HMO Conversion Drawings in Forest Hill SE23
Fixed-fee, MCIAT-chartered hmo conversion drawings for Forest Hill (SE23) homeowners — London Borough of Lewisham validation and local constraints handled from the start.
Forest Hill (SE23) in Lewisham is a hilly Victorian suburb of substantial villas and terraces around the Horniman Museum and gardens. The steep topography and the Forest Hill conservation area together shape what works for extensions and loft conversions here.
Within the conservation area an Article 4(3) direction removes specified permitted development rights, so many changes that would be permitted elsewhere need a full application designed to the area's Victorian character; the steep plots add overlooking and level-change considerations. Lewisham's small-HMO Article 4 direction is a further control on conversions.
Planning in Forest Hill (SE23): what to know before you apply
The Forest Hill conservation area carries an Article 4(3) direction removing specified householder permitted development rights, so loft and extension projects within it generally need a full planning application rather than relying on permitted development. The steep hillside plots and mature trees around the Horniman add design and TPO considerations, and Lewisham's small-HMO Article 4 direction restricts new conversions.
Typical Forest Hill housing stock
Substantial Victorian villas and terraces climbing the hills around the Horniman Museum, with later Edwardian and interwar houses on the higher ground toward Honor Oak.
Streets we regularly draw for in Forest Hill
London Road · Dartmouth Road · Honor Oak Road · Devonshire Road
What SE23 is actually built of
Measured from 377 classified residential buildings in SE23, not from a description of the area.
Forest Hill SE23 housing mix
Residential building form across the SE23 postcode district, from 377 classified buildings.
| Attached on more than one side | 50% |
|---|---|
| Attached on one side | 39% |
| Detached | 11% |
| Median building footprint | 67 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.8 |
| Buildings classified | 377 |
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.
HMO Conversion Drawings for Forest Hill (SE23) homes: the package and the process
An HMO scheme is drawn against a schedule. Every bedroom is dimensioned with its usable floor area stated, shared kitchen and bathroom provision is counted against the number of occupants, and the layout has to hold up against the space standards the licensing team applies.
The fire strategy is drawn, not described: protected escape route, fire doors and their ratings, alarm coverage by room, and compartmentation between floors. Licensing and building control assess the same drawing set from different angles, so it has to satisfy both without contradiction.
Room count is a function of the existing plan. A large semi or detached house with generous rooms can meet the space standards without subdivision, while a narrow terrace usually cannot reach the same occupancy without creating rooms that fall below the minimum floor area.
C4 small HMO or sui generis large HMO — which applies to your property?
The distinction matters because it decides which rules apply. A small HMO housing three to six unrelated sharers who share amenities is Class C4. A large HMO of seven or more occupants is sui generis and always needs planning permission, since sui generis uses sit outside the permitted development system entirely. The line also shifts with occupancy — a property let to six sharers today can tip into sui generis territory the moment a seventh tenancy is signed, which changes the planning position even though nothing about the building itself has changed. We assess your proposed occupancy and layout against both definitions before drawing, so the application matches how the property will actually be let.
Do I need planning permission for an HMO conversion in London?
Converting a family home (C3) into a small HMO (C4) is technically permitted development under national rules, but a large number of London boroughs have made an Article 4 direction that removes this right across all or part of the borough — meaning a full planning application is required even for a small, compliant HMO. Article 4 directions vary street by street in some boroughs, so two similar houses a few doors apart can sit on opposite sides of the line. Any large HMO (sui generis) needs planning permission everywhere, regardless of Article 4. We check your specific address against the relevant borough's Article 4 direction before recommending a route, since guessing wrong wastes both time and application fees.
Mandatory and additional HMO licensing — what's required?
Most HMOs need a licence from the council, separate from any planning permission. A licence application typically has to demonstrate that the property meets fire safety, amenity and space standards, that gas and electrical installations are safety-certified, and that the landlord or managing agent is a fit and proper person to hold it.
Mandatory licensing
Applies to any HMO of five or more occupants forming two or more households, regardless of the number of storeys — a national requirement in every London borough.
Additional licensing
Many boroughs extend licensing to smaller HMOs, typically three or four occupants, across all or part of their area. We check the current scheme for your borough before you apply, since schemes and boundaries change.
| Factor | C4 small HMO (3–6 sharers) | Sui generis large HMO (7+) |
|---|---|---|
| Use class | C4 | Sui generis |
| Planning permission | Often needed due to Article 4 directions in most boroughs | Always needed |
| Licensing | Mandatory if 5+ occupants; additional licensing in many boroughs | Mandatory |
| Typical drawing package | From £1,400 | Full planning + building regs, from £2,200 |
HMO Conversion Drawings in Forest Hill SE23 — FAQs
How much do HMO conversion drawings cost in London?+
Is HMO conversion permitted development in London?+
Do I need a licence as well as planning permission?+
Do I need an architect for an HMO conversion?+
How long do HMO conversion drawings take?+
Do I need planning permission for a side-return extension in Lewisham?+
What does Lewisham's borough-wide HMO Article 4 direction affect?+
Can I convert the loft on my Lewisham terrace?+
How long does Lewisham Council take to decide?+
How much do planning drawings cost in Lewisham?+
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