Single-storey rear extension on a 1930s semi in Feltham TW13, planning drawings for London Borough of Hounslow approval

Feltham · TW13 · Hounslow

Dormer Loft Conversion Drawings in Feltham TW13

Fixed-fee, MCIAT-chartered dormer loft conversion drawings for Feltham (TW13) homeowners — London Borough of Hounslow validation and local constraints handled from the start.

Feltham is an outer-west Hounslow suburb built largely between the wars and in the post-war decades, so the bulk of our work here is family-driven: single-storey rear extensions, side-return infills and loft conversions on 1930s semis and estate housing. Wide plots on roads such as Southern Avenue and Ashmead Road usually leave comfortable room to extend under permitted development while keeping the front elevation intact.

Where a plot sits near the St Dunstan's or Hanworth Park conservation areas, or on the lower ground close to the River Crane, we design to Hounslow Council's expectations from the outset — matching brick and roof lines, respecting the depth and height limits, and building in flood-resilient drainage detail so the application clears validation without an avoidable refusal.

Proposed floor plan

Feltham TW13

Feltham (TW13) — planning at a glance

Council: London Borough of Hounslow
Postcode district: TW13
Planning portal: View the Hounslow planning portal
Housing stock: Feltham is dominated by 1930s bay-fronted semis and post-war council-built estates, with generous rear gardens on roads like Southern Avenue and Glebelands Road. Plots are wide enough for single-storey rear extensions, side infills and hip-to-gable loft conversions without needing to touch the front elevation.
Article 4: London Borough of Hounslow does not publish its Article 4 directions to the national planning register, so permitted development rights in Feltham (TW13) can’t be confirmed from open data alone — we check the direction schedule with the council before recommending a route, as part of the fixed fee. No published householder Article 4 across Feltham's interwar and post-war estates — most rear and side extensions sit within permitted development, so the constraint is proximity to the Hanworth Park and St Dunstan's conservation areas rather than a borough-wide direction.
Conservation: Hanworth ParkSt Dunstan'sFeltham Town Centre
Sample streets: Southern Avenue · Glebelands Road · Ashmead Road · Browells Lane
Local constraints: Most of the housing stock is interwar/post-war semi-detached, so party wall agreements with immediate neighbours are the norm for rear and side worksThe St Dunstan's and Hanworth Park conservation areas tighten what is acceptable near the village core and parkland edgeFeltham Town Centre conservation area governs the busier commercial frontages rather than the residential streetsLow-lying ground near the River Crane and Longford River means some plots fall within Environment Agency flood zones and need a drainage-aware design

Planning in Feltham (TW13): what to know before you apply

There is no published householder Article 4 direction in Feltham, so most rear and loft projects proceed under permitted development. Watch the St Dunstan's, Hanworth Park and Feltham Town Centre conservation areas, and the flood constraint on plots near the River Crane, where PD rights and extension depths are more tightly read.

Typical Feltham housing stock

Feltham is dominated by 1930s bay-fronted semis and post-war council-built estates, with generous rear gardens on roads like Southern Avenue and Glebelands Road. Plots are wide enough for single-storey rear extensions, side infills and hip-to-gable loft conversions without needing to touch the front elevation.

Streets we regularly draw for in Feltham

Southern Avenue · Glebelands Road · Ashmead Road · Browells Lane

Dormer Loft Conversion Drawings for Feltham (TW13) homes: the package and the process

Every dormer loft conversion drawings we prepare for an Feltham property is drawn to London Borough of Hounslow’s validation standards and tuned to the TW13 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.

A dormer is the loft conversion most London homeowners picture first: a box-shaped or L-shaped addition built into the rear roof slope that turns a cramped loft void into a full-height bedroom or bathroom. Box dormers sit squarely on the main rear slope; L-shaped dormers link that main-roof dormer to a second one over the rear closet wing found on most Victorian and Edwardian terraces, roughly doubling the usable floor area for a similar planning risk.

DrawingsDirect draws both types for London roofs every week. Because the permitted development rules for dormers turn on volume, elevation and location as much as design, we check your eligibility for a Lawful Development Certificate before recommending a full planning application — and if your roof actually suits a hip-to-gable or mansard conversion better, we say so rather than drawing the wrong scheme.

Is a rear dormer loft conversion permitted development in London?

