The commonest Gulf arrangement in London is a flat or house used for ten weeks each summer and closed for the other forty-two. Since 2025 it costs more, as councils doubled the council tax on second homes and the law removed the nine-month tenancy that used to pay for the summer. This is the yearly cost of a London second home, for a £3,000,000 flat and a £6,000,000 house, and the four ways to handle it.
Owning and letting
A London second home used in summer: the honest running cost, line by line, for twelve months
Summer-use London second home: what it costs to keep ready
A £3,000,000 Knightsbridge flat used for ten summer weeks costs £39,000 to £64,000 a year to keep ready, about 1.3 to 2.1 per cent of its value; a £6,000,000 Kensington house costs £50,000 to £110,000. Both now carry the 100 per cent council tax second-home premium, £6,666 in Kensington and Chelsea. The catch is insurance: a standard policy excludes claims once a home is empty for thirty to sixty days, and a refused claim for a missed inspection is the commonest loss the firm sees.
The family arrives in June; the flat has been aired, the heating checked, the fridge filled by the porter or the housekeeper; ten weeks of London; the family leaves in September; the flat is closed, inspected, and the bills continue. No tenant, no income, and an asset that must be ready on the day the family lands. The cost of that readiness is the subject of this guide. The cost of the alternative, letting the property and staying in a hotel or a serviced flat, is in the last section, and the firm’s view is that more families should make that comparison than do.
Twelve-month cost of a Knightsbridge flat kept for summer use
The twelve-month cost of a £3,000,000 Knightsbridge flat kept for summer use:
Running cost of a £3,000,000 Knightsbridge flat, summer use
| £3,000,000 lateral flat in a portered Knightsbridge block, 2,000 square feet, summer use only | Per year |
|---|---|
| Service charge at £12 to £18 per square foot (porter, lifts, fabric, buildings insurance, reserve fund) | £24,000 to £36,000 |
| Ground rent, where the lease still has it | £0 to £1,500 |
| Council tax, Band H, Kensington and Chelsea, with the 100 per cent second-home premium from April 2026 | £6,666 |
| Contents insurance with an unoccupancy endorsement | £800 to £2,000 |
| Electricity, gas, water on frost and standby settings; broadband kept live | £2,500 to £4,500 |
| Cleaning before arrival and after departure, and monthly while empty | £2,000 to £4,000 |
| Maintenance inside the flat, boiler service, appliances, decoration fund | £3,000 to £8,000 |
| Porter’s and concierge’s gratuities, parcel and key handling | £500 to £1,500 |
| Total | £39,000 to £64,000, about 1.3 to 2.1 per cent of the value |
Source: firm’s indicative ranges, October 2026; council tax from the RBKC 2026/27 Budget and Council Tax Report.
The service charge is the large line and is the price of the porter who makes the arrangement work; a flat without one costs less and needs a housekeeper, which costs more. Our guide on service charges, ground rent and building safety explains how to read the accounts, and our guide on council tax on a London second home the premium.
Twelve-month cost of a £6,000,000 Kensington freehold house
The same twelve months for a £6,000,000 freehold house in Kensington:
Running cost of a £6,000,000 Kensington house, summer use
| £6,000,000 freehold house in Kensington, five bedrooms, garden, summer use only | Per year |
|---|---|
| Buildings and contents insurance with an unoccupancy clause and inspection condition | £5,000 to £10,000 |
| Council tax, Band H, Kensington and Chelsea, with the premium | £6,666 |
| Housekeeper or managing firm: weekly inspection, post, contractors, readiness | £15,000 to £40,000 |
| Gardener | £3,000 to £8,000 |
| Security system monitoring and response | £1,500 to £4,000 |
| Utilities on standby, broadband | £4,000 to £7,000 |
| Maintenance: roof, gutters, boiler, drains, decoration, the garden walls; a house needs £1 to £2 per square foot a year | £15,000 to £35,000 |
| Total | £50,000 to £110,000, about 0.8 to 1.8 per cent of the value |
Source: firm’s indicative ranges, October 2026; council tax from the RBKC 2026/27 Budget and Council Tax Report.
A house costs more in absolute terms and about the same proportionally, and the difference is that nobody walks past the door twice a day; the housekeeper line is the porter line, paid by the owner alone. Our guide on houses or flats for a Gulf family makes the comparison in full.
Council tax second-home premium on a London second home
The council tax second-home premium doubles the bill on a furnished home that is nobody’s main residence, in boroughs that have adopted it: Camden since April 2025, Kensington and Chelsea from April 2026, others deciding year by year. Summer use does not change the answer; a tenant’s main residence or a family member’s does.
What the boroughs charge for the council tax premium
The tables above include it at the Kensington and Chelsea figure; in Camden a Band H house pays about £8,800 with the premium, in Westminster the position should be checked at each budget. A home left unfurnished moves to the empty-home premium after a year, which is worse. Our guide on council tax on a London second home sets out the exceptions, none of which covers a family abroad.
Insurance for an empty London home: unoccupancy rules and cover
A standard policy lapses or excludes claims once a home is unoccupied for thirty to sixty days. The owner must tell the insurer, accept an unoccupancy endorsement (inspection every seven to fourteen days by a named person, water turned off or heating left on, escape-of-water and theft cover limited), and pay a higher premium; in a portered block the buildings insurance is the freeholder’s and the porter’s rounds satisfy the condition for contents cover, which is why flats are cheaper here.
