An investigation is underway into how a million pound five-bedroom house collapsed in West Hampstead on Monday, with builders making a lucky escape.

The London Fire Brigade was on the scene just after midday when 163 Sumatra Road, near the junction with Kingdon Road, collapsed from the roof down to basement level.

The collapse revealed the barren shell of a house inside. Work had been taking place to renovate the property.

Nobody was reported injured, and around ten residents from nearby properties were evacuated as a precaution. They have since returned home, and the road has reopened.

Penny Bowden, was staying nearby and said: “I walked past this morning. It is really lucky nobody was hurt. The foreman said it had been empty at the time of the collapse.”

A spokesperson for the Health and Safety Executive confirmed they were working with Camden Council’s building control department to establish how the collapse happened.

The family house was previously on the market in October 2013 for £1.4million. Flats on the road can regularly be sold for around £650,000.

Camden Council housing department was aware of the property, which it says had been empty for some time.

In April 2014, an application from Jeremy Stein, from Drawing and Planning Ltd, was given permission to excavate and enlarge the existing basement at the property including the creation of two lightwells to the rear,

The planning permission had expired in April 2017, after three years. An appeal was lodged but was rejected in November.

Eyewitnesses said that builders were on site and work was taking place at the property until the day of the collapse. It is uncertain what work was being done.

A spokesman for Mr Stein, who is still registered as the legal owner, said they no longer had a connection with the property.

West Hampstead councillor Phil Rosenberg called for a full investigation “We need to so make sure our processes are robust and neighbours are safe in the long-term.”