Loft conversions and roof space extensions in Hammersmith and Fulham
Loft Conversion in Hammersmith and Fulham, London
Lian Construction carries out full loft conversions across London, across all of London, from inner boroughs out to South West London and the wider capital. We handle the whole project as one sequence: structural floor strengthening, staircase installation, dormer, hip-to-gable or mansard roof alterations, insulation, fire escape compliance, and electrics and heating extended into the new room, rather than leaving you to coordinate a builder, roofer and building control application separately. Work ranges from a single rooflight conversion adding a home office above a Victorian terrace, through to a full mansard conversion creating two new bedrooms and an ensuite. We survey the roof, advise honestly on what the space can realistically achieve, and manage building regulations and any party wall matters alongside the build itself.
Hammersmith and Fulham overview
Loft Conversion in Hammersmith and Fulham
West London borough with high-value period conversions where quality finishing work — tiling, plastering, decorating — matters most. Hammersmith and Fulham falls well within the West London ground Lian Construction covers on a regular basis. For loft conversion work in Hammersmith and Fulham, that local knowledge means fewer surprises once work is on site and a team that already understands the borough's typical property stock.
Hammersmith and Fulham's housing stock is dominated by the kind of period property found across much of inner and West London: Victorian and Edwardian terraces and villas, many of which have been split into flats over the decades, alongside mansion blocks and some purpose-built conversions from the early to mid-20th century. A significant share of the borough's homes are conversions rather than single-family houses, which is typical of high-value West London areas where large period houses have been reworked into two, three or more flats to meet demand. This conversion history means a lot of the existing stock carries older wall and floor build-ups, original plasterwork in varying condition, and layouts that have been altered more than once. As with other West London boroughs, there's also a mix of ex-local authority blocks and post-war infill alongside the period stock. Because so much of the housing is period conversion rather than new-build, quality of finish tends to matter more here than in areas with a higher proportion of modern construction, since old walls, ceilings and floors need careful preparation before tiling, plastering or decorating will look right and last.
In a borough where so much of the property is high-value period conversion, the finishing trades carry more weight than they might elsewhere. A flat carved out of a Victorian terrace lives or dies on how well the plaster, tiling and decorating are done, since buyers and tenants at this end of the market notice uneven walls, poor tile lines or rough paintwork more readily than they would in a standard new-build. That creates steady demand for contractors who can do finishing work properly rather than just quickly, particularly on bathroom and kitchen refits where tiling quality is hard to hide. It also means homeowners and landlords doing up a conversion flat are often better served focusing budget on getting the finishing right rather than cutting corners to save on the last stage of a project. For landlords specifically, a well-finished conversion tends to let faster and at a better rent in this kind of market, so the extra cost of proper plastering and tiling work is usually recovered over time. Given the age and variability of the underlying building fabric, it's also worth budgeting some contingency for making good old walls and floors before the visible finishing work even starts.
Given how much of Hammersmith and Fulham's housing stock is period conversion, it's worth being aware that conservation area and listed building rules are common across this type of West London property, as they are in many inner London boroughs. Converting or altering a period house can trigger planning or listed building consent requirements depending on the specific property and area, particularly for external changes, window replacements or work affecting original features. Internal finishing work like plastering, tiling and decorating is generally more straightforward from a planning perspective, but if it's part of a wider conversion or alteration project it's sensible to check the property's status with the council before starting. As with any older building, it's also worth confirming what internal fabric might be original or protected before stripping back walls, since this can affect both the approach and the cost of the finishing work.
Typical loft conversion prices in London
Item
Typical range
Rooflight/Velux conversion
£28,000–£45,000
Dormer conversion (single rear dormer)
£45,000–£65,000
Mansard conversion
£70,000–£95,000+
General London market guidance, not a fixed quote — actual pricing depends on a site survey. Full breakdown: cost guide.
How long a loft conversion takes and what disruption to expect
Programme length depends heavily on the type of conversion and how much of the roof structure is changing. A straightforward rooflight conversion, without any alteration to the roof shape, typically takes around four to six weeks from scaffold going up to final handover. A dormer conversion, the most common type on London terraces, usually takes six to ten weeks, since it involves more roof alteration, a larger structural floor, and often an ensuite. A hip-to-gable or mansard conversion takes longer again, often ten to fourteen weeks or more, reflecting the scale of roof rebuild involved and the additional structural and finishing work that comes with a larger new floor area. Before any of that build time starts, though, there's usually a lead-in period for the planning route, whether that's confirming permitted development status or waiting on a full planning decision, and for party wall notices where they apply, since a notice period of two months has to run before affected work can begin, and this lead-in time needs building into the overall timeline from the outset rather than assumed to run alongside the build itself. Once building work starts, scaffolding goes up first, followed by opening up the roof structure, which is sequenced carefully to keep the property weathertight at the end of each working day using temporary covering if a section is left open overnight. The most disruptive stage for the rest of the house is usually cutting the staircase opening into the existing floor, since it affects the room directly below and briefly opens up a structural gap that needs supporting properly until the new stairs are in. Most households can continue living in the property throughout a loft conversion, since the work is largely contained to the roof space and the staircase area, though noise and dust are unavoidable during the structural stages, and access to the room below the new staircase opening is more restricted while that work is ongoing. Weather affects the roof-opening stages in particular, so we plan those for the most settled part of the forecast available and build some contingency into the programme rather than promising a fixed date that depends entirely on the weather cooperating.