Insuring an empty London house: the housekeeper's inspection log
A house needs the housekeeper’s inspection log. A claim refused because the inspection condition was not met is the commonest insurance loss the firm sees on empty houses. Our guide on insurance for an overseas owner sets out the clauses.
Annual Tax on Enveloped Dwellings if a company holds the home
A flat or house held through a company and used by the family pays the Annual Tax on Enveloped Dwellings: £4,600 a year for a home worth £500,000 to £1,000,000, £9,450 to £2,000,000, £32,200 to £5,000,000, £75,450 to £10,000,000 and upwards in 2026/27, on top of everything above, with an annual return. A £3,000,000 flat in a company adds £32,200 a year to the first table, which is the single strongest reason the firm advises a family home into personal names; our guide on buying through a company or in your own name sets out the rest.
The four choices
Keep it and pay: £40,000 to £110,000 a year for a home ready on the day the family lands, which for a family that values that is the cheapest luxury in London.
Let it and stay elsewhere
Let it fully and stay elsewhere in summer: the rent on the £3,000,000 flat is £8,000 to £12,000 a month, £100,000 to £140,000 a year gross, which pays the running cost twice over and a serviced apartment in Knightsbridge for ten weeks at £25,000 to £40,000; the family loses its own rooms and gains £50,000 to £80,000 a year, and under the Renters’ Rights Act cannot take the flat back for the summer, as our guide on the Act explains.
Company lets, family members and short lets
Let it to a company for its staff on a fixed term, which is outside the Act and can end in June, if such a tenant can be found and the lease allows. Or have a family member live there as their main home, which removes the premium and the unoccupancy problem and changes the property’s whole character. What is not a choice is a short let through a platform, as our guide on short lets and the 90-night rule explains; the lease and the lender will stop it.
Sources: Annual Tax on Enveloped Dwellings (GOV.UK) · Council tax premiums on second homes and empty homes (GOV.UK) · RBKC 2026/27 Budget and Council Tax Report · Renters’ Rights Act 2025 (legislation.gov.uk) Figures verified 14 October 2026.
Frequently Asked
Questions about running a London second home
It is the going rate for a portered prime block; the alternative is £35,000 for a serviced apartment and £100,000 of rent received, and the family must decide what its own rooms are worth. Most of the firm’s clients keep the flat, and should know what it costs.
Water, yes, and the insurer may require it; heating, no, below frost setting, and a flat that goes cold and damp for nine months costs more in decoration than it saves in gas.
A good block’s porter walks past the door, takes the post and will go in on request; he does not inspect. The insurer’s condition needs a named person with a log, which in most blocks is a cleaner or a managing firm engaged by the owner, at the cost in the table.
£6,666 a year for a Band H home, with the 100 per cent second-home premium that the borough applies from April 2026. Camden has charged it since April 2025, where a Band H house pays about £8,800 with the premium; Westminster’s position should be checked at each budget. Summer use does not change the answer, and a home left unfurnished moves to the empty-home premium after a year, which is worse.
£50,000 to £110,000 a year, about 0.8 to 1.8 per cent of the value. The large lines are the housekeeper or managing firm at £15,000 to £40,000 and maintenance at £15,000 to £35,000, since a house needs £1 to £2 per square foot a year. Insurance with an unoccupancy clause is £5,000 to £10,000, the council tax £6,666, the gardener £3,000 to £8,000 and security monitoring £1,500 to £4,000.
Yes, by £50,000 to £80,000 a year. The £3,000,000 flat lets for £8,000 to £12,000 a month, £100,000 to £140,000 a year gross, which pays the running cost twice over and a serviced apartment in Knightsbridge for ten weeks at £25,000 to £40,000. The family loses its own rooms, and under the Renters’ Rights Act cannot take the flat back for the summer. The firm’s view is that more families should make that comparison than do.
Usually not. A home held through a company and used by the family pays the Annual Tax on Enveloped Dwellings: £4,600 a year for a home worth £500,000 to £1,000,000, £9,450 to £2,000,000, £32,200 to £5,000,000 and £75,450 to £10,000,000 in 2026/27, with an annual return. A £3,000,000 flat in a company adds £32,200 a year to the running cost, which is the single strongest reason the firm advises a family home into personal names.
An unoccupancy endorsement once the home is empty for thirty to sixty days: inspection every seven to fourteen days by a named person, water turned off or heating left on, limited escape-of-water and theft cover, and a higher premium. In a portered block the buildings insurance is the freeholder’s and the porter’s rounds satisfy the condition for contents cover. A house needs the housekeeper’s inspection log; a claim refused for a missed inspection is the commonest loss the firm sees.
Yes. The premium applies to a furnished home that is nobody’s main residence, so a family member living there as their main home removes it, and removes the unoccupancy problem with the insurer too. It also changes the property’s whole character. None of the exceptions in the council tax rules covers a family abroad.
No. A short let through a platform is not one of the choices: the lease and the lender will stop it, as our guide on short lets and the 90-night rule explains. A fixed-term let to a company for its staff, which is outside the Renters’ Rights Act and can end in June, is possible if such a tenant can be found and the lease allows.
