fireplaces to burn smokeless fuel. The work counted as an improvement for rent increase purposes under the Rent Act 1957. Eight percent of the cost (net of any reimbursement) could be added to the rent. Decontrol 1957 to 1965 The new Conservative government passed the Rent Act 1957 which decontrolled all the more valuable houses and reintroduced a system of gradual decontrol in a revised form. lt also transformed the method of fixing the maximum rent payable by tenants by introducing a formula based upon rateable value. Coming into effect on 6 July, the 1957 Act immediately decontrolled all dwelling houses and all contracts for furnished lettings of dwelling houses, with rateable values on 7 November 1956 exceeding £40 in the Metropolitan Police District or the City of London and Scotland, and £30 elsewhere in England and Wales; and tenancies granted for a period exceeding 21 years. No new tenancies were to be subject to control, whatever the rateable value of the premises, unless granted to a tenant who was immediately before its creation a controlled tenant of the same premises or premises that included them. Premiums and payments of rent in advance were forbidden to be charged to tenants of premises that had become decontrolled by the Act for a period of three years from the commencement of the Act. A minimum of four weeks' notice to quit was introduced and the Act enabled the exchange of controlled tenancies by agreement of all parties concerned, without loss of security or rent control, The Act used the word "exchange" although "transfer" would have been more apt. The "standard rent" was replaced with a new "rent limit" calculated by multiplying the 1956 Gross Value by a factor determined according to the repairing liabilities of the parties. For instance, where the landlord was responsible for all repairs and external decoration, (the tenant being responsible for internal decoration only) the 1956 Gross Value would be multiplied by two to produce the annual rent limit. Other multipliers were to be used for different repairing and decorating liabilities. The "rent limit" could be increased for rates borne by the landlord and by a reasonable charge for the provision of any furniture or services. The limit was subject to periodic adjustment to take account of changes in the amount of the rates, changes in the provision of furniture or services and for improvements. It could be