A loft conversion can add significant value to your home whilst creating much-needed extra space. Understanding the timeline and what happens each week will help you prepare properly and know whether your project is running to schedule. Most loft conversions take between six and ten weeks, depending on complexity, the type of conversion, and whether any unexpected issues arise.
Weeks 1-2: Structural Work and Access
The first fortnight focuses on creating safe access and beginning the structural work. Your builder will erect scaffolding around your property and potentially install a temporary staircase if you're having one fitted internally. You'll hear considerable noise during this phase as the team strips out the existing roof structure where necessary.
Steel beams typically arrive and are installed during week one or two. These crucial structural elements support your new floor and roof, transferring loads to the existing walls. This is heavy, technical work requiring building control inspection. Expect your builder to cut openings for the staircase, and you may need to vacate certain rooms below whilst this happens for safety reasons.
The building inspector will make their first visit during this period to check the structural calculations match what's being installed. Any discrepancies need addressing immediately, so don't be alarmed if work pauses briefly whilst adjustments are made.
Weeks 3-4: Roof Structure and Weatherproofing
Once the structural framework is secure, attention turns to the roof itself. For dormer conversions, the dormer structure goes up during week three. This is weather-dependent work, so rain can cause delays. Your builder will work quickly to make the space watertight, installing roof windows or dormer windows and getting the new roof covering in place.
Expect your home to be partially exposed to the elements for a few days. Reputable builders use heavy-duty sheeting to protect your property, but you might want to move valuables from upper floor rooms as a precaution. The new roof covering, whether tiles, slate, or other materials, gets installed to match your existing roof as closely as possible.
By the end of week four, your loft should be completely weatherproof. This is a major milestone – you can relax knowing rain won't damage your home's interior.
Weeks 5-6: First Fix Electrics, Plumbing and Insulation
With a watertight structure in place, the first fix trades arrive. Electricians run cables for lighting, sockets, and any other electrical requirements. If you're adding an en-suite bathroom, plumbers will install pipework and waste runs during this phase. You'll need another building control inspection to check the insulation meets current regulations before anything gets covered up.
Insulation is critical in a loft conversion as heat rises and the space will be difficult to keep comfortable without proper thermal protection. Your builder will insulate between and under the rafters, typically using rigid foam boards or quilted insulation. Don't skimp here – poor insulation means higher energy bills and an uncomfortable room.
The staircase often gets installed during week five or six, making access much easier for the trades. Plasterboard goes up on walls and ceilings towards the end of this phase, transforming the space from building site to recognisable room.
Weeks 7-8: Plastering and Second Fix
Plasterers need several days to skim all the plasterboard surfaces and create smooth walls and ceilings ready for decorating. This is wet work that needs proper drying time – rushing this stage leads to cracked plaster later. Keep the space well-ventilated with windows open when weather permits.
Once plastering is complete and reasonably dry, second fix work begins. Electricians return to fit light fittings, sockets and switches. Plumbers install sanitaryware if you've added a bathroom. Internal doors get hung, skirting boards and architraves go up, and the space starts looking finished.
Weeks 9-10: Decorating and Final Touches
The final weeks involve decorating, laying flooring, and completing any snagging items. You might handle the decorating yourself to save money, though many homeowners prefer their builder to finish everything. Carpet or other flooring goes down last to protect it from damage.
Your builder will conduct a final clean and arrange the last building control inspection. Once approved, you'll receive your completion certificate – essential documentation that proves the work meets building regulations and protects your home's value.
Before starting your project, it's wise to get multiple quotes from reputable loft conversion specialists to compare not just prices but also proposed timescales and what's included. A detailed quote helps you understand exactly what to expect during each phase of your conversion.