5-bedroom flat · SW1A 1NH
For saleListed 79 days
Opportunity summary
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About
A rare opportunity to acquire the penthouse duplex apartment in this discreet, boutique portered mansion building overlooking Green Park. A thoroughbred background in 1959.
The famous racehorse owner and breeder Vera Lilley (nee Sklarevskia formerly Mrs Cottingham), sadly lost her husband Thomas Lilley, chairman of Saxone, Lilley and Skinner - one of Britain's largest footwear companies at that time.
Records also indicate that in 1959, Mrs Lilley purchased well-known Newtown Stud, near Naas in County Kildare, which is now run by the Grassick family, who have their own famous bloodstock line and bred a mare called Vera Lilley in her honour.
As a British racehorse owner, Mrs Lilley was best known in racing history as the owner of the 1961 St Leger Stakes and the 1962 Hardwicke Stakes at Ascot with the winning stallion, Aurelius.
Aurelius was the first horse to ever win at Ascot Racecourse on the flat, over hurdles and in the steeplechase. Then later she bred the top-class racehorse, English Prince.
Meanwhile, in 1959, socialite Mrs Lilley was also working with architects Maurice H J Bebb lriba to create Castlemaine House in St James's Place - a 70-foot-wide site that had been bomb-damaged during WW2 - into her family's long-term legacy.
The plan at Castlemaine House was to create the highest-style boutique lateral mansion block of only six flats, providing all the services for everything you need, including 24-hour porterage, underground parking, and chauffeur's flats, that would be retained entirely by the | family.
By the early 1960s, the building took shape and also incorporated the Queens Passage, connecting Green Park to St James's Place.
This location provided virtually every attribute a growing family could hope for.
Today, Vera Lilley's ancestors have decided that now is the time to sell their final two apartments that have served the family so well.
Castlemaine House today The House Manager lives on site and has done so for over 20 years. His loyal team of staff of almost similar duration.
They maintain the almost Art Deco entrance and reception in a homely manner with a warm smile and are clearly there to help in any situation, the few residents that occupy the building.
The significant main passenger lift is not compromised by a separate core for the service lift and back staircase.
A family from abroad now owns three of the flats, purchasing their last one, Apartment 5, in 2024.
Apartment 1 was sold in 2012 as a development opportunity, which, as the garden maisonette, has been thoroughly transformed to the highest standard.
New managing agents have just been appointed and have a programme of works to undertake to some of the common areas, including modernising the car parking facilities and storage areas.
An enviable location with the best of all worlds Quietly nestled in what feels like a private cul-de-sac, substantial emblematic neighbours like The Royal Ocean Racing Club and The Stafford Hotel, famous for its characterful American Bar, belie Castlemaine House as it is entered via a modest and discreet-looking entrance.
The mid-terrace views over Green Park reassure you that The Ritz on Piccadilly is just to the north, while Buckingham Palace lies just out of sight to the south.
A springboard into Mayfair just to the north or a gentle easterly stroll into the historical St James's Square and Pall Mall, with the West End beyond.
Value & comps
No previous sales on record.
Returns
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Short-let restrictions apply
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Archie refurb estimate: a Pro feature
0.0% below asking
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Deal
Properties like this can earn 2–3x BTL yields when converted to HMO, with retrofit costs around £10k/room. Sign in to see the full tier, yield projection, and cost breakdown.
Commercial properties like this can earn 30-50% higher yields when converted to residential under Class MA / Q / P / PA, with prior approval costing ~GBP 96/unit. Sign in to see the recommended route, yield uplift, and cost breakdown.
BRRR-suited properties can recycle 80-100% of investor capital on refi, leaving a high-yielding rental with most of the money out. Sign in to see the refurb cost stack, ARV projection, and refinance maths.
Detached + large garden = sub-division play. Pro tier unlocks the tier badge, plot size, uplift estimate, and regional land benchmark.
Short-lease flats trade at deep discount, but extending under the 1993 Act often costs far less than the discount. Pro tier unlocks the tier badge, premium breakdown, long-lease ARV and arbitrage maths.
See projected short-stay revenue vs a vanilla BTL for this property.
See real sub-let margins (HMO room rates & SA nightly rates) vs the landlord rent.
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FAQ
About Penthouse,, Castlemaine House, London
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