
Flat Conversion Drawings in Upminster RM14
Fixed-fee, MCIAT-chartered flat conversion drawings for Upminster (RM14) homeowners — London Borough of Havering validation and local constraints handled from the start.
Upminster (RM14) runs from a leafy Edwardian and inter-war suburb down to Corbets Tey, a surviving medieval village and one of the three settlements that originally formed Upminster. The Corbets Tey Conservation Area protects that village character, its listed buildings and its countryside-edge setting, so work there faces close conservation-area control.
Across the wider suburb the housing is mostly detached and semi-detached homes on good-sized plots, and rear extensions, side infills, loft conversions and garden rooms are the usual projects. Havering's householder guidance sets clear expectations, and matching them in the drawings is what gets RM14 schemes through first time.


Planning in Upminster (RM14): what to know before you apply
No borough-wide Article 4 direction affects typical RM14 householder work, so many Upminster houses retain permitted development rights for rear and loft projects. The exception is the Corbets Tey Conservation Area, where the village character, listed group and countryside-edge setting mean external changes are controlled and permitted development is curtailed.
Typical Upminster housing stock
The Corbets Tey village group of listed and historic buildings on the edge of open countryside, surrounded by the Edwardian and inter-war detached and semi-detached housing that makes up most of suburban Upminster.
Streets we regularly draw for in Upminster
Corbets Tey Road · Harwood Hall Lane · Ockendon Road · Hall Lane
What RM14 is actually built of
Measured from 294 classified residential buildings in RM14, not from a description of the area.
Upminster RM14 housing mix
Residential building form across the RM14 postcode district, from 294 classified buildings.
| Attached on more than one side | 25% |
|---|---|
| Attached on one side | 58% |
| Detached | 17% |
| Median building footprint | 82 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.14 |
| Buildings classified | 294 |
Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.
Flat Conversion Drawings for Upminster (RM14) homes: the package and the process
Converting a house into flats is drawn unit by unit. Each proposed flat needs its layout, its floor area, its own entrance arrangement and its amenity provision shown, along with refuse and cycle storage that meets the standards the council applies to new residential units.
The separation between units is the technical core: floors and walls detailed for fire resistance and sound insulation, a common escape route drawn and protected, and services routed without breaching the compartments. Those details go on the drawings because Building Control assesses them there, not on site.
Conversion suits buildings with the plan depth and stair position to make two workable units. A wide terrace or a large semi can usually be split without landlocking a room, while a narrow plan often cannot give both units light, access and separation at the same time.
Do I need planning permission to convert a house into flats?
Yes, always. Converting a single dwelling into two or more self-contained flats is a change from one home to several, and that subdivision is treated as development requiring a full planning application — there is no permitted development route that allows it, regardless of the property's size or whether the exterior changes at all. The application has to demonstrate that each flat meets space, layout, amenity and parking standards in its own right, not just that the building as a whole is being used sensibly.
Boroughs also weigh the loss of a family-sized house against their local housing policy, since converting a larger house into several flats reduces the stock of homes suited to families even as it adds smaller units. We take that policy context into account when advising on layout and unit numbers, rather than simply maximising the number of flats the floor area could technically support.
What sound insulation is required between flats?
Part E of the building regulations sets minimum sound insulation standards for the walls and floors separating flats, covering both airborne and impact sound. Where an existing house is subdivided, the drawings specify how the party floors and walls between units will be upgraded — additional layers, resilient bars, or a floating floor — and pre-completion sound testing is normally required before the flats can be signed off. Getting this detail right on the drawings from the outset matters, because retrofitting sound insulation after a failed test usually means taking up a finished floor or ceiling that has already been decorated.
How do you design fire escape and compartmentation for flat conversions?
Each flat needs its own independent means of escape to a place of safety, and the building has to be compartmented so that fire in one flat does not spread into another or into the shared circulation space. On a typical converted house this means fire-rated floors, walls and doors between units, and either a protected common stairway shared by the flats or separate final exits for each one, depending on the layout.
Where flats sit above ground floor level, escape routes and fire doors are designed together with the sound insulation upgrade, since the same floor and wall build-ups often need to satisfy both requirements at once.
| Conversion | Typical scope | Route | Fee from |
|---|---|---|---|
| House to two self-contained flats | Vertical split, separate or shared entrance | Full planning plus building regulations | £1,600 |
| House to three or more flats | Multiple units, fire strategy required | Full planning plus building regs plus structural | £2,400 |
| Flat conversion with a side or rear extension | Additional floor area added to create compliant units | Full planning plus structural calculations | £2,800 |

Flat Conversion Drawings in Upminster RM14 — FAQs
Do I need planning permission to convert a house into flats?+
How much do flat conversion drawings cost in London?+
What sound insulation is required between flats?+
Does each flat need a separate fire escape?+
What is the minimum size for a flat in London?+
Do I need planning permission for an extension in Havering?+
How does green-belt land affect my Havering project?+
Can I build a bigger extension because Havering plots are larger?+
How long does Havering Council take to decide?+
How much do planning drawings cost in Havering?+
Get your free Upminster planning assessment
Tell us your Upminster (RM14) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.