"How long will it take?" is usually the second question, straight after price. The honest answer has two halves, and most people only ever hear about the second one.

The half that happens before anyone turns up

Build work is the visible part. It is rarely the longest part.

Design and drawings. Somebody has to draw what you are building and work out how it holds up. On a conversion involving new floor joists, steels and a dormer, that means an architect or technician and a structural engineer.

Building regulations. A loft conversion is notifiable work. Structure, fire safety, escape routes, insulation, stairs and headroom all get checked and signed off. This is not optional and it is not a formality.

Planning permission — sometimes. Many conversions fall under permitted development, but not all. Conservation areas, flats, previous extensions that have used up your allowance, or anything unusually large can all mean a full application, which takes considerably longer.

Party wall. If you share a wall with a neighbour and the work affects it, the Party Wall etc. Act 1996 comes into play, and notice periods are fixed by law rather than by anybody's diary.

This first half commonly runs to a couple of months. It can be started long before you want work to begin, and pushing it forward is the single biggest thing within your control.

The half you actually see

Once on site, a typical conversion runs roughly like this.

Set up and access

Scaffold goes up, protection goes down through the house, and a route to the loft is established. Short, but it is when your home stops feeling entirely like yours.

Structure

The real work. New floor structure to carry a habitable load, steels in, and — if you are having one — the dormer formed and made weathertight. This is the noisiest, most disruptive stage and the one most exposed to weather.

Weathertight and openings

Roof windows in, dormer roofed and clad, the new space closed to the elements. A visible turning point: from here on, most work is inside.

Staircase

Usually the moment the rest of the house notices, because it takes a bite out of the floor below. Position, headroom and fire separation were all decided at drawing stage — this is where those decisions become real.

First fix

Electrics, plumbing, insulation and structural detailing, all before anything gets covered up. Inspections happen here.

Plaster and second fix

Boarding, plastering, then sockets, radiators, lighting and doors.

Decoration, flooring and handover

The finishing stage, plus final sign-off from building control.

Most straightforward conversions run six to ten weeks on site. Larger dormers, complex roofs, or awkward access push that out.

The four things that add time

1. Late decisions. Every choice not made before it is needed becomes a pause. Windows, stairs, sanitaryware and flooring should be settled early.
2. Weather during the roof stage. Unavoidable and worth building into your expectations rather than your programme.
3. Surprises in the existing structure. Older properties hide altered joists, undersized timbers and previous DIY.
4. Changing your mind mid-build. Entirely your right — just understand that a change at second fix costs several times what the same change costs on a drawing.

The projects that finish on time are the ones where every decision was made before the scaffold went up.

Living through it

You can usually stay in the house. It is dusty, it is loud during structural work, and there will be days without water or power while things are connected. Plan around the noisy stages if you work from home.

Get a realistic programme for your house

A timeline is only worth having if it is drawn against your actual roof, your actual access and your actual plans.

Send through your drawings if you have them, or photographs and a description if you do not, and you will get a written quotation with a stage-by-stage programme — including the approvals, so you can see the whole picture rather than just the weeks on site.