Administrator Nick Hood said the £20m-turnover firm had been hit by increased competition and low profit margins on large contracts.
He said: "This is a tragedy for a long established name in the construction sector, and of course for its staff and directors."
Hood said that efforts in the last year to find a buyer for the firm had been frustrated by employment protection regulations that protected the company's 200 members of staff.
He said: "Unfortunately, there are very few companies willing to take on the employment liabilities of such a large number of people, when margins are so slim and the commercial risks are so high."
Loweth, a private company that is based in Romford, specialised in the refurbishment and maintenance sectors.
It had a client list that included Barclays Bank, HBOS and the Royal Bank of Scotland.
Hood added: "Loweth is just the latest victim of the ferocious price competition that exists in the construction sector."