What drives the cost of a loft conversion, and specification tiers
Loft conversion cost varies more than most home improvement projects, because the type of conversion, the structural work involved and the specification chosen all move the price independently of each other. Conversion type is the first major variable: a rooflight conversion is the cheapest option since it avoids altering the roof structure, a dormer sits in the middle, and a hip-to-gable or mansard conversion costs considerably more because both involve rebuilding a significant section of the roof rather than adding to it. Structural work is the next big driver. Existing loft joists are almost never sized for a habitable room, since they're designed to carry storage loads rather than furniture and people, so most conversions need the floor strengthened, either by adding new joists alongside the existing ones or introducing steel beams to carry the new floor loads, and the staircase opening cut into the floor below removes structural support that has to be replaced with trimmer joists around the new opening. The staircase itself adds cost beyond the opening: a straight flight is simpler and cheaper than a winding or space-saver staircase squeezed into a tight footprint, and losing some floor area on the level below to accommodate it is unavoidable in most houses. Ensuite bathrooms add plumbing runs, a waste fall back to the stack and additional electrics on top of the base conversion cost, and where the roof covering needs matching to the existing tiles or slates for planning or appearance reasons, sourcing a matching material can cost more than a standard replacement tile. As a broad guide to specification tiers, a basic rooflight conversion finished simply for storage, a home office or a single bedroom without an ensuite sits at the more affordable end of the range; a mid-tier rear dormer conversion with a double bedroom and a small ensuite is the most common specification we quote for London terraces; and a higher-tier full-width dormer, hip-to-gable or mansard conversion creating two bedrooms and a bathroom sits considerably higher again, reflecting the greater structural work and floor area involved. We break quotes down by structural work, roof alterations, staircase, insulation, and any plumbing and electrical work, rather than a single lump figure, so it's clear where a specification change actually moves the price.
Dormer, hip-to-gable and mansard loft conversionsStructural floor strengthening and staircase installationBuilding regulations and fire escape compliance handledRegular coverage of Hammersmith and Fulham and the wider West London area
Signs to look for
Do you need loft conversion in Hammersmith and Fulham?
The roof covering is due for renewal anyway, which makes it sensible to combine re-covering with a conversion rather than doing both separately.
The loft is currently used only for storage while someone in the household genuinely needs a bedroom, office or playroom instead.
The property is a Victorian or Edwardian terrace with a straightforward roof shape well suited to a rear dormer conversion.
The house is semi-detached or detached with a hipped roof end that could be extended into usable space through a hip-to-gable conversion.
How the work is handled in Hammersmith and Fulham
Step 1Survey the loft and advise on conversion type
Step 2Handle building regulations and any party wall notices
Step 3Strengthen the floor, alter the roof and install the staircase
Step 4Insulate, fit out and sign off before handover
Questions
Loft Conversion questions in Hammersmith and Fulham
How quickly can Lian start loft conversion work in Hammersmith and Fulham?
Hammersmith and Fulham is part of our regular West London coverage, so once we've surveyed the property we can usually confirm a start date quickly. Send the address and scope and we'll arrange the next step.
Do you cover all of Hammersmith and Fulham?
Yes. Hammersmith and Fulham falls within the area Lian Construction serves across Greater London.
How long does a typical bathroom retiling job take in a period flat?
It depends on the state of the walls underneath, but as a rough guide a standard bathroom retile in an older property, including stripping old tiles and making good the plaster, usually takes a week or so. Uneven or damp walls, which are fairly common in period conversions, can add extra days for repair work before any tiling starts. We'd normally confirm timescales once we've seen the actual condition of the walls.
What are the permitted development volume limits for a loft conversion?
Under the current permitted development rules, a terraced house can typically add up to 40 cubic metres of additional roof space, and a detached or semi-detached house up to 50 cubic metres, alongside conditions on materials, no verandas or balconies, set-back from the original eaves, and obscure-glazed side windows. Previous extensions on the same property can reduce how much of that allowance is left, and an Article 4 direction can remove the right entirely in some streets or conservation areas. These figures are a general guide rather than a guarantee for your specific property, so we'd always recommend checking with the council or getting a lawful development certificate before relying on them.
Will a loft conversion need a party wall agreement with my neighbour?
On most terraced and semi-detached properties, yes, at least in part, since the roof structure, chimney stacks or new structural beams supporting the strengthened floor usually bear onto or near the shared party wall. We identify at survey stage where the Party Wall etc. Act 1996 is likely to apply and build the notice periods into the programme, but agreeing and issuing the party wall award itself is a separate process carried out by party wall surveyors appointed by each owner, not something we do as the builder. Starting this process early matters, since it typically takes several weeks to resolve and can hold up the start of structural work if left too late.
Which type of loft conversion suits my house?
It depends on the roof shape, existing headroom and how much space you need. A rooflight conversion suits a loft that already has reasonable headroom and keeps the roof structure unchanged, a dormer conversion is the most common option on London terraces and adds both headroom and floor area, a hip-to-gable conversion suits semi-detached or detached houses with a hipped roof end, and a mansard conversion delivers the most space but involves the biggest rebuild and most often needs full planning permission. We'll survey the loft and talk through which options are genuinely realistic for your roof rather than defaulting to the most expensive one.
Talk to Lian Construction about Hammersmith and Fulham
Send the site address in Hammersmith and Fulham, photos if available, and the loft conversion work you need. We can review the scope and arrange the next step.