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5 bed new development for sale William Street, Knightsbridge, SW1X

Guide price

£22,500,000

Added on 16/09/2026

Type: New development
Bedrooms: 5
Bathrooms: 5
Size: £4,551 per sq ft
Tenure: Leasehold; 995 years left(from the agent's description)

Council tax Band H £2,099 a year

* From the agent's description. Check it with them before you rely on it.

Key features

Fourth floor, 5 bedroom duplex apartment
Generous terrace and balcony of 419 and 123 sq ft respectively
Impressive ceiling heights
24-hour concierge and security
Grand reception with residents' lounge and outdoor terrace
Storage available by separate negotiation
Price includes furniture

About this property

A masterpiece of mansion apartment living, Knightsbridge Gate is a Grade II listed building with a retained, Edwardian façade, comprising 15 meticulously designed residences. Built in 1902, Knightsbridge Gate is a Grade II listed building originally designed by architect W.D. Caröe for the Church Commissioners. The building retains the original façade in the Edwardian style, which has been painstakingly restored to preserve the heritage and glamour associated with Knightsbridge.

Floorplan

Council tax

Band H £2,099 a year

Per year

Band A

£700
Band B

£816
Band C

£933
Band D

£1,050
Band E

£1,283
Band F

£1,516
Band G

£1,749
Band H

This home: £2,099

This home is in band H, which costs £2,099 a year in Westminster for 2026/27.

Figures from MHCLG (Open Government Licence v3): the average bill for each band across Westminster, including the typical parish precept, so a parish's own bill can differ a little. Discounts lower the bill, such as 25% off for an adult living alone. Check a home's band on GOV.UK.

Price guide

This home

£4,551 / sq ft

Area average (sold)

£2,071 / sq ft

Price per area, sold homes nearby

£1,277 / sq ft

£4,551 / sq ft

£2,916 / sq ft

Lowest

This home

Highest

£4,551 per sq ft, above 9 in 10 recent sales in SW1X (£1,277–£2,916, 10th–90th percentile, 131 sales over 24 months).

Lowest and highest are the 10th and 90th percentiles of 131 homes sold in SW1X over the last 24 months. This home's figure uses its asking price. All sold £/sq ft in SW1X →

Location

William Street, Knightsbridge, SW1X

Open map Street View

Part of a development

This home is in Knightsbridge Gate. See the scheme's facilities, developer and other homes there.

Knightsbridge Gate

APML Estate · Knightsbridge

View development

Mortgage and stamp duty

Property price £22,500,000

£11.2m £33.8m

Deposit10% £2,250,000

£0 £22.5m

Interest rate 4.5%

0.5% 15%

Repayment period 25 years

5 years 40 years

A £20,250,000 mortgage. Most lenders would want a household income of about £4,500,000 to support it.

A guide only, for a capital repayment mortgage. The rate you are offered and what you can borrow depend on your circumstances and a full application with a lender or broker. Your home may be repossessed if you do not keep up repayments on your mortgage.

Properties sold nearby

HM Land Registry sales nearby. Floor areas from Energy Performance Certificates where matched.

Address	Type	Sold	Size	Size	£/sq ft	Price
Apartment 9, 1, William Street Flat / maisonette	Flat / maisonette	Jan 2026	969 sq ft £1,548/sq ft	969 sq ft	£1,548	£1,500,000
Apartment 6, 1, William Street Flat / maisonette	Flat / maisonette	Nov 2025	5,038 sq ft £4,615/sq ft	5,038 sq ft	£4,615	£23,250,000
Apartment 9, 1, William Street Flat / maisonette	Flat / maisonette	Sept 2025	969 sq ft £2,632/sq ft	969 sq ft	£2,632	£2,550,000
Apartment 7, 1, William Street Flat / maisonette	Flat / maisonette	Mar 2024	969 sq ft £2,735/sq ft	969 sq ft	£2,735	£2,650,000
Apartment 4, 1, William Street Flat / maisonette	Flat / maisonette	Sept 2023	3,541 sq ft £4,292/sq ft	3,541 sq ft	£4,292	£15,200,000