Loft conversion specialists covering Washington in West Sussex and the RH20 villages along the foot of the Downs. We design and build dormer, hip-to-gable, Velux, mansard and L-shape conversions on homes of every age and size, with architectural support built into every project. Contact us for a free, no-obligation quote on your Washington loft conversion.
Thinking about a loft conversion in Washington? Apex designs and builds them across this West Sussex village, a short run up the A24 from our Worthing base. This is the RH20 village below the escarpment, not the town in Tyne and Wear. One local fact is worth having before anything else: Washington sits inside the South Downs National Park, so planning applications go to the South Downs National Park Authority rather than to Horsham District Council, which provides other local services. Neighbouring RH20 villages sit outside the Park, so the answer a friend two miles away gives you may not be the answer for your address.
That distinction changes who assesses the design and what they weigh. Inside the Park, changes to the roofline are judged against the wider downland setting as well as against the house itself, and a designated conservation area covers part of the village on top of that. In practice the lower-impact options tend to have the smoother route, and the more visible ones need a stronger design case. None of that puts a loft conversion out of reach here. It means the design is worth resolving properly before drawings are commissioned, rather than after.
What your roof can actually deliver is a separate question, and one we answer at the first visit. Ridge height, the way the roof is framed, where the chimney stacks sit and where a new staircase can land all shape the recommendation, and they vary far more from house to house than the planning position does. As local loft conversion builders we run the job as one project rather than a series of trades. Our trusted architectural partners can prepare drawings and, where one is needed, submit a planning application or Lawful Development Certificate on your behalf, and we build to current Building Regulations throughout. We start with a free, no-obligation site visit and tell you straight what is achievable. Contact us for a free quote on your Washington loft conversion.
The right loft conversion for your Washington home comes down to the shape of the roof, how much extra space you need, and how far the external roofline can change in a National Park setting. Five conversion types cover almost everything we take on here and across the wider RH20 area. Because the more visible options carry a heavier design case inside the Park, they are worth weighing against the low-impact ones early, and we will recommend the right approach for your property after the first visit.
A dormer projects outward from the existing roof slope to create standing headroom and usable floor area where the original roof closed in, and it remains the most common way to turn an unused loft into a proper room. In Washington a modest rear dormer is usually the version worth pursuing, because it sits low in views from the surrounding downland. Anything large or forward-facing attracts closer attention, and size, position and detailing all carry weight in the assessment, so the design is best settled early. The space gained differs from one property to the next.
Suited to the hipped-roof semis and detached homes among the village’s later housing, where the side of the roof slopes inwards instead of rising to a vertical wall. Rebuilding that slope up to a full gable releases the internal volume a hipped roof otherwise wastes, and it is often paired with a rear dormer where the original profile is tight. Because a gable alters the outline of the house against the Downs behind it, the case is stronger away from the most exposed frontages. Layouts depend on the individual property.
The least invasive of the five, and frequently the sensible answer in a National Park village where leaving the roof profile alone counts for a great deal. The roof stays as it is: we strengthen the structure, insulate, board the floor and fit rooflights for daylight. Planning permission is rarely required for a rooflight conversion, and conservation-style rooflights are sometimes preferred in the more sensitive positions. A listed property will still need listed building consent, which is a separate consent from planning permission.
The most transformative of the five types. A mansard rebuilds the rear, and occasionally the front, roof slope to near vertical to win the maximum floor area and headroom, and full planning permission is effectively always required. In a village inside the National Park with a conservation area over part of it, a mansard is the hardest case to make, so it is worth confirming the position with the National Park Authority and a planning consultant before committing to anything.
Suited to homes with a two-storey rear outrigger, the side return, which turn up among the older properties here. An L-shape conversion adds a dormer to both the main roof and the outrigger, producing an L-shaped upstairs layout. It often works as the middle ground for an older home that needs more than a single dormer can give, without the planning difficulty a full mansard brings in this setting.
Every Washington home is different, and the best loft conversion is the one that works with the structure already there. We design around your roof rather than from a standard template, checking ridge height, head height at the wall plate, chimney breast positions and where a new staircase can land before proposing a layout. In a village where the external design has to earn its consent, that groundwork does double duty: it shows what the space can deliver, and it steers the design towards what is realistically supportable. You will leave the first visit with a clearer view of both.
