Garage conversion plans in Merton

Timing a Merton application

The council's in-time figure of 85.2 per cent is the most useful number on this page. It means that, in the latest twelve published months, a noticeable share of householder decisions ran beyond the statutory period without an agreed extension. We cannot change that, but we can plan around it: a complete submission with clear drawings gives officers less to chase, and we answer officer queries promptly.

Nobody can promise a decision date, and we do not. What we do is avoid avoidable delay. We check the planning history for a parking condition before submitting, we show materials on the drawing so a condition does not have to be discharged later, and we say plainly if your timetable is too tight for the route you want. If a builder is booked or a tenant is moving out, tell us the date at the start, because it decides whether we recommend a certificate, an application or a phased job that does the internal work first and the front later.

If your plan fits inside the permitted development rules, the route is a lawful development certificate in Merton, which follows its own statutory timetable.

Conservation areas, listed buildings and the planning route

Merton has 28 conservation areas and Historic England lists 243 entries. In a conservation area a replacement garage front may need an application.

Elsewhere the national starting point applies: Works affecting only the interior, or not materially affecting external appearance, are not development. If the garage remains a garage from the road, there may be nothing to apply for. A new window or a bricked opening changes the elevation, which brings in the usual condition that new materials look like the old ones.

When an application is needed, we prepare it from our planning drawings in Merton. When the real aim is a self-contained space with its own front door, that is a larger project and we would discuss flat conversion drawings in Merton.

Value, levy and cost in Merton

The average home in the borough sold for £615,890 in the latest Land Registry figures, so a garage that becomes a bedroom or a home office adds practical space at modest cost compared with moving.

Merton charges its own levy on new homes at £368.20/m² (Colliers Wood, Raynes Park and Wimbledon); £192.47/m² (Mitcham, Morden and West Barnes). A conversion within the existing walls does not normally add chargeable floor area, but if your scheme also extends the house we flag any likely liability in our handover notes.

Our set costs £695, VAT included, fixed up front. Every sheet is checked by a second chartered technologist, and if the council asks for changes we redraw them free of charge.

Thermal detail for a Merton garage conversion

Garage walls built to store a car rarely meet today's thermal standards. For the new elements Approved Document L says: New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4. These are tight figures for a thin wall, so we test the build-up early and tell you how much floor area and ceiling height the insulation uses.

The details are carried onto the set that building control reviews. See our building regulations drawings in Merton for the full technical package.

Garages in nearby boroughs

Neighbouring councils have different timing and different guidance. See garage conversion plans in Sutton, garage conversion plans in Wandsworth or garage conversion plans in Kingston upon Thames. For the borough overall, read architectural drawings in Merton or the main garage conversion plans page.