A single rear dormer is the loft conversion most likely to qualify as permitted development in London, provided it stays within the volume allowance — 40 cubic metres for terraced houses, 50 cubic metres for detached and semi-detached homes. The dormer must not extend beyond the highest part of the existing roof, should be set back from the eaves where practical, and is normally finished in materials that match the existing roof. Where the numbers work, we recommend a Lawful Development Certificate rather than a full planning application, because it is faster and gives you a legal record that the work was lawful.

Box dormer or L-shaped dormer — which suits a London terrace?

A box dormer is a simple flat-roofed addition set into the rear roof slope, adding headroom and floor area over the main roof void. An L-shaped dormer links that main-slope dormer to a second dormer over the rear closet wing — the small rear addition found on most Victorian and Edwardian London terraces — and is popular because it captures far more usable space over the stairwell for a similar planning risk. Both are generally assessed the same way for permitted development, but the closet-wing element of an L-shaped dormer needs its own structural support, which we detail on the drawings and coordinate with the structural calculations.

Box dormer: single flat-roofed addition on the main rear slope
L-shaped dormer: main-slope dormer combined with a closet-wing dormer
Both are typically finished in matching brick, tile-hung or render to suit the host roof

Typical dormer loft conversion drawing packages
Dormer type	Typical route	Structural scope	Fee from
Single rear box dormer	Permitted development / LDC	Standard joist and beam upgrade	£1,100
L-shaped rear dormer	Permitted development / LDC	Additional closet-wing support	£1,300
Front dormer	Householder planning	Standard joist and beam upgrade	£1,600
Dormer in a conservation area	Householder planning	Standard joist and beam upgrade	£1,600

Also in Feltham TW13

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings Loft Conversion Drawings Dormer Loft Conversion Drawings across Hounslow Dormer Loft Conversion Drawings across London

FAQ

Dormer Loft Conversion Drawings in Feltham TW13 — FAQs

How much do dormer loft conversion drawings cost in London?+

A single rear box dormer on the permitted development route typically starts around £1,100 for a full drawing set. L-shaped and front dormers cost more because of the extra structural design and, for front dormers, the planning application itself — we quote a fixed fee once we have seen your roof.

Is my dormer definitely permitted development?+

Not automatically — it depends on the volume you are adding, which elevation the dormer sits on, and whether a conservation area or Article 4 direction applies to your address. We check this free before recommending a route, and if a previous loft or roof extension has already used up part of your allowance, we factor that into the calculation too.

How long do dormer loft conversion drawings take?+

Typically around 7 days from survey to a full drawing set delivered to your online portal, whether you are going down the Lawful Development Certificate route or full planning.

Will I need an architect for a dormer loft conversion?+

No — as MCIAT-chartered architectural technologists we produce the same council-accepted drawings an architect would, typically at a lower fee, with structural calculations coordinated in-house.

What if my roof suits a different loft conversion type?+

If your roof is hipped, a hip-to-gable conversion may add more space than a dormer alone; if you are in a conservation area needing a full rebuild of the roof slope, a mansard may suit better. We assess your roof against all three before recommending one.

Do I need planning permission for an extension in Hounslow?+

It depends on the area. The interwar semis of Osterley, Hounslow and Feltham often retain permitted development rights for rear extensions and lofts, while the Chiswick terraces and Bedford Park sit within conservation areas where those rights are removed. We check your address against the designations first and can confirm permitted development with a Lawful Development Certificate.

What extra control applies in Bedford Park?+

Bedford Park is one of West London's most tightly controlled conservation areas, with detailed control over materials, rooflines, windows and front elevations. A standard permitted-development dormer or cladding change usually won't apply; instead we design to the area's Arts-and-Crafts character and prepare a full householder application with the elevations and materials the council expects.

Does Heathrow or the river affect my Hounslow project?+

They can. Toward the west of the borough, aircraft-noise considerations near Heathrow may influence habitable-room and glazing design, and along the Thames at Strand-on-the-Green and Isleworth the flood zone must be addressed. We evidence these considerations within the application where they apply so the council can validate and approve without repeated revisions.

How long does Hounslow Council take to decide?+

Hounslow determines most householder applications within the statutory eight-week period once validated; Bedford Park, conservation and riverside cases can involve additional consultation. We prepare submissions to the council's validation checklist to avoid the drawing queries that cause most delays.

How much do planning drawings cost in Hounslow?+

We agree a fixed fee before starting, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Hounslow approves. A suburban Osterley extension and a Bedford Park application differ in the evidence required, so we quote once we understand your address and project rather than by the hour.

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