 1 40 69 23 23; cineaqua.com), the bombastic fountains of the Trocadéro Gardens and Cité de l'Architecture et du Patrimonie (00 33 1 58 51 52 00; citechaillot.fr), home to museums of architecture and French monuments. A short distance east is the Palais de Tokyo (00 33 1 81 97 35 88; palaisdetokyo.com), full of modern art, while across the Seine, the Musee du Quai Branly (00 33 1 56 61 70 00; quaibranly.fr) displays objects from African, Asian, Oceanic and American civilisations.

Food and drink

There's a welcome hamper (Teapigs, coffee, granola, various biscuits and a bottle of Camargue red) from organic foodstore Epicerie Generale, and a bottle of perfectly chilled Piper Heidsieck in the fridge. Onefinestay's app directs us to a chi-chi Monop' supermarket around the corner for further quality provisions, but really, self-catering isn't to be encouraged in such opulent surroundings.

The app is crowded with suggestions such as the excellent Les Cocottes (00 33 1 45 50 10 31; maisonconstant.com) on rue St-Dominique, across the Seine. Part of chef Christian Constant's mini empire – he has several more restaurants on this gourmet thoroughfare – it serves moreish dishes (lamb confit, coquilles St Jacques, caesar salad) in indivual, cast-iron cocottes. Back near the apartment, on Place du Trocadéro, Le Coq (00 33 1 47 27 89 52) delivers unrivalled people-watching – Miu Miu-clad mamans bickering with tearful daughters, plus Zoolander fashionistas – and well-cooked, if expensive, brasserie food.

The essentials

Rue de Magdebourg II, Trocadero, 16th arrondissement, Paris, France (020 7167 2524; onefinestay.com/paris). Rental starts at £953 per night for up to six guests (standard rate, with 50 per cent refund for cancellations) or £1,122 flexible rate (cancellations with a full refund).

Eurostar offers return fares between London St Pancras and Paris from £72 or £189 in Standard Premier (03448 224 777; eurostar.com).