GuideUpdated Sept 2026
How much does an architect cost for a loft conversion in London?
For a London loft conversion the design fee is set by the roof form: a rear dormer sits at the bottom of the range, a hip-to-gable in the middle and a mansard at the top, with ballpark figures for each in the table below. A Building Regulations package typically adds 110–140% of that planning fee. Council fees (£264 for a Lawful Development Certificate, £528 for a householder application), the structural engineer and any party wall surveyor are separate, and the quote tool gives you an indicative figure for your own loft.
GuideUpdated Sept 2026
Class MA office-to-residential conversions in London: a practical guide
Class MA is a permitted development right that lets a Class E building (offices, shops, services) change to C3 homes through prior approval rather than full planning. The building must have been in Class E for two years and vacant for three months, floorspace is capped at 1,500 m² (verify: the rules changed in 2024), the council fee is £250 per new home and the decision period is 56 days. Prior approval tests cover transport, contamination, flooding, noise, natural light and space standards, and Article 4 directions remove the right across much of central London, so check the site before you buy.
GuideUpdated Sept 2026
Conservation areas in London: what they mean for your extension or loft
A conservation area does not stop you extending, but it narrows your options. Roof extensions such as dormers lose permitted development rights automatically, side extensions and cladding are excluded, and many London boroughs add Article 4 directions that remove rear-extension rights too, so most work needs a householder application (8 weeks, £528). The council then judges whether the design preserves or enhances the area's character, which usually means subordinate massing, matching brick and traditional window proportions.
GuideUpdated Sept 2026
Do I need planning permission for a rear extension in London (2026)?
Often not. A single-storey rear extension on a London house is usually permitted development if it projects no more than 3 m (terraced or semi-detached) or 4 m (detached), stays under 4 m high and uses similar materials. Go to 6 m or 8 m under the larger home extension route and you need prior approval (42 days, £120 council fee). You need a full householder application (8 weeks, £528) if the property is a flat or maisonette, sits in a conservation area with an Article 4 direction, is listed, or the design exceeds the limits.
GuideUpdated Sept 2026
Householder planning applications in London: fees, timelines and process
A householder planning application is the route for extending or altering a single house when permitted development does not cover the work. In England the council fee is £528 and the statutory decision period is 8 weeks from validation. You will need existing and proposed plans, elevations, a site location plan, a block plan and usually a short design statement; in London boroughs such as Camden, Richmond and Wandsworth, conservation-area or daylight considerations often shape the design before you submit.
GuideUpdated Sept 2026
Permitted development rights in London: what's allowed and where it's removed
Permitted development (PD) lets you extend a house, convert the loft or build an outbuilding without a planning application, provided you stay within national limits: 3 m or 4 m rear extensions, 40 m³ or 50 m³ of extra roof volume, outbuildings up to 2.5 m high near a boundary. In London the rights are removed or narrowed more often than elsewhere in England: flats and maisonettes have no householder PD, conservation areas block roof extensions, and many boroughs use Article 4 directions to remove specific classes. Check the council's constraints map before relying on PD.
GuideUpdated Sept 2026
How to prepare for a pre-application advice meeting with your London council
Pre-application advice is a paid, non-binding service where a planning officer reviews your proposal before you submit. Prepare a site location plan, existing and proposed sketch drawings, photographs and a one-page brief that names the policies you think apply and the questions you want answered. In London boroughs such as Camden, Islington and Richmond, a pre-app is most useful for conservation-area schemes, two-storey extensions, basements and Class MA conversions, where the officer's steer can save a refusal and a 4–6 month appeal.
