M&E drawings in Merton

Valuable detached homes and ordinary semis

In Merton the average detached house sold for £2,338,085, the average semi for £954,064 and the average terraced house for £686,591. Prices moved -0.9 per cent in twelve months, and owner-occupiers hold 55.6 per cent of households. Owners at those values specify heated floors, multiple bathrooms and external heat pumps, and a drawing set helps them hold a builder to what they chose.

The big houses also have big electrical loads: a charge point, a heat pump, a pool pump or a garden building each draw from the same consumer unit. We write the load list on the schematic and check the supply capacity with the owner before the layout is final.

Loft rooms in the borough often end up as the hottest space in a house. A fan with a controlled night purge, a ventilated roof void and openable windows on opposite faces cost little at design stage, and they are the passive measures the overheating tool rewards. The M&E plan shows each one, and the sheet names the fan duty so the installer does not substitute a weaker model.

Planning routes and what they leave for services

Merton refused 80 larger home extension prior approvals and granted 22 in the latest national returns, a heavily skewed result. Householder applications went differently: 92.9 per cent of 759 decisions were granted, though only 85.2 per cent were decided in time. Longer waits are worth planning around, and a services drawing prepared during the wait means building control submission can follow without a pause.

Lawful development certificates are less common, with 58 applications in the same period, so most owners here take a full planning route.

Planning decisions here show a spread between routes, so we avoid using any average to predict a result. What we can control is the quality of the information the council and building control receive, and a coordinated services set is part of that.

Heritage, gardens and external plant

The borough has 28 conservation areas, 243 listed building entries, 11 at Grade II* and 23 Heritage at Risk entries, with 4 registered parks and gardens. Roof plant, a visible flue or a louvre on a street elevation is hard to justify near such assets, so we place them out of sight at the rear.

Domestic gardens cover 27.2 per cent of the borough's land in the national land use survey. A garden that size is room for a heat pump, a garden room supply or a drainage soakaway, and the plan fixes where each goes, keeping clear of boundaries, trees and the neighbour's windows.

The figures we draw to

Approved Document F sets a kitchen with a hood extracting outside at 30 l/s, a bathroom at 15 l/s and a four-bedroom house at 37 l/s for the whole dwelling. A five-bedroom house needs 43 l/s.

Fixed lighting must reach 75 lumens per circuit watt now and 105 under the later edition. Carbon monoxide alarms follow BS EN 50291-1:2018.

Scope, fee and where to read on

A Merton set holds power and lighting plans, ventilation, alarm positions, a consumer unit schematic with load list and drainage notes. There is no published starting price. We run a free constraints check, agree the scope and fix the fee.

Read the borough overview at architectural drawings in Merton, the guide to M&E drawings or the design service at electrical design drawings. Heating and water are described at building services design.