Change of Use Drawings in Forest Hill SE23
Fixed-fee, MCIAT-chartered change of use 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.
Change of Use Drawings for Forest Hill (SE23) homes: the package and the process
A change of use application is decided on what the building is, what it becomes, and what that changes. The drawings show the existing use class layout and the proposed one at the same scale, with a floor area schedule for each so the officer can see exactly what is moving between uses.
The supporting drawings usually matter as much as the plans. Access, parking, servicing arrangements, refuse storage and any external alteration all get drawn, because the objections to a change of use are rarely about the internal layout — they are about what the new use does to the street.
The building's form limits what it can honestly become. A ground-floor unit with its own frontage converts to residential more readily than upper floors reached through a shared entrance, and a deep plan with windows on one elevation only will struggle to give a habitable room adequate light whatever the policy position.
What counts as a material change of use?
Not every change in how a building is used needs planning permission — only a 'material' change, one significant enough to affect the character of the use of the land. Converting a single dwellinghouse into two or more flats is always material. Adding paying lodgers within a single household usually is not, until the household tips over into a small House in Multiple Occupation. We assess whether your proposed change crosses that threshold before recommending a route.
The Use Classes Order: C3, C4, E and sui generis
The Use Classes Order groups uses so planners, and permitted development rules, can treat similar activities consistently.
C3 — Dwellinghouses
The class covering a single household living as a single unit, including up to two people living together as a single household who are not related. Most family homes and self-contained flats fall here.
C4 — Houses in multiple occupation (small)
Covers a shared house or flat occupied by three to six unrelated people sharing basic amenities such as a kitchen or bathroom. Moving from C3 to C4 is a change of use, though it is often permitted development unless your borough has removed that right.
Class E — Commercial, business and service
A wide class combining shops, offices, gyms, cafes and other business uses that can change between each other without planning permission, but changing from Class E to residential use is a material change requiring the prior-approval or full planning route.
Sui generis
Uses that do not fit any class, including large HMOs of seven or more unrelated occupants, betting shops and drinking establishments. A change of use to or from a sui generis use normally needs planning permission.
Do I need full planning permission or can I use prior approval?
Some changes of use are permitted development subject to a prior-approval application rather than full planning permission — the best-known example is Class MA, which allows certain Class E commercial premises to become residential (C3) subject to the council assessing specific matters such as flooding, contamination and noise, without a full application. Other changes, including most conversions of a house into self-contained flats, fall outside any prior-approval route and need full householder or full planning permission. We identify which route applies to your building before drawing anything.
| Route | When it applies | Typical package | Fee from |
|---|---|---|---|
| Prior approval (Class MA) | Class E commercial to residential, meeting the criteria | Prior-approval drawings and statement | £1,200 |
| Full planning permission | Conversion into flats, HMO or use outside prior approval | Planning + building regs | £1,600–£2,400 |
| No application needed | Use falls within an existing permitted class change | Drawings for record purposes only | £450 |
Change of Use Drawings in Forest Hill SE23 — FAQs
How much do change of use drawings cost in London?+
What is the difference between a material change of use and general permitted development?+
How long does a change of use application take to be decided?+
Do I need an architect for a change of use application?+
Will converting my house into flats need building regulations approval too?+
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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