Converting a house into self-contained flats normally needs both planning permission and building regulations approval. Each new flat has to meet minimum space standards, and the building has to be separated for fire and sound. We prepare the drawings for both applications and check the council's policies before the design is fixed.
Yes, in almost every case. Subdividing a single house into two or more self-contained flats is a material change of use, so it is not permitted development. The council will assess the size and quality of the new flats, amenity space, refuse and cycle storage, parking, and the effect on the neighbours.
Some London boroughs protect family-sized houses and only allow conversions above a certain original floor area, or require at least one family-sized unit in the scheme. We check these policies against your property before drawing a layout.
London applications are assessed against the London Plan, which adopts the Nationally Described Space Standard. As a guide, a one-bedroom flat for two people needs at least 50 m² of internal floor area on one level, and a two-bedroom flat for four people needs at least 70 m². Bedrooms also have minimum sizes and widths, and there are minimum floor-to-ceiling heights.
Getting the layout right at the start is the difference between a scheme that works and one that is refused. We test several layouts against the standards before we recommend one.
Converting a house into flats is a material change of use under the Building Regulations. The key requirements are fire separation between the flats and a protected escape route (Approved Document B), sound insulation between the flats (Approved Document E), and energy efficiency, ventilation and drainage for each new unit.
These requirements often decide where walls, stairs and services can go, so we design with them in mind from the planning stage rather than redrawing later.
For planning, we prepare existing and proposed floor plans, elevations and sections, a site and location plan, and any supporting statements the council asks for. For building regulations, we prepare a detailed drawing package with construction details, fire and sound specifications and structural information, with a structural engineer arranged where calculations are needed.
We can also help with the next stages, including our design and build service and project management.
Sources: Nationally Described Space Standard; GOV.UK: Approved Documents (Part B fire safety, Part E sound and Part L energy).
Potentially. Converting a house into separate flats will normally require planning permission and must meet local requirements on space standards, amenity, parking, refuse, cycle storage and other planning considerations. Building regulations approval will also usually be required.
Yes. Creating new flats is a material change of use, so the work must meet the Building Regulations, especially for fire safety and sound insulation between the flats.
Planning drawings usually take around 14 days after the site survey, and building regulations drawings around 14 days. We confirm the timescale for your project when we quote.
Yes. We can carry out an initial assessment covering the council's planning policies, planning history, local restrictions and similar applications in the area. Planning permission can never be guaranteed, as the final decision is made by the local planning authority.
Send the address, the current layout and how many flats you have in mind.
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Each area page carries the local planning authority, conservation-area position, postcode districts and typical housing stock for that address.
