The mansion-block flat

The lease, the licence and the managing agent

Most leases prohibit structural alteration and alteration to services without consent, and many prohibit removing floor coverings or altering the floor build-up because of acoustic requirements. A licence to alter is granted on the basis of drawings and a specification, often with a surveyor appointed by the freeholder, a deposit and an undertaking on hours, access and insurance.

Working hours in a mansion block are typically tighter than the local authority's own limits, lifts are usually excluded from use for materials, and access is frequently through a shared hall with a concierge. All of this belongs in the programme before the contract is signed, not afterwards.

Full internal reconfiguration within the shell

Within a mansion-block flat almost anything non-structural is achievable: reconfigured plans within the existing walls, new kitchens and bathrooms in new positions where drainage can be run, bespoke joinery throughout, comfort cooling, and lighting and audiovisual installations designed in from the start.

Lateral conversions between two adjoining flats are common in prime central London and are usually consentable, but the opening through the party structure is structural work requiring the freeholder's consent, an engineer's design and, where relevant, a party wall award.

Acoustics, drainage falls and the unknown build-up

Impact sound between flats is the most frequent source of post-completion complaint. Where a floor finish changes — carpet to timber, or timber to stone — the acoustic build-up has to be designed to meet the lease requirement and installed with the perimeter isolation actually maintained, not bridged by the skirting.

Drainage is the second constraint. Moving a bathroom or a kitchen depends entirely on whether a fall can be achieved to an existing stack, and in older blocks the stack positions and the floor depth are often not what the drawings show. This is worth confirming by survey before the layout is fixed.

The third is the fabric itself: solid concrete or filler-joist floors, ash infill, redundant services and, in buildings of certain periods, materials that require a refurbishment and demolition asbestos survey before any opening up.

Protection, hours and a single point of contact

Flat refurbishments are won and lost on how the building is treated. Protection to the common parts before anything arrives, a named site contact the concierge and neighbours can reach, deliveries scheduled outside residents' peak hours, waste removed continuously rather than accumulated, and dust and noise managed to the licence conditions.

Eternal has carried out apartment refurbishment work in central and north-west London, including two apartment refurbishments at St John's Wood Road NW8 and a four-unit residential scheme at Millway NW7.

Marylebone · Maida Vale · St John's Wood · Kensington · Belsize Park · Primrose Hill

Area pages state the areas we serve. They do not state that a project has been completed in that area.