Mansard Loft Conversion Drawings in Hillingdon UB10
Fixed-fee, MCIAT-chartered mansard loft conversion drawings for Hillingdon (UB10) homeowners — London Borough of Hillingdon validation and local constraints handled from the start.
UB10 spans two distinct worlds: the historic village cores of Ickenham and Hillingdon Village, and the large belt of 1930s suburban semis and detached houses around them where most rear and loft projects happen. On the suburban stock the design conversation is about matching established roofline and frontage patterns, which Hillingdon's guidance sets out clearly.
Inside either village conservation area the emphasis shifts to protecting period character around St Giles and St John the Baptist churches, so materials, rooflines and boundary treatments face tighter control. Because the two conservation-area boundaries are compact, we confirm exactly where a UB10 property falls before choosing a permitted-development or full-application route.
Planning in Hillingdon (UB10): what to know before you apply
Most UB10 householder work sits on interwar suburban housing outside the conservation areas, where Hillingdon has well-established expectations for rear depth, side returns and dormers. The Ickenham Village and Hillingdon Village conservation areas are the exceptions — there, heritage-led design and usually a full application are the right approach.
Typical Hillingdon housing stock
Two protected village centres — Ickenham around St Giles Church and Hillingdon Village around St John the Baptist — of period cottages and Victorian houses, ringed by the substantial 1930s semi-detached and detached suburban stock that makes up most of the wider UB10 postcode.
Streets we regularly draw for in Hillingdon
Swakeleys Road · Austin's Lane · Royal Lane · Vine Lane
Mansard Loft Conversion Drawings for Hillingdon (UB10) homes: the package and the process
Every mansard loft conversion drawings we prepare for an Hillingdon property is drawn to London Borough of Hillingdon’s validation standards and tuned to the UB10 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.
A mansard loft conversion replaces the existing rear roof slope with a new, steeply pitched structure that runs almost to the vertical, set behind a shallow flat section at the ridge. It is the most involved of the three main loft types because it is effectively a new roof, not an addition to the old one — but it also delivers the most usable floor area and headroom, and it is the type most London terraces were designed to carry in the first place.
DrawingsDirect draws mansards for period terraces across every London borough. Because a mansard alters the whole roof form, we treat the planning application as the main event — matching slate or tile colour, window rhythm and eaves detailing to the host building and its neighbours — while coordinating the structural design, Party Wall Act notices and building regulations drawings in parallel so nothing holds up the build once consent is granted.
What is a mansard loft conversion?
A mansard replaces the rear roof slope — or, less commonly, the front and rear slopes together — with a new near-vertical wall rising from the party walls to a shallow flat roof at the ridge, with small dormer windows set into it. Unlike a dormer, which sits within the existing roof, a mansard changes the shape of the roof itself, which is why it is usually reserved for terraces where the extra headroom and floor area are worth the more involved planning and construction process. Because the new wall runs almost the full width of the house between the party walls, a mansard typically delivers noticeably more usable floor area than a single dormer of any kind, which is why it remains the preferred option on period terraces where every square metre of loft counts.
Does a mansard loft conversion need planning permission in London?
Yes, almost always. Permitted development rights for roof alterations are volume- and shape-limited, and a mansard goes well beyond what those limits allow because it materially alters the roof's profile rather than adding to it. Every mansard we draw is prepared as a full householder planning application, with a design and access statement where the borough requires one, so the council can properly assess the change to the roofline and its impact on neighbours and the street scene.
| Package | Scope | Planning route | Fee from |
|---|---|---|---|
| Rear mansard, planning only | Design, planning drawings and supporting statement | Householder planning | £1,600 |
| Rear mansard, planning and building regs | Planning drawings plus structural and Part L detailing | Householder planning | £2,200 |
| Front and rear mansard | Full roof rebuild on both slopes, with structural | Householder planning | £2,400 |
Mansard Loft Conversion Drawings in Hillingdon UB10 — FAQs
How much do mansard loft conversion drawings cost in London?+
Can a mansard ever be permitted development?+
How long do mansard drawings take?+
Will a mansard need scaffolding and affect the whole roof?+
Do you handle the party wall process as well as the drawings?+
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?+
How much do planning drawings cost in Hillingdon?+
Get your free Hillingdon planning assessment
Tell us your Hillingdon (UB10) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.