
Change of Use Drawings in Harefield UB9
Fixed-fee, MCIAT-chartered change of use drawings for Harefield (UB9) homeowners — London Borough of Hillingdon validation and local constraints handled from the start.
Harefield (UB9) is one of Hillingdon's most rural neighbourhoods — a historic village core wrapped in Green Belt on the northern edge of the borough — and that setting, rather than a standard suburban street pattern, drives how extensions are assessed here. Schemes that keep additions subordinate and in-keeping with the village grain are the ones that move smoothly through the council.
The Harefield Village conservation area protects the scattered building layout, the green and the countryside views, so rooflines, materials and the openness between buildings are treated as part of the heritage. We check both the conservation-area boundary and the surrounding Green Belt designation before advising on what a UB9 plot can realistically support.


Planning in Harefield (UB9): what to know before you apply
UB9 combines two of the strongest planning controls in the borough — a rural conservation area and widespread Green Belt — so extension scale and siting matter more here than almost anywhere else in Hillingdon. We design Harefield schemes to read as modest, subordinate additions that respect the village setting, which is what the council looks for.
Typical Harefield housing stock
A dispersed village centre of cottages and period houses around the green and St Mary's Church, mixing medieval and post-medieval buildings with Victorian and 20th-century infill, set against open countryside on the borough's northern edge.
Streets we regularly draw for in Harefield
High Street · Church Hill · Park Lane · Rickmansworth Road
Change of Use Drawings for Harefield (UB9) homes: the package and the process
Every change of use drawings we prepare for an Harefield property is drawn to London Borough of Hillingdon’s validation standards and tuned to the UB9 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.
| 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 Harefield UB9 — 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 loft conversion in Hillingdon?+
How does the Colne Valley green belt affect my Hillingdon project?+
Does proximity to Heathrow affect my plans?+
How long does Hillingdon Council take to decide?+
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