A loft conversion is one of the smartest ways to add a room to your home. You gain a genuine extra floor — a bedroom, a home office, an ensuite, or a quiet retreat — without losing a single metre of garden or extending your footprint. But “loft conversion” is not one thing. There are several distinct types, each suited to a different roof shape, budget and end result, and choosing the right one for your particular Horsham home makes all the difference between a cramped attic room and a space that genuinely feels like part of the house.
In this guide we walk through the three most common types we build across Horsham — Velux, dormer and hip-to-gable — plus a couple of variations worth knowing about. We also look at which tends to suit the different kinds of property you find around the town, from the Victorian terraces near the centre to the 1930s semis of Roffey and the newer homes out at Broadbridge Heath.
Velux (rooflight) conversions
A Velux conversion, sometimes called a rooflight conversion, is the simplest and most affordable option. The existing roof shape stays exactly as it is — no dormers, no external building work — and light comes in through Velux windows fitted flush into the roof slope. Inside, we strengthen the floor to take everyday use, insulate throughout, fit a proper staircase, and finish the room with electrics, plastering and decoration.
The catch is headroom. A Velux conversion only works if your loft already has enough height, typically a minimum of around 2.2 metres from the ceiling joists up to the ridge. Where you have that height to begin with, it is the quickest and cheapest route to a beautiful new room, and because nothing changes on the outside it almost always falls within permitted development. Many of Horsham’s detached and larger semi-detached homes, particularly around the established streets near the town centre, have the roof volume to make a Velux conversion work brilliantly.
Rear dormer conversions
A dormer is the workhorse of the loft conversion world, and the most popular type we build in Horsham. It involves extending the roof outwards at the rear of the house to create a box-shaped structure with vertical walls and a flat ceiling. Where a Velux conversion limits you to the space beneath the existing slope, a dormer adds real, usable floor area and full standing height across the extended section, so the finished room feels like a proper storey rather than a converted attic.
Full-width rear dormers are especially popular because they turn the entire loft into one generously proportioned room with consistent headroom throughout — ideal for a master bedroom with an ensuite, or a large home office. Because the work is at the back of the property, most rear dormers proceed under permitted development without a full planning application, which keeps the timeline shorter. For the many semi-detached and terraced homes around Horsham where a Velux alone would not give enough height, a dormer is usually the answer.
Hip-to-gable conversions
A hip-to-gable conversion is the specialist option for houses with a hipped roof — the type where the roof slopes inwards on the side of the property rather than meeting a flat, vertical gable wall. That inward slope eats into the usable loft space and often leaves too little room for a comfortable conversion on its own. A hip-to-gable extends the sloping side up to a new vertical gable end, reclaiming all that lost volume and squaring off the space.
This type is particularly relevant in Horsham because so many of the town’s inter-war and post-war semis — the 1930s to 1970s housing you see across Roffey, Holbrook and the streets around Trafalgar Road — were built with exactly this hipped roof shape. On its own a hip-to-gable adds width; combined with a rear dormer, it creates the largest possible loft room from the available roof, with the gable giving you width and the dormer giving you depth. For the right property it is transformational.
L-shaped dormers and ensuite lofts
Two variations are worth a mention. An L-shaped dormer combines a main rear dormer with a second dormer over a rear addition or “outrigger”, creating an L-shaped room that can accommodate a bedroom and a separate bathroom. It suits period properties with a rear projection, of which Horsham has plenty. And whatever the base type, most loft conversions we build include an ensuite or shower room — the combination of a new bedroom with its own private bathroom is what makes a loft conversion such a valuable addition. The main technical challenge is routing the plumbing and soil connection up to the roof, which we plan carefully at the design stage.
Which type suits your Horsham home?
As a rough guide, it comes down to your roof shape and the height you already have. If you own a larger detached or semi-detached home with generous roof height, a Velux conversion may give you everything you need at the lowest cost. If you have a standard semi or terrace and want a proper full-height room, a rear dormer is usually the sweet spot between space and value. And if your house has that tell-tale hipped roof — common across the 1930s semis of Roffey and Holbrook — a hip-to-gable, often paired with a dormer, is likely to be the route that unlocks the most space.
Period terraces near the town centre and Causeway often suit L-shaped dormers thanks to their rear projections, while newer homes out at Broadbridge Heath and Southwater vary, so a quick look at the roof is the only reliable way to say for certain. The right answer is always specific to the individual house.
The practical checks that matter
Whichever type you choose, a loft conversion involves structural work that changes how your roof carries its load, so it is not a job for guesswork. Steelwork needs specifying correctly, the floor needs strengthening to a habitable standard, and fire safety and escape provisions must meet Building Regulations. Most conversions need Building Regulations approval even when they are permitted development on the planning side, and the two should never be confused. Head height, staircase position and the space you can spare on the floor below for the new stairs are all things worth checking early.
Talk to a local loft specialist
The best way to know which loft conversion suits your home is to have someone who builds them look at your roof. We carry out loft conversions throughout Horsham and the surrounding West Sussex area, and we are happy to visit, assess what your roof can take, and talk you honestly through the options and what each would cost. From the first structural assessment to the final coat of paint, you deal with one team and one clear plan.
If you are considering converting the loft at your Horsham home, get in touch for a free, no-obligation consultation and we will help you find the right approach for your property.