MEP design in Hackney

Terraces, flats and the problem of airtightness

A terraced house here sold for £960,633 on average, a flat for £524,885. Owners are investing in homes that cost a lot to buy, and only 24.6 per cent of households own theirs, so many of our clients are leaseholders asking what they may change within their own flat.

Airtightness is the trap. Insulate and draught-proof a Victorian terrace, and the old leakage that used to ventilate it disappears. Approved Document F sets whole-dwelling rates by bedroom, from 19 litres per second for one bedroom to 37 for four. We design the fans, ducts and trickle or heat-recovery units to reach them quietly, and we find the duct route in the model before it meets a joist.

Where heat pumps are wanted, the design flow temperature is 55 degrees Celsius at most, and the emitters are sized to suit. In a period terrace that often means larger radiators on some walls, or underfloor loops in a new rear extension.

Controls that decide where services can go

Hackney has 37 conservation areas, and its Article Four directions number 77, covering 197 separate areas. Those directions remove permitted development rights, so a flue, vent or external unit on a front elevation may need an application where it would not elsewhere.

Historic England lists 555 entries in the borough: 8 at Grade I, 30 at Grade II* and 510 at Grade II. A further 40 entries are on the Heritage at Risk Register. When a house is listed, the services route inside is part of the application, and we draw it to avoid cutting into original joists and plaster.

Our design places external plant on the rear elevation or a flat roof, with a note of its sound level and distance from windows. The aim is a layout that reads cleanly in a conservation area and passes a neighbour's scrutiny.

How Hackney is deciding applications

In its latest year the council decided 415 householder applications, granting 84.6 per cent and deciding 91.3 per cent in time. For minor schemes the figures were 689 decisions and 81.6 per cent granted. Those are planning measures. We use them to judge how long the project may wait before building-regulations work begins.

Larger home extensions through prior approval produced 15 grants and 1 refusal in the national returns. The route is therefore used here, and plant on a rear extension has to be considered with the neighbours' windows in mind.

Cost context and what we deliver

Hackney's levy bands differ by zone: £190/m² (Zone A); £25/m² (Zone B); £55/m² (Zone C); £0/m² (Zone D). On top of that comes Mayoral CIL at an indexed £72.73 per square metre. A services design cannot change those charges, but it can show early whether a plant-room extension adds chargeable floor area.

The package includes a heat-loss summary, ventilation layout, power and lighting plans, a water and drainage schematic and plant locations, all drawn into one model. We give a fixed quote after a free constraints check, because a flat refit and a full retrofit differ enormously in scope. A second MCIAT chartered technologist checks every set.

Next steps and related pages

Start from architectural drawings in Hackney for the borough's designations, or the general MEP design page for national rules. The services drawings pair with building regulations drawings in Hackney and with SAP calculations in Hackney. Nearby, see MEP design in Tower Hamlets and MEP design in the City of London.