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

Feltham · TW13 · Hounslow

Loft Conversion Drawings in Feltham TW13

Fixed-fee, MCIAT-chartered 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

What TW13 is actually built of

Measured from 396 classified residential buildings in TW13, not from a description of the area.

Feltham TW13 housing mix

Residential building form across the TW13 postcode district, from 396 classified buildings.

Attached on more than one side	41%
Attached on one side	54%
Detached	5%
Median building footprint	54 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	1.56
Buildings classified	396

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 2026-09-22.

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

A loft stands or falls on the section drawing. It has to prove usable head height along the length of the room, a staircase that meets the going and headroom rules without eating the landing below, floor joists sized for a habitable load rather than storage, and a means of escape that Building Control will accept — usually a protected stair, sometimes an escape window.

The same section does the planning work too, showing roof volume, ridge height and how the new form sits against the existing roof. Where the conversion relies on permitted development we set the volume out on the drawing as a calculation, so the position is evidenced rather than asserted.

Roof shape decides which conversion is even possible. A hipped roof has to become a gable before it offers full-width space; a shallow pitch may not deliver head height at any cost; and a terrace with a rear outrigger opens up an L-shaped option a detached house has no use for.

Do I need planning permission for a loft conversion in London?

Many loft conversions are permitted development, but volume limits (40m³ for terraced homes, 50m³ for detached and semi-detached), materials and the presence of a conservation area or Article 4 direction can change that. We assess your roof and borough and recommend the fastest lawful route — often a Lawful Development Certificate rather than a full planning application. A certificate is worth having even when the work is clearly permitted: it gives your buyer's solicitor and your building-control surveyor documentary proof the loft is lawful, which matters when you sell.

Which loft conversion type suits your roof?

The best conversion depends on your roof shape and the headroom it offers.

Dormer

A box dormer adds headroom and floor area at the rear and is the most common London loft — frequently permitted development.

Mansard

A mansard rebuilds the rear (or front and rear) roof slope for maximum space, common in conservation areas but usually needing planning permission.

Hip-to-gable

Extends a hipped roof to a vertical gable, ideal for semi-detached and end-of-terrace homes.

Velux / rooflight

The simplest option — rooflights within the existing roofline, almost always permitted development.

What building regulations apply to a loft conversion?

Loft conversions must meet fire escape, structural and insulation standards — a protected stairway, adequate floor joists and beams, and often a means of escape window. A loft that adds a third storey to a two-storey house triggers stricter fire-separation rules, including fire doors to habitable rooms off the new stairway. We coordinate the structural calculations with the drawings so the build proceeds without delays.

London loft conversion types, routes and typical fees
Loft type	Best for	Usual route	Fee from
Velux / rooflight	Roofs with existing headroom	Permitted development / LDC	£695
Dormer	Rear headroom + floor area	Permitted development / LDC	£695
Hip-to-gable	Semi and end-of-terrace roofs	Permitted development or planning	£745
Mansard	Maximum space, conservation areas	Full planning application	£845

Example loft conversion drawings sheet showing the existing and proposed arrangement at scale, as we draw it for Feltham (TW13) properties — Example sheet showing how we draw loft conversion drawings to London Borough of Hounslow's validation standards for Feltham (TW13) properties.

Also in Feltham TW13

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings House Extension Drawings Loft Conversion Drawings across London

FAQ

Loft Conversion Drawings in Feltham TW13 — FAQs

How much do loft conversion drawings cost in London?+

Drawing packages typically start around £695 for a permitted development loft and rise for mansards and full planning applications. Structural calculations for the steels are a separate fee from £745 unless you choose the all-inclusive package. We quote a fixed fee upfront.

Will my loft need a fire escape window?+

Most loft conversions require a means of escape and a protected stairway under building regulations. We design these in from the start.

Is a dormer loft permitted development?+

Often yes, within the volume limits and outside conservation areas — but we always check your specific property and borough first, free.

Can I convert my loft if I live in a conservation area?+

Usually yes, but conservation areas and Article 4 directions often remove permitted development for rear dormers, so the work needs a full planning application and a roof-form the council will accept — commonly a mansard or discreet rear dormer. We check your borough's designation before recommending a route.

Do you provide the structural calculations for the steels?+

Yes, through a named, insured engineer, as a separate service from £745. The calculations cover the floor beams and any ridge or purlin steels, and we draw them onto your loft set; our all-inclusive package, £1,845–£3,145, includes them. If you already have an engineer, we work from their figures.

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. Roof enlargements such as dormers, side extensions, rear extensions over one storey and cladding are not permitted development in a conservation area, so we design to the Arts-and-Crafts character here 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?+

In Hounslow, a valid application sets eight weeks running from the day after, and only written agreement lengthens them. Bedford Park, conservation and riverside cases can involve additional consultation, so we follow the checklist.

How much do planning drawings cost in Hounslow?+

We agree a fixed fee before starting, taken from our published price list, 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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