Permitted Development and Planning Permission for Boiler Flues in London: What You Need to Know
Installing a boiler flue on a London property is not automatically permitted development in every case. The location of the flue, the property type, and whether the property is in a conservation area or listed building all affect whether planning permission is required. Getting this wrong can mean an enforcement notice and the cost of removal.
What Permitted Development Rights Cover for Boiler Flues
Permitted development rights in England allow certain minor works on residential properties to be carried out without a full planning application, subject to specific conditions. For boiler flue installations, the relevant permitted development right is set out in Part 1 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015. Under this provision, the installation of a flue on a residential dwelling is permitted development provided the flue does not project more than one metre above the highest part of the roof if installed on the roof, and provided it is not installed on a wall or roof slope that faces a highway and is visible from that highway if the property is a flat, maisonette, or a house in certain designated areas.
For the majority of London residential properties, a boiler flue installed on a rear external wall at first floor level or below, or through an internal wall to discharge on the side or rear elevation, will be permitted development and will not require a planning application. This covers the most common boiler flue installation scenario in London: a combi boiler installed in a kitchen or utility room with a horizontal flue through the rear external wall. The installer does not need to submit a planning application and can proceed subject to satisfying the Building Regulations requirements, which are separate from planning and are discharged through the Gas Safe competent person certification route.
When Permitted Development Rights Do Not Apply
There are several circumstances in which the standard permitted development rights for boiler flues do not apply or are limited in London. The most common is where the property has had its permitted development rights removed by condition. A significant proportion of London residential properties, particularly flats and properties in developments built after 1990, have Article 4 Directions attached to them or conditions on the original planning permission that remove some or all permitted development rights. Where an Article 4 Direction applies, the installation of a boiler flue may require a planning application even if it would otherwise be permitted development. An Article 4 Direction affecting a property can be confirmed by searching the relevant London borough planning records or by making a pre-application enquiry to the local planning authority.
Flats and maisonettes have more limited permitted development rights than houses under the 2015 Order. The installation of a boiler flue on a flat requires that the flue does not protrude above the roof or beyond the external face of the roof slope on a principal or side elevation fronting a highway. For a top-floor flat where a roof-mounted flue is the only practical option, or for a flat where the external walls facing the highway are the only available flue routes, a planning application may be required even in the absence of any Article 4 restriction. London flat owners considering a boiler replacement where the existing flue route is on a principal elevation or where a new flue route needs to be established should seek specific advice from the borough planning authority before proceeding.
Conservation Areas and Listed Buildings
Properties within London conservation areas, and all listed buildings, have significantly restricted permitted development rights in relation to external alterations including flue installations. Within a conservation area, a boiler flue installation on the front elevation, side elevation visible from a highway, or roof of a property requires a planning application for a certificate of lawful development or a full planning application if it does not meet the conservation area conditions. The London planning authorities treat conservation area applications for external alterations seriously, and applications that would have a negative visual impact on the character of the conservation area are likely to be refused. Where a boiler replacement in a London conservation area property requires a new flue, the preferred position is always the rear elevation or a location not visible from any public highway. Prestige Engineers advise London homeowners on flue routing options that comply with planning requirements and carry out boiler installations with flue positions confirmed as compliant before work begins.