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Free 2026 London Planning ReportChange of Use Drawings in Forest Hill SE23

Loft conversion with skylights in a Victorian villa in Forest Hill SE23, London Borough of Lewisham
Forest Hill · SE23 · Lewisham

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.

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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.

Loft conversion with skylights in a Victorian villa in Forest Hill SE23, London Borough of Lewisham
Isometric illustration of a Forest Hill SE23 home change of use drawings design
Proposed floor plan
Forest Hill SE23

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

Change of Use Drawings for Forest Hill (SE23) homes: the package and the process

Every change of use drawings we prepare for an Forest Hill property is drawn to London Borough of Lewisham’s validation standards and tuned to the SE23 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.

A change of use — converting a house into flats, a shop into a flat, or adding a lodger room that tips a home into a small HMO — is governed by the Use Classes Order, which groups land and buildings into classes such as C3 (dwellinghouses), C4 (small shared houses) and E (commercial, business and service uses), plus a handful of uses that sit outside any class, known as sui generis. Whether you need a full planning application, a prior-approval notification, or nothing at all depends on which classes the 'before' and 'after' uses fall into, and whether your permitted development rights have been restricted locally.

DrawingsDirect prepares the drawings and supporting information a London borough needs to assess a change of use — existing and proposed floor plans, a use and amenity statement, and where relevant a parking and refuse strategy — and advises which route applies before you commit to an application. We cover conversions into flats, commercial-to-residential schemes under the prior-approval Class MA route, and other changes of use across all 33 London boroughs.

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.

Change of use routes for a London property
RouteWhen it appliesTypical packageFee from
Prior approval (Class MA)Class E commercial to residential, meeting the criteriaPrior-approval drawings and statement£1,200
Full planning permissionConversion into flats, HMO or use outside prior approvalPlanning + building regs£1,600–£2,400
No application neededUse falls within an existing permitted class changeDrawings for record purposes only£450
FAQ

Change of Use Drawings in Forest Hill SE23 — FAQs

How much do change of use drawings cost in London?+
Change of use packages typically start from £1,200, depending on whether the route is prior approval or full planning permission and how many units are involved. We agree a fixed fee before drawing begins.
What is the difference between a material change of use and general permitted development?+
A material change of use concerns what a building or piece of land is used for, while permitted development more broadly also covers physical building work. Some material changes of use are themselves permitted development, such as certain Class E to residential conversions under Class MA, but many, including converting a house into flats, are not.
How long does a change of use application take to be decided?+
A prior-approval application under Class MA is typically decided within 56 days; a full planning application follows the usual eight-week statutory period for most schemes. We prepare a complete package to avoid delays caused by missing information.
Do I need an architect for a change of use application?+
No. As an MCIAT-chartered architectural technologist practice, we prepare the same council-accepted drawings and statements an architect would, typically at a lower fee, and can submit via the Planning Portal on your behalf.
Will converting my house into flats need building regulations approval too?+
Yes. Converting a house into self-contained flats almost always triggers building regulations, covering fire separation, sound insulation between units and means of escape, in addition to any planning permission needed for the change of use.
Do I need planning permission for a side-return extension in Lewisham?+
On the Victorian and Edwardian terraces of Brockley, Forest Hill and Hither Green a single-storey side-return or rear extension can fall within permitted development, so a full application isn't always needed. Conservation areas such as Blackheath, Brockley and Telegraph Hill restrict this. We check your street's designation first and can confirm permitted development with a Lawful Development Certificate where it qualifies.
What does Lewisham's borough-wide HMO Article 4 direction affect?+
Lewisham applies a borough-wide Article 4 direction removing permitted development rights for change of use to an HMO (C3 to C4), so a conversion to a house in multiple occupation needs a full application anywhere in the borough. It doesn't affect a standard family extension or loft, but we confirm whether it applies to your intended use before advising on a route.
Can I convert the loft on my Lewisham terrace?+
Usually, yes. The terraces of Brockley, Forest Hill and Hither Green suit hip-to-gable and dormer loft conversions, which frequently qualify as permitted development within the volume limits. Outside the conservation areas this is often the quickest route. We confirm eligibility against those limits and any designation, then produce the planning and building-regulations drawings.
How long does Lewisham Council take to decide?+
Lewisham determines most householder applications within the statutory eight-week period once validated; conservation cases can attract additional consultation. The dense terraced streets are party-wall-sensitive, so the commonest delay is a drawing query — we prepare submissions to the council's validation checklist to keep them moving.
How much do planning drawings cost in Lewisham?+
We agree a fixed fee before starting, usually around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Lewisham approves. A side-return, a loft and a conservation-area scheme differ in complexity, so we quote once we understand your street and project rather than charging by the hour.
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