Bromley is one of London's largest boroughs by area, and its housing stock — primarily interwar semis, 1930s detached houses, and Victorian terraces in areas like Beckenham, Penge, and Orpington — is well-suited to rear single-storey and double-storey extensions. RCB Design & Build works across BR1 through BR8 and into the surrounding SE postcodes, including Crystal Palace, Forest Hill, and Sydenham, carrying out rear extensions that range from straightforward kitchen enlargements to full-width rear additions with glazed roofs and open-plan living spaces.
Permitted Development in Bromley: What You Can Build Without Planning
Bromley Borough Council operates standard permitted development rules, which means that on many properties — particularly detached and semi-detached houses — you can add a rear single-storey extension of up to four metres (detached) or three metres (semi or terrace) without a planning application. Under the Prior Approval (Larger Home Extension) route, these limits can be extended to eight metres for detached houses and six metres for semi-detached or terraced properties, subject to a neighbour consultation scheme. This route is increasingly used across Bromley, Beckenham, and Orpington, where plot sizes are generous enough to make a larger rear extension viable.
Double-storey rear extensions do require planning permission in most cases, and Bromley's planning department pays close attention to the impact on neighbouring properties — particularly rear-facing windows and garden overshadowing. Accurate measured drawings and a well-prepared planning statement make a material difference to approval timelines.
What a Rear Extension Project Involves
A typical rear extension in this part of London starts with ground investigation or existing slab assessment, then moves to strip or raft foundations depending on soil conditions. Bromley and the SE postcodes sit on a mix of London Clay and chalk sub-strata — the transition between the two affects foundation depth requirements and is something a local contractor will have encountered repeatedly. The superstructure is most commonly timber frame or masonry cavity wall, with a flat or pitched roof depending on the design and planning requirements.
Internally, rear extensions in this area tend to be specified to create open-plan kitchen-diner-living spaces, often with bifold or sliding doors opening to the garden. Structural steel is standard where load-bearing walls are removed to create the open-plan layout, and this needs to be designed by a structural engineer with calculations submitted to building control. Glazed roofing — either a lantern light or a full pitched glass roof — is common on single-storey additions and adds significantly to the quality of light in a north-facing or narrow plot.
Build time for a single-storey rear extension in Bromley typically runs ten to fourteen weeks from groundworks to plastering. A double-storey addition adds four to six weeks depending on the complexity of the first-floor layout.
RCB Coverage in Bromley and South East London
RCB Design & Build covers Bromley, Beckenham, Orpington, Penge, Shortlands, Chislehurst, Crystal Palace, and surrounding SE London postcodes. The team manages design coordination, planning applications, structural engineering liaison, and construction under a single contract. Credentials include FMB membership, TrustMark registration, and Checkatrade listing.
Considering a rear extension in Bromley or South East London?
Call +44 7359 872594, email contact@rcbgroup.co.uk, or visit rcbgroup.co.uk to arrange a site visit and discuss your project.