Dormer Loft Conversion
A dormer gains full head height inside the roof. It needs steels to carry it and the dormer cheek construction detailed in the structural design.
A loft conversion lives or dies on the structure. Head height, floor joists, steel positions, stair access, it all has to work before a single drawing goes to the council. As loft conversion specialists, Xpanza designs conversions with the structural engineering built in from the start, producing loft conversion plans that are ready to price from and build from, whether it’s a dormer loft conversion, a hip-to-gable or a simple rooflight.
Each type changes the roof structure in a different way, which is why every one is designed and engineered together from the first draft.
A dormer gains full head height inside the roof. It needs steels to carry it and the dormer cheek construction detailed in the structural design.
A hip-to-gable squares off the roof to open up usable space, with the roof structure reworked and engineered to suit.
The simplest route. The roof shape stays as it is, with new floor joists and the stair opening still designed and calculated properly.
Brings the roof space of a bungalow into use, with structure, stairs and head height all solved together on the drawing.
The main types of loft conversion are a dormer to gain full head height, a hip-to-gable to square off the roof, rooflights to keep it simple, or a bungalow loft conversion to bring the roof space into use. From a small loft conversion to a full dormer, each one changes the roof structure, which means each one needs structural calculations: new floor joists, steels to carry the dormer, trimmers around the stair opening.
We design the conversion and engineer it as one job. Planning drawings where permission is needed, permitted development confirmation where it isn’t, and structural calculations and drawings that satisfy loft conversion building regulations and show exactly what goes where.
You send the measurements and photos; we send back a coordinated pack covering design, planning and structural. One team, one fixed fee, no gaps between the drawing and the steel.
What the structure involves
Sized and specified to carry the new room, shown on dimensioned structural layouts.
Steel positions calculated and drawn, so the roof is supported wherever it is cut open.
The stair opening framed and engineered, with position, pitch and headroom solved on the drawing.
Five reasons clients bring the design, planning and structural work to one team.
Floor joists, steels and stair openings are part of the design from the first draft, not a problem discovered after planning.
Many loft conversions don’t need full planning permission. We confirm it before you spend money on an application you don’t need.
Dimensioned structural layouts showing joist sizes, steel positions and openings, so the work can be quoted accurately and built without constant questions.
The two things that undo loft conversions, awkward stairs and low headroom, are designed out before anything is submitted.
No separate engineer to brief, chase or pay. One quote, one team, one coordinated pack.
Measurements, photos of the roof structure, and what you want from the space. We confirm whether it’s permitted development or needs full permission.
Conversion type agreed, layout drawn, stairs positioned, head height checked. You react and adjust until it works.
Planning drawings and application where needed; structural calculations for joists, steels and openings, all coordinated with the design.
Construction-issue drawings ready for the build, and we answer site and building control queries on our work.
A loft conversion rarely travels alone. Here are the services that most often go with it.
Full drawing sets developed from your measurements, from concept through to construction issue.
See our architectural design service → 02Applications prepared, submitted and tracked through to a decision.
See how planning permission works → 03Calculations for beams, steels, joists and openings, prepared by our structural engineers.
Get your structural work checked → 04Single and double-storey extensions with planning drawings and structural calculations included.
See what’s possible for your extension →Straight answers to the questions we’re asked most about loft conversions, from planning rules to head height. If yours isn’t answered here, call 07446 197853.
Many loft conversions fall under permitted development, but not all, and the rules differ between Wales and England. We check what applies to your property and confirm it, including a lawful development certificate where you want it in writing.
As a rule of thumb, around 2.2 metres between the existing ceiling joists and the ridge gives you workable options. Less than that and the choices narrow. Send us the measurements and we’ll tell you honestly what’s possible before you spend anything.
New floor joists to carry the room, steels to support the roof where it’s cut open, trimmers around the stair opening, and the dormer cheek construction where there’s a dormer. Our structural calculations cover all of it.
Most of the calendar time on a loft conversion is the planning decision and the build itself, not the drawings. On the design side, tell us your deadline at the start and we’ll confirm honestly whether we can meet it. Indicative timelines are shown in our cost calculator when you build your estimate.
Yes, but trussed roofs need more structural work than traditional cut roofs, because the trusses are doing more of the holding up. We design the steels and supports accordingly, so it’s fully engineered rather than improvised on site.
Stair position is one of the first things we solve on the drawing, because building regulations set the rules on pitch and headroom. Getting it right on paper is what stops it becoming a problem on site.
Send us your measurements, photos of the roof structure and what you want from the space. We’ll confirm the route, quote a fixed fee and get the design moving.