Apex builds loft conversions across Arundel and BN18: dormer, hip-to-gable, Velux, mansard and L-shape. Architectural support sits in house, and we confirm which planning authority covers your address before any design work begins. Get in touch for a free, no-obligation quote.
Thinking about a loft conversion in Arundel? This is one of the few towns on our patch where the first question is not about your roof at all. It is about which authority your address answers to. The South Downs National Park boundary runs through Arundel rather than around it. The higher, older part of the town lies inside the Park, where the South Downs National Park Authority handles planning, while the lower ground towards the river and the main road sits outside it under Arun District Council. Two neighbours a short walk apart can be dealing with different bodies and different policies.
That matters because it changes who decides, what weight the setting carries, and how a roofline alteration is likely to be judged. It is not a reason to expect difficulty. It is a reason to confirm the position for your specific address before anyone draws anything, since the boundary does not follow any line a homeowner would guess from the street. We establish it at the first visit, along with whether the property sits inside the town conservation area or is listed, and only then talk about what to build.
Working across Arundel and the wider BN18 area, we take a joined-up approach from the first drawing to the finished room. Our in-house architectural support covers layout planning, structural coordination and technical drawings, and can prepare and submit a planning application or Lawful Development Certificate to whichever authority applies. We build to current Building Regulations throughout. Contact us for a free, no-obligation quote on your Arundel loft conversion.
Which conversion suits an Arundel home depends on the roof you are starting with, how much of the new floor clears usable head height, and how visible any change to the roofline would be. Five types come up across BN18. In a town this closely looked at, where rooftops are seen from higher ground and from the approaches, the external impact of each option carries more weight than it would elsewhere.
The type that returns the most usable floor area, and in Arundel the one most shaped by where the house sits. A dormer projects out from the roof slope to give a flat ceiling and standing room across a useful width. On the later housing outside the conservation area a rear dormer may fall within permitted development. Within the historic town it will be judged on proportion, position and materials, and by the National Park Authority rather than the district council, so the design work needs to answer that from the outset.
Suited to hipped roofs, where the side of the roof slopes inward rather than rising to a flat wall, which is common on Arundel’s later residential development away from the old town. Rebuilding that slope to a full gable recovers the volume the hip takes away and often makes a marginal roof workable. Because it changes the outline of the house seen from the side, it is a far more straightforward proposition outside the protected core than within it. It pairs often with a rear dormer.
The lightest touch of the five, and frequently the sensible starting point in a town where so much is protected and so many roofs are on show. Nothing outside changes beyond the plane of the glazing: we strengthen the structure, insulate, board the floor out and fit rooflights for daylight. It holds the roofline exactly as it is, which is the single most helpful thing a scheme can do here. The trade-off is that it borrows head height rather than creating it, so it needs the room to already be there.
The biggest change of the five, rebuilding a roof slope to near vertical for maximum floor area and headroom. Full planning permission is almost always required and the appearance of the house changes substantially. In a historic town with a nationally recognised skyline, this is the hardest of the five to achieve within the old core, so it belongs to larger properties on the outer edges. Worth testing with the relevant authority and a planning consultant before design time goes into it.
Works where the house has a two-storey rear projection to build onto, with a dormer added to both that projection and the main roof to form an L-shaped upstairs. It gives more than a standard dormer without the planning weight of a mansard, and because the work sits to the rear it is often the more realistic option on a house that is prominent from the front. Not every Arundel property has that projection, so it is one of the first things we look for.
The best conversion is the one your structure and your planning position will both support, so we design around the house rather than from a template. In Arundel that means settling the authority question and the conservation position first, because they set the boundaries of what is worth designing. Within those, we get precise about the head height you will genuinely stand up in once the new floor and roof lining are in, and where a staircase can land. You leave the first visit with a realistic picture rather than an optimistic one.
We are based in Worthing and work right along this stretch of the coast and inland up the Arun valley, so a site visit or a call-out mid-build in Arundel is easy to arrange. We know the general planning picture across the district and are used to properties where the National Park Authority, rather than the council, is the body making the decision. You get a local team on site, the same standards from first day to last, and a crew that treats your home as somewhere people are living.
Our team and specialist partners work to a finish that stands up to close inspection: level floors, plumb walls, clean plaster lines and well-fitted joinery. In a town where roofs are genuinely on display, seen from the higher ground and from every approach, external work has to look like it was always meant to be there. All work is carried out to current Building Regulations and we coordinate with your Building Control inspector at the relevant stages. Recent projects are shown in the gallery below.
An Arundel conversion moves through six stages. The design and any application are handled by our in-house architectural support, and the build is done by us. A few responsibilities cannot be passed over and we point them out at the start: Party Wall notices, appointing Building Control, and listed building consent where the building is listed. Take each of those up with a surveyor, architect or the relevant authority.
We come to your Arundel home, measure floor to ridge, look at the roof structure and work out where a staircase could land. We also establish which planning authority covers your address, and whether the property is in the conservation area or listed. In this town that groundwork is worth as much as the measurements. No cost, no obligation.
If you already have drawings we will price against them. If not, our in-house architectural support takes the design on, producing the layout and the technical drawings the application needs. Where the National Park Authority is the decision maker, the drawings and the supporting case are prepared with its policies in mind rather than the district's. A detailed quote and outline programme arrive alongside the drawings.