Worthing is our base, and Washington is a short run up the A24, comfortably inside our regular working area. We know the general planning environment across RH20 and the villages along the foot of the Downs, including the split between National Park addresses and the district beyond it, and we are used to plots where access, scaffolding and deliveries need thinking through before the first van arrives. You get a local team on site, consistent standards throughout the build, and a crew that respects the home they are working in.
Our team and specialist partners work to a finish that stands up to close inspection: plumb walls, flush trims, clean plaster lines and joinery finished properly. That care counts for more where new work has to sit comfortably against an older house and is seen from open country behind it. Everything is built to current Building Regulations, and we coordinate with your Building Control inspector at the relevant stages. Completed projects are shown in the gallery below, and we are happy to talk through details and references at the first visit.
Six stages take a Washington loft conversion from the first visit to the finished room. Our trusted architectural partners cover the design work and any application, and we build it and hand it over. A few responsibilities stay with you by law, including Party Wall notices, listed building consent and the Building Control submission, and those are worth raising with a surveyor, architect or the authority early rather than late.
The first step is a free visit to your Washington home. We measure up, look at how the roof is framed, check head heights and ridge clearance, and talk through what the space could realistically deliver. There is no cost and no obligation to proceed.
Bring us existing drawings and we will price from those. Where there are none, our trusted architectural partners take the design stage on, from layout planning through to technical drawings, so you deal with one project team rather than several. The quote and an outline build programme follow the drawings.
Washington village addresses sit inside the South Downs National Park, so a planning application or Lawful Development Certificate goes to the South Downs National Park Authority rather than to Horsham District Council. Where one is needed, our architectural partners can prepare and submit it on your behalf. We would always recommend confirming the position for your own property directly with the authority, and discussing any Party Wall requirements with a surveyor or architect before work starts. Party Wall notices are the homeowner's legal responsibility and cannot be served by the builder.
On-site construction starts once consents, drawings and structural calculations are in place. Timescales vary with the conversion type and the property, and we set out an indicative programme at quote stage. The opened roof is kept weatherproof throughout, and we plan scaffolding and deliveries around the village lanes so that access and parking for neighbours are disrupted as little as possible.
You appoint Building Control, either your local authority or an approved inspector, and the inspections are booked at the stages the work requires. We build to current Building Regulations and work alongside whoever you appoint so nothing is missed at the points that matter.
With the final sign-off in place on your side, the finished loft is handed over. Store the completion certificate and the paperwork that comes with it alongside your deeds, since it gets asked for whenever the house is sold.
A selection of recent loft conversion projects completed around Washington, the RH20 villages and the wider Sussex coast, covering a range of conversion types and property ages. If you would like to see examples closer to your own home, get in touch and we will share relevant projects.
The notes below are general context for Washington homeowners considering a loft conversion and do not constitute legal advice. Always confirm the position for your property with the South Downs National Park Authority, and where relevant with an architect, planning consultant or party wall surveyor, before any work starts.
Planning authority. The village lies inside the South Downs National Park, so applications go to the South Downs National Park Authority, while Horsham District Council provides other local services.
National Park. Roofline changes are judged against the wider downland setting, so lower-impact conversions generally reach consent more smoothly than large dormers or mansards.
Conservation area. A designated conservation area covers part of the village, where permitted development rights are tighter and external detailing is looked at closely.
Same postcode, different position. Neighbouring RH20 villages sit outside the Park, so what applied at a nearby address is not a reliable guide to your own.
Permitted development. Outside the conservation area many conversions still proceed under permitted development, subject to the usual limits and to any Article 4 Direction, with a Lawful Development Certificate worth having for your records.
Party wall. On terraced and semi-detached homes, serving any Party Wall notice is the homeowner’s legal responsibility and cannot be done by the builder.
Apex is based in Worthing and covers Washington along with the villages either side of it below the escarpment, including Storrington just to the west, the Wealden village of Ashington a little further up the A24, and Findon back towards Worthing, and on towards Steyning, Wiston and Thakeham. Washington is a short run up the A24 from our base, which keeps site visits easy to arrange and the build straightforward to run.
