What to Expect During a Building Project: Step-by-Step Timeline

Undertaking a home building project - whether it's a house extension, loft conversion, or full-scale renovation - is a major investment. For many homeowners in Cardiff and across the UK, it’s a journey filled with both excitement and uncertainty. Knowing what to expect at each stage of the process can help ease concerns and provide clarity from the outset.

As experienced builders serving Cardiff and surrounding areas of South Wales, RGB Construction has guided countless clients through successful projects of all sizes, from the simple to the complex.

Below, we’ll explain the building project stages in the UK - from initial planning right through to handover - giving you a clear, honest, and professional overview of the construction process explained step-by-step.

1. Initial Consultation & Site Visit

The journey begins with an initial consultation. At this stage, you and your builder (hopefully a reputable one!) will discuss your vision, requirements, and budget. This meeting may take place on-site, particularly if you’re looking to extend your home or convert existing spaces like a loft or garage.

What happens at this stage:

• Discuss project goals and timeline

• Share ideas, inspiration, or sketches

• Assess the site for feasibility

• Initial ballpark cost estimation

• Identify any constraints (e.g., access, neighbouring properties)

Top Tip: Prepare a wish list and gather some visual inspiration from sites like Pinterest or Houzz to clearly convey your vision.

2. Design Phase & Architectural Drawings

Once your ideas are confirmed, you’ll need a professional design. This might involve an architect or a building designer, depending on the complexity of your project. Good architectural drawings not only bring your vision to life but also form the foundation for planning applications and build specifications.

This stage includes:

• Developing initial concept drawings

• Revising plans to meet your preferences and regulations

• Producing technical drawings and detailed specifications

• Liaising with a structural engineer if required

3. Planning Permission & Building Regulations

Not all projects require planning permission, but many do - especially extensions, loft conversions, or outbuildings. Even if permission isn’t needed, all work must comply with UK Building Regulations.

Your builder or architect will help with:

• Submitting planning applications to your local authority (e.g., Cardiff Council)

• Preparing building control documents

• Organising any necessary surveys (e.g., structural, drainage, ecology)

Typical timeframes:

• Planning permission: 8 - 12 weeks

• Building regs approval: 2 - 6 weeks

Top Tip: Consider utilising the Planning Portal UK where you can check whether you need planning permission for your home project.

Read: 10 Things to Ask Your Prospective Builders

4. Final Quote & Contract Signing

Once all approvals are in place and the plans are finalised, your builder can provide a formal quotation and building contract.

At this point you should receive:

• A detailed, itemised quote

• Payment schedule (usually in stages)

• Construction schedule/timeline

• Terms & conditions

• Insurance and warranties information

5. Site Preparation & Groundworks

Now the real physical work begins! The first few days often involve clearing the site, setting up temporary facilities (e.g., scaffolding, site office, storage), and preparing for foundations.

This might include:

• Site clearance (trees, old structures, rubbish removal)

• Setting out the building lines

• Digging and pouring foundations

• Installing drainage systems

• Erecting scaffolding

• Laying sub-base for driveways or patios

This stage is key for structural integrity and can take anywhere from 1 - 3+ weeks, depending on the size of the project. Your builder will be able to provide you with a more accurate timeframe beforehand based on the works to be completed and the current environment and situation of where the works are to take place.

6. Structural Work: Walls, Floors & Roof

Once groundworks are complete, structural work starts. This stage is the meat of the project and may include building extensions, internal walls, new floors, or installing steel beams for open-plan layouts.

Typically involves:

• Bricklaying or timber framing

• Installing lintels, joists, and supports

• Building internal partitions

• Roofing structure and tiles/slates

Timeframe: Can range from 3 - 10 weeks depending on complexity.

7. First Fix: Electrics, Plumbing & Insulation

‘First fix’ is a term often used within the building trade to describe the installation of key services before plastering. It includes all the behind-the-scenes work that brings power, heat, and water into your property.

First fix typically includes:

• Running electrical cabling

• Installing plumbing pipework

• Setting out positions for sockets, lights, radiators

• Insulating walls and ceilings

• Fitting ventilation ducting

Your property may still look like a building site at this point, but a lot of magic is happening under the surface.

8. Plastering & Internal Finishes

Once the first fix is complete, walls are plastered and internal structures start to take shape. It's during this stage that the initial vision and plans start to become a more visual reality.

This stage often includes:

• Drywall installation and plastering

• Floor screeding

• Skirting boards and coving

• Installing staircases (if required)

After plastering, a drying period is essential before decorating begins.

9. Second Fix: Fixtures & Fittings

This is the exciting part where your project truly starts looking like a home again. The second fix is all about bringing in the final fittings and making everything work.

Second fix typically includes:

• Fitting electrical outlets and switches

• Installing radiators and boilers

• Plumbing fixtures like taps and toilets

• Hanging doors and fitting ironmongery

• Kitchen and bathroom installation

• Tiling, painting and decorating

10. Final Inspection & Handover

Before officially finishing, your builder should walk through the site with you for a final snagging list. Any small defects or incomplete elements are noted and resolved.

Final stages include:

• Building Control sign-off

• Clean-up and rubbish removal

• Delivery of certificates (e.g., electrical, gas safety)

• Handover of keys and warranties

At this point, your project is officially complete, and you can enjoy your transformed home.

Additional Considerations:

Timelines

Every project is unique, but here’s a very rough idea:

Communication is Key

Choose a builder that keeps you in the loop with regular updates. At RGB Construction, we pride ourselves on clear, professional communication throughout every phase of the project.

Keeping it Legal

Always work with insured and accredited builders. This ensures compliance with UK laws and provides peace of mind.

Read: 5 Tips to Increase the Asking Price

A Transparent, Step-by-Step Guide to Your Build

Understanding the construction process explained from start to finish takes the mystery out of building work. Whether you’re tackling a major home renovation, a modest kitchen extension, or an ambitious double-storey garage conversion, knowing what to expect at each stage can help reduce stress, avoid delays, and ensure a smooth journey from blueprint to reality.

At RGB Construction, we combine local knowledge, expert craftsmanship, and genuine customer care to deliver building work across Cardiff and South Wales that’s as stress-free as possible.

Considering a project? Speak to our friendly, professional team today and let’s start planning something special for your home.

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