Where a planning application or Lawful Development Certificate is needed, our architectural partners can prepare and submit it on your behalf, to the South Downs National Park Authority or to Arun District Council depending on where your property sits. Confirm that position for your own address first. Talk to a surveyor or architect about Party Wall requirements before work starts, since those notices are the homeowner's legal responsibility and cannot be served by the builder.
Building starts when the consents, drawings and structural calculations are all in hand. Duration comes down to the type of conversion and the property, with an indicative programme issued at quote stage. The roof is kept weatherproof for the whole time it is open. Access in the older part of town is tighter than almost anywhere else we work, so scaffold, deliveries and skip positions get agreed with you well before anything arrives.
Appointing Building Control is your call, through the district team or an approved inspector, and the visits are booked by you. We build to the current regulations and give timely notice as each stage completes. Note that Building Control runs entirely separately from planning, so it is unaffected by which of the two planning authorities covers your address.
Once the final inspection passes, the room is handed over. Keep the completion certificate filed with your property records together with the planning or consent documents, because in Arundel a buyer's solicitor tends to look closely at what was approved and by which authority.
A cross-section of what we have completed around West Sussex, covering various property types, roof forms and conversion approaches. Let us know what yours is and we will pull out the nearest examples.
The notes below are general context for Arundel 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 or Arun District Council, and where relevant with an architect, planning consultant or party wall surveyor, before any work starts.
Planning authority. The National Park boundary runs through the town: the higher, older part sits inside it under the National Park Authority, lower ground towards the river outside it under Arun District Council. Confirm which covers your address.
Conservation area. One covers the historic town, where permitted development rights are usually tighter and a full application is more likely.
Listed buildings. Arundel holds a high concentration. Listed building consent is separate from, and additional to, planning permission.
Permitted development. On later housing outside the conservation area, many conversions proceed under permitted development, subject to the usual limits and any Article 4 Direction.
River Arun flood risk. Low ground near the river falls within Environment Agency tidal flood zones, bearing on ground works and access rather than on a loft.
Party wall. On semi-detached and terraced homes, serving any Party Wall notice is the homeowner’s legal responsibility and cannot be done by the builder.
Apex works across Arundel and the surrounding Arun valley, with Littlehampton, Angmering and the villages between them inside the same run, so arranging a visit is straightforward and the build keeps its pace once it starts.
The first step is a free site visit. We measure up, assess the roof structure and head height, and establish which planning authority covers your address, which in Arundel is the thing that shapes everything that follows. From there our in-house architectural support can take on the drawings and any application, and you will want to confirm that position for your address directly with the relevant authority and discuss 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.
Questions Arundel homeowners raise most frequently. Anything we have not covered, send it through the contact form.
It depends on the conversion type, the size and condition of the property, and the consents involved. Rooflight conversions are usually quickest, with dormer, hip-to-gable, L-shape and mansard builds taking progressively longer. In Arundel the consent phase is the least predictable part, particularly on a property inside the National Park or the conservation area where the design has to be justified as well as drawn. We give you an indicative programme 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 your address, and in Arundel that is a genuine question rather than a formality. The South Downs National Park boundary runs through the town, so some properties are decided by the South Downs National Park Authority and others by Arun District Council, with different policy emphasis on each side. Inside the conservation area covering the historic town, permitted development rights are usually tighter and a full application is the likely route, with dormer proportion, position and materials examined closely. If the building is listed, listed building consent is required on top and extends to internal alterations. On later housing outside those designations many conversions fall within permitted development, subject to the national limits and to any Article 4 Direction. A mansard or a raised roof normally needs permission wherever it is. Building Regulations apply either way and are separate from planning.
Usually, yes. The roof is kept weatherproof once it is opened and most of the work happens above the existing ceiling. Expect noise and dust at points, particularly during steel installation and when the staircase is cut in. Access in the older part of Arundel is tighter than in most towns we work in, so the practical planning around scaffold, parking and deliveries is worth settling with you early, and we do that before the build rather than during it.
A well-built conversion has long been regarded as one of the better returns among home improvements, though the actual figure depends on the property, the quality of the finish and the local market at the time. Arundel is a town where property is bought partly for its character, so a conversion that respects the building tends to be received better than one that simply maximises floor area. Having the right consents cleanly documented also matters more here than in most places. It is worth taking an estate agent’s view alongside ours.
Expect to need somewhere near 2.2 to 2.3 metres between the top of the existing ceiling joists and the underside of the ridge, measured before the build begins, as the finished floor and the roof lining will absorb part of it. Older roofs in Arundel are rarely even across their span, so one reading taken at the centre can give a flattering picture. We measure it properly at the free visit and tell you plainly if it does not work, particularly where the planning position leaves a rooflight scheme as the only realistic route.
As a broad steer: within the historic town, rooflights are usually the realistic starting point, with a well-proportioned rear dormer the next step where the position allows it. On the later housing further out, a hipped roof often suits a hip-to-gable paired with a rear dormer, and a house that already has a gable end may need only the dormer. Where there is a two-storey rear projection, an L-shape keeps the work to the rear, which helps on a prominent property. We will recommend the right option for your specific property at the free site visit.
Yes, on every loft conversion, whether planning permission is needed or not, and whichever authority happens to cover your address. The regulations deal with structural stability, generally steel beams and strengthened floor joists; fire safety, meaning escape routes, fire doors and alarms; staircase design and headroom; thermal insulation; and sound separation from the rest of the house. In an older property, meeting them without harming the fabric being protected takes more thought at design stage. You appoint Building Control and book the inspections, through the district team or an approved inspector.
