Expand your home without the cost of moving.
Architectural integration and structural precision.
Extending a home requires far more than simply adding floor area. It demands safe load-bearing structural alterations, complex steelwork (RSJs), and meticulous roofline integration to ensure the new space performs perfectly. Tarj Construction delivers extensions across London and Essex through a strictly managed approach. We coordinate everything from deep foundation trenches to Part L compliant thermal upgrades, ensuring your new living space is structurally sound, legally certified by Local Authority Building Control (LABC), and feels like a natural continuation of the original building.
Complete Extension Construction
From structural planning to
completed extension works.
Planning & Structural Preparation
Successful extensions begin with careful preparation, technical review and proactive construction risk management to prevent delays and budget overruns across your London or Essex property.
Foundations & Structural Integration
New extension works must connect safely and reliably to the existing structure, monitored closely through our quality assurance & site oversight services.
External Construction
External works must protect the building while helping the extension feel consistent with the original property.
Interior Construction & Finishing Works
Internal works are completed to create a practical, cohesive and handover-ready new space.
Compliance & Handover
Final checks and rigorous project governance & documentation help ensure the extension is safe, compliant and ready for use.
Why Build an Extension
Creating more space while improving how your home works.
Increased Living Space (Improve, Don't Move)
Protected Property Value
Improved Layout & Functionality
Better Thermal Performance
Clear steps. Controlled delivery.
How house extensions are delivered.
01. Initial Consultation & Feasibility
02. Structural & Regulatory Planning
03. Pre-Construction & Site Setup
04. Foundations & Structural Knock-Throughs
05. Construction & Interior Fit-Out
06. Final Inspection & Handover
Thinking about extending your home?
Expand your space beautifully, safely, seamlessly, intelligently.
Frequently asked questions
Not always. Many single-storey rear and side extensions fall under Permitted Development (PD) rights across London and Essex, meaning you don't need full planning permission. However, there are strict limits on height and footprint. We help you assess your PD rights and can guide you through the formal planning process if required.
If your extension involves digging foundations near a neighbour's property or altering a shared boundary wall, you must comply with the Party Wall etc. Act 1996. We provide early guidance on this process to ensure you serve the correct notices to your neighbours, preventing costly legal delays before the build begins.
In most cases, yes. We understand that moving out is expensive and disruptive. We set up strict dust barriers, temporary weatherproofing, and safe access routes. While there will be some unavoidable noise and dust during the 'knock-through' phase, we manage the site carefully and perform a final builders' handover clean to return your home to a pristine state.
We manage the entire Building Control process for you. Even if your extension doesn't need planning permission, it must comply with strict UK Building Regulations for structural safety, insulation (Part L), and fire safety. We coordinate all stage inspections with the Local Authority (LABC) or Approved Inspector to secure your final Completion Certificate.
Unexpected costs usually come from poor upfront planning or hidden ground conditions. We conduct thorough site assessments and apply rigorous construction risk management before digging starts. By establishing a fixed, transparent scope of works and actively managing our trades, we protect you from the unexpected variations common with unmanaged building projects.
A standard single-storey rear extension usually takes between 12 to 16 weeks, while a double-storey or complex wrap-around can take 16 to 24 weeks. We provide a clear construction programme on day one, ensuring materials are ordered in advance and our trades are scheduled seamlessly so your project doesn't sit idle.




