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Welcome to
J.M.B Design & Build Ltd,

where quality comes first.

We design, build and create beautiful spaces within your home.

J.M.B Design & Build Ltd is a building firm based in Hertfordshire run by James Boulton. James and his team of qualified craftsmen have more than 25 years of experience in the industry. 

We offer professional and experienced help with your projects from concept with our in-house Architectural Planning and Design team that work with regulatory specialists, build with our qualified team of experienced craftsmen offering a bespoke service to completion with our top finish decorators. Helping to match your vision, needs and budget.

J.M.B Design & Build Ltd prides itself on quality, workmanship and referrals from happy clients is the main source of all new work.

Contact us today and see how we can help transform your home.

JMB Introduction

Award Winning Construction Company

Operating in Hertfordshire, London and surrounding counties


Loft Conversions

Previous five-star review loft conversion project locations include Barnet, Brookmans Park, Enfield, Potters Bar and Whetstone.


House Extensions

Previous five star review house extension project locations include  Enfield, Goffs Oak, Haringey,

Potters Bar, St Albans and Whetstone.


Home Renovations

Previous five-star review home renovation project locations include Barnet, Enfield, Goffs Oak, Potters Bar, Radlett and Whetstone.


We are very pleased with our kitchen extension. JMB did an excellent job. James set himself high standards and he was only content when these were achieved. This has culminated in a very successful project. Everyone loves our kitchen! We would not hesitate to recommend JMB.



Houzz Service Award Winner 2022, 2023 and 2024
We received this award thanks to 100% 5 Star feedback for projects carried out in the last 12 months.

Houzz Service Award

J.M.B Design & Build Ltd is a full service building construction company dedicated to building and improving residential and commercial structures according to client needs and desires.


We specialise in transforming your home into what you always wanted. Be it a loft conversion, extension or a new build from scratch. You can be rest assured that at JMB, quality, precision and excellence comes first.

Based in Hertfordshire but also covering London and Essex, the team at JMB is ready to give your space whatever updates it requires.

Just give us a call or enquire online today and we’ll get back to you as soon as we can with a quote.

Contact us today to see how we can help create your dream space.

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