
Professional House Extension Solutions for Mountnessing Residents
Looking for professional house extension services in Mountnessing? Our experienced team of qualified architects provides comprehensive design solutions for residential projects across Mountnessing and the surrounding Enfield area. With deep local knowledge of Mountnessing's planning policies, building regulations, and architectural heritage, we deliver innovative designs that respect local character while meeting modern requirements.

A recent extension project in the Brentwood area
Our Mountnessing team brings extensive local knowledge and professional expertise to every project. We understand Mountnessing's unique architectural character, planning policies, and building regulations, ensuring your project progresses smoothly through the planning and building control processes. With years of experience working across the Enfield area, our architects have developed strong relationships with local planning authorities, building control officers, and other key stakeholders.
Navigating planning requirements in Mountnessing requires local expertise and up-to-date knowledge of Enfield Council's policies. Our architects understand the specific requirements for extensions in the area and can guide you through the planning application process, ensuring your proposal has the best chance of approval. We provide advice on design considerations, sustainability requirements, and community consultation processes.
Mountnessing has a diverse housing stock and we have experience extending all property types in the area. Our architects adapt designs to suit the character and structure of each home, whether that means matching original brickwork on a period property or creating a contemporary contrast on a more modern home.
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Covering CM15 & surrounding postcodes
Guide prices for house extensions in the Brentwood area. Every project is different — we provide a detailed, itemised quote after a free site visit.
| Extension Type | Typical Cost |
|---|---|
| Single Storey Rear Extension | £30k – £60k |
| Double Storey Extension | £47k – £102k |
| Side Return Extension | £21k – £43k |
| Wrap-Around Extension | £51k – £111k |
| Loft Conversion (Dormer) | £34k – £55k |
| Kitchen Extension | £26k – £51k |
| Basement Conversion | £68k – £170k |
| Garage Conversion | £13k – £26k |
Prices are guide figures for 2026 based on projects in the Essex area. PD = Permitted Development (no formal planning application needed in most cases). Actual costs depend on specification, site conditions, and scope.

Professional single storey extension design and planning for ground floor expansions
Typical: 6-12 weeks
Two-storey home extension design maximizing space and value
Typical: 8-16 weeks
Garden-facing extensions creating seamless indoor-outdoor living
Typical: 6-10 weeks
Narrow extensions utilizing side garden space efficiently
Typical: 6-12 weeks
Specialized kitchen and dining space extensions for modern living
Typical: 8-14 weeks
Converting attic space into valuable living areas
Typical: 6-10 weeks
Underground extensions creating additional living space
Typical: 12-20 weeks
Expert guidance through planning applications and permitted development
Typical: 8-16 weeks
Comprehensive extensions combining rear and side elements for maximum space
Typical: 10-18 weeks
Comprehensive whole-house renovation and modernization services
Typical: 12-24 weeks
Expert structural engineering services including underpinning and load-bearing work
Typical: 8-16 weeks
Converting garages into functional living spaces for bedrooms, offices, and studios
Typical: 4-8 weeksFrom the first phone call to moving into your new space — here is what to expect at every stage.
We visit your Mountnessing property, discuss your vision, assess feasibility, and give you honest guidance on costs and planning routes.
Our architects create detailed plans, 3D visuals, and construction drawings tailored to your Mountnessing home and how you want to live in it.
We prepare and submit your planning application, liaise with the local authority covering Mountnessing, and handle building regulations documentation.
Our vetted builders bring the design to life. We oversee the build, conduct regular site visits, and manage quality at every stage.
Final inspections, building control sign-off, snagging checks, and handover — your new Mountnessing space is ready to enjoy.
Our house extension services in Mountnessing cover the full spectrum of design and planning needs. We specialize in single-storey extensions, double-storey extensions, rear extensions, side extensions, kitchen extensions, loft conversions, and basement extensions. Our designs respect local architectural character while incorporating modern living requirements and energy-efficient solutions.
Whether your Mountnessing project requires planning permission or falls under permitted development rights, our team provides expert guidance and support. We understand Enfield Council's specific requirements and can advise on the most appropriate approach for your extension project. Our comprehensive planning services ensure your project progresses smoothly through the approval process.

Extension completed in the Brentwood area
Our Mountnessing building control services include detailed construction drawings, structural calculations, fire safety assessments, and accessibility compliance reviews. We understand the specific building control requirements for extensions in the Enfield area and can advise on structural solutions, thermal performance standards, and sustainability requirements.
Choosing the right architect for your Mountnessing project is crucial for success. Our team offers a combination of professional expertise, local knowledge, and personal service that sets us apart from other architectural practices. We provide comprehensive extension services with a focus on quality, efficiency, and client satisfaction.

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Plan your dream kitchen extension in London. Explore side-return, rear and wrap-around options with 2026 costs, planning tips and design inspiration for every budget.

Updated 2026 price guide for house extensions across London. Costs for single storey, double storey, loft conversions and more — broken down by area and project type.
Ready to start your house extension project in Mountnessing? Contact our expert team today for a free consultation and detailed project assessment. We offer competitive rates, professional service, and local expertise that ensures your project's success. Our Mountnessing extension services are designed to meet your specific needs, whether you're planning a rear extension, loft conversion, or complete home transformation.
Discover our comprehensive range of house extension solutions in London and surrounding areas
Professional single storey extension design and planning for ground floor expansions
Two-storey home extension design maximizing space and value
Garden-facing extensions creating seamless indoor-outdoor living
Narrow extensions utilizing side garden space efficiently
Specialized kitchen and dining space extensions for modern living
Converting attic space into valuable living areas
Call now to speak with our expert team. Get instant responses and professional guidance for your extension project.