How Long Does a Loft Conversion Take?

When planning a loft conversion, one of the most common questions homeowners ask is: how long will it take? Whether you’re creating a new bedroom, home office, or en-suite, understanding the typical timeline helps you manage expectations, budget efficiently, and plan around your household routine.

While every loft conversion is unique, most follow a similar path—from initial design through to final decoration. The exact duration can vary depending on the type of conversion, the size of the property, and whether planning permission is required. However, a well-organised project can typically be completed within 5-7 weeks.

The Three Main Phases of a Loft Conversion

Every loft conversion—whether it’s a rear dormer, L-shaped dormer, hip to gable, or eaves conversion—follows three key stages:

1. Design and Planning Phase

This is where your dream loft takes shape. The process includes:

• A detailed property survey by architects and structural experts

• Drafting multiple design options tailored to your space, needs, and the type of loft conversion

• Addressing access, fire regulations, and structural feasibility

Once the design is finalised, we handle any necessary planning permission or building control submissions. If your property is in a conservation area or has specific planning constraints, this stage may take a bit longer—but our team works proactively with local authorities to prevent delays.

Planning Tip: While some loft conversions fall under permitted development rights, many in North London—especially in conservation areas—require full planning permission, which can take up to 8 weeks depending on the borough.

2. Pre-Build Preparation

This is the often-overlooked setup stage, where materials are ordered, scaffolding is erected, and site safety is established. You’ll see things like skips arriving, scaffolding going up, and the first access point into the roof being created—usually with minimal disruption to your daily life.

By the end of week 2, structural elements of the roof (like steel supports) are typically in place, especially for dormer or hip to gable conversions.

3. Construction Phase (5–7 Weeks)

This is where the transformation happens. Here's how it typically unfolds:

Weeks 1–2:

• Scaffolding and structural supports installed

• Roof work begins (cutting out for dormers or gables)

• Initial floor joists and roof modifications start

• Minimal disruption—most of the work occurs externally or within the loft space

Weeks 3–4:

• Internal framework, insulation, and ventilation installed

• Dormer structures are completed and windows fitted

• Plumbing and electrics roughed in

• Work remains largely contained to the loft

Weeks 5–7:

• The stairwell is installed, marking the connection to the rest of your home

• Carpentry, plastering, electrical finishes, and second-fix plumbing completed

• Walls painted, flooring laid, and any bespoke joinery added

  
  

By the end of week 7—often sooner—your new space is ready for decorating and furnishing.

Fast-Track Options: Velux or eaves-only conversions may be completed in 3–4 weeks. More complex builds like L-shaped dormers or hip to gable conversions usually run closer to 6–7 weeks.

Factors That Can Affect Your Timeline

• Type of Loft Conversion: Simpler roof light conversions are quicker. Rear dormers, hip to gable, and L-shaped dormers take longer due to structural work.

• Planning Delays: If full planning is needed, allow additional time for approvals.

• Weather: Extreme weather can slow exterior work, particularly roofing stages.

• Structural Surprises: Occasionally, we uncover issues (e.g. older timberwork, low head height) that need to be addressed mid-build.

• Customisation: Bespoke features like built-in storage or en-suites can add days but deliver long-term benefits.

Reducing Disruption

At Sunlight Lofts, we pride ourselves on keeping disruption to a minimum. The majority of structural and build work is done from outside or within the loft itself, with the internal breakthrough happening only in the final stage.

Our approach is:

• Clean

• Efficient

• Coordinated with your schedule

We work closely with you to keep things on track, update you regularly, and ensure your loft conversion is delivered on time—without sacrificing quality.

Your Next Step

A loft conversion is one of the smartest ways to add value, comfort, and space to your home. With Sunlight Lofts, most North London projects are completed in just 5 to 7 weeks, thanks to our expert in-house team and smooth project management. Contact us now for a free quote and find out exactly how quickly we can turn your underused loft into your favourite room in the house.