L-shaped dormer drawings in Southwark

Article 4 directions and conservation areas in the borough

The council publishes 480 Article 4 directions, and the data lists 480 direction area polygons. Not every direction touches roofs, but the sheer number means the check cannot be skipped. A direction that withdraws roof alterations turns a certificate job into a planning job.

On top of that there are 53 conservation areas, and 919 listed buildings sit within the boundary. In a conservation area: Class B roof enlargements are not permitted development on article 2(3) land. If your road is inside one, an application is the only route and the drawings need a heritage note.

Trees complicate things further. The borough records 724 tree preservation zones, and a protected tree in a back garden can limit scaffolding and crane access for the dormer build.

How Southwark decides householder applications

Southwark decided 558 householder applications in the latest published year and granted 94.8 per cent, with 95.3 per cent decided within eight weeks or an agreed extension. Those are borough-wide figures for every kind of householder scheme.

It would be a mistake to read that as an easy ride. The figure counts only cases that reached a decision, and says nothing about schemes withdrawn before one. A dormer that arrives with a poor junction detail or no heritage note is more exposed to refusal than one that answers the guidance.

Our job is to put the scheme in the first group. Every L-shaped dormer comes with elevations from the street and the garden, a roof plan and the volume calculation.

From the outrigger junction to the fire route

The roof-join exception is what makes the L workable: Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension. We use it to carry the dormer across the outrigger without a step, drawn on a section so the builder sees the valley, the lead flashing and the support steel.

Neighbours on a Southwark terrace share the roof, so notices are part of the programme: Party structure notice at least 2 months before work. The stair has to land somewhere sensible too, and where headroom is short the rule is: Loft conversions where 2.0 m cannot be achieved: 1.9 m at the centre of the stair, 1.8 m at the side (half width).

A second storey of habitable space means a protected escape route: New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30). In a narrow Victorian hall that can mean a change to doors, which is easier to plan on the drawings than to retrofit.

Fees, levy and the Southwark charging zones

There is no fixed price list for L-shaped dormers. You receive a fixed quote after a free constraints check, VAT included, and we redraw at no charge if officers ask for changes.

Southwark charges its own levy on a zone basis: £598/m² (Zone 1); £300/m² (Zone 2); £74/m² (Zone 3). The Mayoral charge sits in band 2 at £72.73 per square metre this year. Whether either applies depends on the new floor area, and we explain it in the next-steps pack before you commit to the build.

Other Southwark drawings and neighbouring boroughs

Where only part of a roof needs work, a plain dormer loft conversion in Southwark may do. A rear box below can sit in the same set as rear extension drawings in Southwark, and the borough overview is architectural drawings in Southwark.

We also draw L-shaped dormers in Lambeth, Lewisham and Tower Hamlets. The national position on the roof type is in our L-shaped dormer drawings guide.