The first step is a free site visit. We measure up, assess the roof structure and available head height, and talk through realistic options for the space, including what the National Park position is likely to mean for your property. From there our trusted architectural partners can take on drawings and any planning application, and you will want to confirm the planning position directly with the relevant authority and discuss any Party Wall requirements with a surveyor or architect before the build starts.
Apex works on loft conversions across Worthing, Brighton & Hove and the wider West Sussex coast. The pages below give a closer look at
the housing, planning and conversion types we see in each area. If your town or village isn’t listed, we likely still cover it, get in
touch for a quick check.
The questions Washington homeowners ask us most often about loft conversions. If yours is not here, send it through the contact form and we will answer it directly.
Timescales vary with the conversion type, the size and condition of the property and the consents involved. A rooflight conversion is generally the quickest, with dormer, hip-to-gable, L-shape and mansard builds taking progressively longer. Alongside the on-site build you need to allow for architectural drawings, structural calculations and, where required, planning approval, which tends to take longer here because the application goes to the South Downs National Park Authority and the design is assessed against the wider landscape. Working on a village plot can add a little to the programme as well, since scaffolding and deliveries need more planning. We will give you a realistic timeline for our part of the work at quote stage, and your architect or planning consultant is best placed to estimate the design and consent phase.
It depends on the property and where in the village it sits. Washington lies inside the South Downs National Park, so applications go to the South Downs National Park Authority rather than Horsham District Council, and permitted development rights are more limited inside a National Park than outside one. A designated conservation area covers part of the village, and inside it the external detail is assessed more closely again. A listed property will also need listed building consent, which is separate from planning permission. Away from those constraints many conversions still proceed under permitted development, subject to the national rules on volume and position and to any Article 4 Direction. Where an application or Lawful Development Certificate is needed, our trusted architectural partners can prepare and submit it on your behalf, and we would always recommend confirming the position for your specific property with the authority. Building Regulations apply to every loft conversion and are separate from planning.
In most cases, yes. Once the roof is opened up it is kept weatherproof, and most of the build happens above the existing first-floor ceiling. Expect noise and dust at points along the way, but staying put is usually practical. Steel installation and cutting in the new staircase are typically the most disruptive stages, and we flag both in advance so you can plan around them. On a village plot we will also agree where the scaffolding and skip can sit before the start date.
Industry research has long suggested a well-built loft conversion can add meaningful value, though the actual uplift depends on the property, the local market and the quality of the finish. In Washington, where the supply of homes is small and buyers are drawn by the setting below the Downs and the walking on the doorstep, an extra bedroom or bathroom tends to be well received, particularly by families who would rather stay than try to find something larger in the same spot. A conversion designed to sit quietly within the roofline usually holds its value best in a National Park village. For many homeowners the extra room also takes away the immediate pressure to move.
The working figure is a floor-to-ridge height of roughly 2.2 to 2.3 metres, measured from the top of the existing ceiling joists up to the underside of the ridge. Fall short of that and a dormer or mansard becomes the way to manufacture the headroom, whereas a rooflight conversion depends on the height being there already. Roofs rarely match expectations in either direction, so we measure at the free site visit rather than work from the age or size of the house, and we will say plainly if the numbers do not stack up.
It comes down to your roof shape, the space you want to gain and how far the external roofline can change. As a broad steer in a National Park village, a rooflight conversion or a carefully designed rear dormer is often the most straightforward route, with an L-shape where there is a two-storey rear outrigger. The hipped-roof semis and detached homes among the later housing can suit a hip-to-gable, frequently paired with a rear dormer. A mansard is the most demanding option in planning terms here. We will recommend the best option for your specific property at the free site visit.
Yes, without exception. The Building Regulations apply to every loft conversion in the country whether or not a planning application is involved. What they cover is structural stability, usually steel beams and strengthened floor joists; fire safety, meaning escape routes, fire doors and alarms; the new staircase and its headroom; and thermal and acoustic insulation between the new space and the rooms below. The submission and the inspections sit with you as the homeowner, through the council or an approved inspector, and we build to the standards and coordinate with whoever you appoint.
