Flat conversion drawings in Barnet

Planning route and what the fee covers

There is no permitted development route for dividing a house: Use of a single dwellinghouse as two or more dwellings is a material change of use. Our planning drawings in Barnet set is the base for the application, and the council fee is £610 for each dwelling created.

Barnet decided 703 minor applications in its latest year, which is the class most small conversions fall into. It granted 67.4 per cent and decided 92.7 per cent in time. Householder appeals tell a related story: the Planning Inspectorate decided 413 of them from Barnet decisions and allowed 50.6 per cent. These are borough-wide figures about the council's behaviour, not about your plot.

Space, garden and Green Belt in outer Barnet

Barnet has plenty of houses: 52.5 per cent of households live in one, and 52.7 per cent are owner-occupied. Green-belt polygons cover 28 per cent of the council area, so some conversion candidates sit near open land where extensions needed to make the layout work are harder to justify.

Each flat is also tested against the national space standard. For floor area it says Minimum GIA: 1b1p 39 m² (37 m² with shower), 1b2p 50 m², 2b3p 61 m², 2b4p 70 m² (one-storey dwellings); 3b4p 74 m², 3b5p 86 m². Bedrooms follow their own rules: Single bedroom at least 7.5 m² and 2.15 m wide; double at least 11.5 m², one double at least 2.75 m wide (others 2.55 m). The gardens of 28.1 per cent of the borough's land, as measured in the national land-use survey, mean most schemes can offer outdoor space, and the London Plan asks for Min 5 m² private outdoor space for 1-2 person dwellings plus 1 m² per extra occupant, min 1.5 m deep and wide.

Trees complicate the plan. The council publishes 718 tree preservation orders and 16 conservation areas, so we survey trees on and beside the plot before laying out a bin store or cycle shelter.

Passing the Barnet tests before design starts

The costliest mistake to avoid is paying for a full design on a house that fails the first test. So we work in order. Stage one is a measured survey and a gross internal area figure for the whole house, compared with the minimum in the guidance. Stage two is a count of converted properties on your road. Only then do we draw layouts.

If the house passes on size but the road fails, the answer is not always no. The guidance is a guide, and an application can argue that your plot is different, for example because it sits at the end of a road, faces a main road or is already larger than its neighbours. We tell you honestly when that argument is thin.

If the house is a little under the size line, an extension may bring it over, and the borough householder record is a useful guide to how such extensions are viewed: it granted 80.2 per cent of 1,361 householder applications. A larger house also needs a three-bedroom family flat, so the layout must give one a proper kitchen and garden access.

When a scheme passes both tests we move to detail: shared hall, bin store, cycle storage, and a rear garden split. Our lawful development certificate service can document existing use, which helps if the house has been informally divided before.

Levies and Article 4

Barnet's Community Infrastructure Levy is £361.44/m² indexed 2026 (schedule rate £300/m², residential incl. C2, C3, C4 and sui generis HMOs) and it covers houses in multiple occupation too, so any new dwelling counts. The relevant national rule is that The under-100 m² CIL exemption does not apply where a new dwelling is created. Add the Mayoral charge, band 2 at £72.73 per square metre indexed, and the levies can be a significant part of the project cost.

An Article 4 direction on shared homes also applies in the borough, so if you plan to let rooms rather than create flats, check the position first.

Price and where next

Drawings for a two-flat scheme start at £1,195, VAT included, and we redraw free if the council asks for changes, though we never promise a result. For the other services in the borough see architectural drawings in Barnet. In a different borough with a different test, compare flat conversion drawings in Westminster.